Hearing loss is one of the most common causes of disability worldwide. The aim of the study was to compare the demographic structure and the results of hearing tests in people qualified for hearing aids over the last 25 years. The material covered 1246 patients qualified for hearing aids in the years 1996–2001 and 2016–2021. Patients were divided into two groups according to the time of qualifying for hearing aids. Group 1 (G1) consisted of 759 people qualified in the years 1996–2001, and Group 2 (G2) comprised 487 people qualified in the years 2016–2021. Statistical analysis was performed on the results of pure tone threshold audiometry and the demographic structure in both groups. Patients in G1 had statistically significantly elevated hearing thresholds (HT) in the air conduction range at frequencies from 2000 to 8000 Hz in relation to G2 patients. The opposite situation was observed for the bone conduction threshold. G2 patients had significantly elevated bone conduction HT at frequencies from 250 to 1000 Hz compared to G1 patients. The age structure in both groups was similar; however, the gender distribution was statistically significantly different. In G1 women accounted for 40%, and in G2, they became the dominant gender (53%). Over the last twenty years, there has been a change in the structure of patients qualified for hearing aids. Although the age has remained similar, today, patients decide to use hearing aids at an earlier stage of hearing loss than 25 years ago. Modern women began to use hearing aids much more often. According to data published by the World Health Organization (WHO), it is estimated that in 2019, around 1.57 billion people worldwide had a hearing impairment, and 62.1% of them were over the age of 50 .The basic consequence of disability, which is hearing loss, and in particular sensorineural hearing loss, is a reduced ability to recognize speech (speech in noise), a problem with communication and an increased risk of isolation, which results in a significant decrease in the quality of life.In people with hearing loss who cannot be qualified for surgical treatment, the only way to alleviate the effects of hearing impairment and improve speech understanding is the use of various types of hearing aids. Their primary purpose is to improve the hearing of sounds by amplifying incoming signals. The US Food and Drug Administration (FDA) states that the hearing aid should be considered as a personal sound amplification product (PSAP) . RecentlIt is estimated that although more than 400 million people worldwide would benefit from hearing aids , unfortuThe importance of the aspect of improving hearing through the use of hearing aids is evidenced by the MarkeTrak research organized in the United States since 1989, which allows us to analyze not only the needs of the patients but also the problems reported by the patients. Following the example of the MarkeTrak research, EuroTrak research has been organized in Europe since 2011 .An essential element for the best fitting of hearing aids is still an interview with the patient (anamnesis), information about the sound environment in which the patient lives, assessment of the degree of intelligence and manual skills, evaluation of the patient’s expectations and audiometric measurements and audiological tests of the hearing organ.The audiometric tests are necessary in order to qualify for hearing aids and include pure tone audiometry—determination of the hearing threshold curve as a function of frequency (HTL—hearing threshold level), determination of the level of comfortable hearing (MCL—most comfortable loudness level), the level of discomfort of hearing (UCL—uncomfortable loudness level) or speech intelligibility testing in a free field.Particularly noteworthy is the result of pure tone threshold audiometry. It allows the patient to be pre-qualified for hearing prostheses and, above all, to be qualified by the state or other organizations for a full refund or partial refund of the hearing aid costs. Extending reimbursement to two hearing aids is a very important step that enables patients to maximize the benefits of their hearing aids .The aim of this study is to compare audiometric results and demographic structure in patients qualified for hearing aids in two different periods (1996–2001 and 2016–2021).The material covered 1246 patients of the Audiological Clinic of the Mazovian Bródno Hospital randomly selected from among people qualified for hearing aids with air and bone conduction devices in the years 1996–2001 and 2016–2021. The patients were briefed information about the research, and those who agreed to participate signed informed consent before the study started. The patients ranged in age from 18 to 95 , and the qualifications were performed by the same medical team in each case. Pure tone threshold audiometry was performed on each patient included in the study. Additionally, from patients who qualified in the years 2016–2021, data on the type of hearing aid they chose during the qualification were collected.Hearing-impaired patients were divided into two groups according to the time of qualifying for hearing aids. Group 1 consisted of 759 people who qualified for hearing aids in the years 1996–2001, and Group 2 consisted of 487 people who qualified in the years 2016–2021.t-test were used. The statistical tests were performed in R statistical software.Statistical analysis was performed on the results of pure tone threshold audiometry, which were the basis for qualification for hearing aids, and the demographic structure in both groups. Descriptive statistics and testing of hypotheses using the parametric repeated-measures Student’s The analysis of the demographic structure of the patients in both groups using the Shapiro–Wilk test did not show statistically significant differences in the age of people qualified for hearing aids over the two periods of observation .In both groups, more than half of the people qualified for hearing aids were over 70 years of age, and the largest population were patients in the 71–80 age group .However, the demographic structure of patients covered by hearing aids has changed in terms of gender distribution. Twenty-five years ago, hearing aids were used significantly more often by men, and they constituted about 60% of the group. Currently, the ratio of women to men has evened out and even showed a slight advantage of women over men (53% vs. 47%) .Statistical analysis of audiometric test results showed no statistically significant differences in the average hearing threshold (dBHL) between the right and left ear within particular groups .The patients were divided into four groups in terms of grades of hearing loss as follows: mild (21–40 dB), moderate (41–60 dB), severe (61–80 dB) and profound (≥81 dB). Nearly 50% of patients in Group 2 had mild or moderate hearing loss, which is a significantly higher percentage than in Group 1 .The comparison of the mean hearing thresholds between group 1 and group 2 for both bone conduction  and air t-test), it was found that patients from Group 1 had significantly elevated air conduction hearing thresholds for sounds with frequencies from 2000 to 8000 Hz compared to patients from Group 2. This difference ranged from 2 to 5 dB and was highest at 4000 and 6000 Hz. Simultaneously, it was observed that Group 2 patients had significantly elevated bone conduction hearing thresholds at frequencies from 250 to 1000 Hz relative to Group 1 patients, and this difference ranged from 2 to 5 dB and was highest at 250 Hz . This may be related to the fact that women live longer than men and are more likely to suffer from age-related hearing problems. In addition, modern women have less visible appliances at their disposal, which reduces their aesthetic concerns. Changing the structure of employment in society has also meant that women need to use hearing aids at work more often than they used them when working at home, which probably makes them more inclined to use hearing aids with prostheses.The main goal of each method of fitting hearing prostheses is to select the device that corrects the hearing defect and to set its characteristics to improve the hearing comfort of the hearing-impaired person in the best possible way and in particular to improve the level of speech intelligibility.According to the accepted standards, an adult patient (over 26 years of age) qualifies for hearing aids with bilateral hearing loss on average above 40 dB for frequencies corresponding to the speech range. It should be noted, however, that this is an “administrative” criterion and does not take into account so-called “steep” (“high-frequency”) hearing losses. It also does not take into account the lack of intelligibility of colloquial speech even with smaller hearing losses for pure tones. That is why the fitting process itself is so important. Especially patients with sensorineural hearing loss have difficulty with understanding speech even with carefully selected parameters of hearing aids. In 2022, the prospective study proved that hearing rehabilitation therapy significantly improves speech understanding in hearing aids in patients with sensorineural hearing loss [According to the National Institute of Deafness and Other Communication Disorders (NIDCD), approximately 28.8 million adults in the United States may benefit from wearing hearing aids. In 2016, 3.65 million hearing aids were issued in the United States, and the average age of first-time hearing aid wearers was 70. It was also found that a significant number of people waited up to 6 years from the time they first noticed their hearing loss to purchasing their first hearing aid .In our study, the patients in the years 1999–2001 (Group 1) made the decision to use hearing aids at more advanced stages of hearing loss than similar decisions the patients made today (Group 2). This statement is supported by the fact that patients with mild or moderate hearing loss constituted 49.9% of the whole Group 2, which is significantly higher than in Group 1 at 42.8%. Moreover, the hearing threshold for air conduction in the frequency range from 2000 to 8000 Hz was 2–5 dB elevated in Group 1 than in Group 2. This is especially important due to the fact that these frequencies are responsible for “the speech understanding”. These results are in line with the latest population studies, which show that more and more patients with hearing loss decide to use hearing aids. In the case of patients with moderate hearing loss (40–59 dB), a significant increase in the prevalence of the use of hearing aids in the group of patients from 2011 to 2016 was found, compared to the study group between 1999 and 2004 ,24.At the same time, patients from Group 2 had significantly higher hearing thresholds in the bone conduction range at frequencies from 250 to 1000 Hz compared to patients from Group 1, which resulted in greater difficulties with the selection of hearing aids.Similar results were obtained in Poland in 2016 based on the EuroTrak study, where people over 74 were dominant among people with prostheses—48.4% . No tendContrary to our observations, American scientists did not notice changes in the sex structure of the prosthetic people, which we noted in our research . This diIn our study, in Group 2, we also analyzed the types of hearing aids chosen by patients. Among them, classic behind-the-ear (BTE) hearing aids were the most popular—84%. In patients under 60 years of age, in-the-canal devices (ITC) accounted for 28.6%, while in the group aged 60 years and over, they accounted for only 13.4%. The lower popularity of ITCs in elder patients may be due to the fact that BTEs are easier to use, have larger batteries, are harder to lose and, perhaps crucially, have a lower price compared to ITCs. However, the greater popularity of ITC in younger people may be due to the aesthetic qualities of this type of hearing aid, and above all, they are less visible.Importantly, apart from aesthetic considerations, no statistically significant differences were observed in the effectiveness of Lyric Extended Wear (EW), behind-the-ear open hearing aids (RITE) and fully in-the-canal (CIC) hearing aids .It is noteworthy that only 13.3% of our patients used binaural hearing aids. This percentage is much lower compared to the results of the Eurotrak study, where in 2009 in Germany, 60% of patients using hearing aids had hearing aids in both ears, and in the USA in 2008, 74% of patients used hearing aids in both ears . This maAt the same time, it should be emphasized that as many as 96% of hearing aid owners declared that their hearing aids at least sometimes improve their quality of life. Hearing aid users are 14.5% less exhausted at the end of the day compared to non-hearing aid users with similar hearing loss and are less likely to experience depression or memory loss . It has 1.Patients who decided to wear hearing aids in 1999–2001 (Group 1) had significantly higher hearing thresholds in the air conduction range at frequencies from 2000 to 8000 Hz in relation to patients with modern prostheses (Group 2).2.Patients nowadays (Group 2) decide on hearing aids at an earlier stage of hearing impairment compared with patients in Group 1.3.Patients in Group 2 had significantly higher hearing thresholds in the bone conduction range at frequencies from 250 to 1000 Hz compared to patients in Group 1, which may cause greater difficulties with the selection of hearing aids.4.The age structure of patients qualified for hearing aids has remained at a similar level over the last 25 years. On the other hand, the gender structure of people assisted by hearing aids has changed significantly.


Bananas are one of the most popular fruits in the world, providing food security and employment opportunities in several developing countries. Increasing the anthocyanin content of banana fruit could improve the health-promoting properties. Anthocyanin biosynthesis is largely regulated at the transcriptional level. However, relatively little is known about the transcriptional activation of anthocyanin biosynthesis in banana.Musa acuminata MYBs that were predicted by bioinformatic analysis to transcriptionally regulate anthocyanin biosynthesis in banana. MaMYBA1, MaMYBA2 and MaMYBPA2 did not complement the anthocyanin-deficient phenotype of the Arabidopsis thaliana pap1/pap2 mutant. However, co-transfection experiments in A. thaliana protoplasts showed that MaMYBA1, MaMYBA2 and MaMYBPA2 function as components of a transcription factor complex with a bHLH and WD40 protein, the so called MBW complex, resulting in the activation of the A. thaliana ANTHOCYANIDIN SYNTHASE and DIHYDROFLAVONOL 4-REDUCTASE promoters. The activation potential of MaMYBA1, MaMYBA2 and MaMYBPA2 was increased when combined with the monocot Zea mays bHLH ZmR instead of the dicot AtEGL3. This work paves the path towards decoding the MBW complex-mediated transcriptional activation of anthocyanin biosynthesis in banana. It will also facilitate research towards increased anthocyanin content in banana and other monocot crops.We analysed the regulatory activity of three The online version contains supplementary material available at 10.1186/s13104-023-06375-2. They are one of the most important food crops, particularly in the developing world [Bananas ng world . While tng world . Furtherng world .Dianthus caryophyllus) which have antifungal activity against the plant’s major pest Fusarium oxysporum f.sp. dianthi [Fusarium subspecies called Fusarium oxysporum f. sp. cubense (Foc) and threatens the global banana production [Flavonoids are a major group of plant specialised metabolites that share a basic structure of two aromatic C6-rings connected by a heterocyclic ring . Reorgan dianthi , 12. Theoduction . Transcroduction .(Zea mays), as well as PAP1 (PRODUCTION OF ANTHOCYANIN PIGMENT1/MYB75) and PAP2 (MYB90) from Arabidopsis  [ANTHOCYANIDIN SYNTHASE (ANS) and DIHYDROFLAVONOL 4-REDUCTASE (DFR) [Flavonoid biosynthesis is one of the best characterised pathways of the specialised metabolism and has been extensively studied in many plant species . In banahaliana) , 25. TheSE (DFR) –29.M. acuminata.In banana, 285 R2R3-MYB proteins have been identified in a genome-wide study, including several putative regulators of flavonoid biosynthesis . In addiMaMYBs, named MaMYBA1, MaMYBA2 and MaMYBPA2, with a possible role in the regulation of anthocyanin biosynthesis. As one of these MaMYBs was very recently published under the name MaMYBPA2 [in planta complementation experiments of the anthocyanin deficient A. thaliana regulatory mutant pap1/pap2 and co-transfection experiments in A. thaliana protoplasts .Here, we describe the regulatory properties of three MaMYBPA2 , we usedMaMYBs which have been previously assigned to a possible role in positive regulation of anthocyanin biosynthesis . Since all three MaMYB genes were detected in the haploid M. acuminata reference genome sequence DH (doubled-haploid) Pahang v2 [MYBs appear to be present in the same sub-genome, suggesting that they are different genes and not haplo-copies. We attempted to amplify the corresponding coding sequences (CDSs) on a template collection containing cDNA from different banana samples. The CDSs of all three MaMYBs were successfully amplified on cDNA derived from peel tissue of M. acuminata (AAA group) cultivar ‘Grand Naine’ grown in the field in Lucknow, India.We aimed to analyse the regulatory properties of three ahang v2 , 35, theA. thaliana pap1/pap2 double mutant  to complement the pap1/pap2 anthocyanin deficiency. While wild-type seedlings (Col-0: Nottingham Arabidopsis Stock Centre (NASC) ID N1092; Nö-0: NASC ID N3081) accumulated high levels of red anthocyanin pigments, pap1/pap2 seedlings did not. Although MaMYBA1, MaMYBA2 or MaMYBPA2 were successfully expressed in the transgenic seedlings , which Z. mays anthocyanin regulator C1 by generating transgenic A. thaliana overexpression lines. In their study, Lloyd et al. generated three independent ZmC1-expressing A. thaliana lines that did not show an increased anthocyanin content compared to wildtype. Similar results were obtained in transgenic tobacco. However, further experiments suggested that ZmC1 must interact with the maize bHLH ZmR to activate anthocyanin biosynthesis in the heterologous A. thaliana system [Z. mays and rice (Oryza sativa), are part of a different phylogenetic clade than the anthocyanin regulators from several dicots, such as A. thaliana or grapevine (Vitis vinifera) and further monocots, including onion (Allium cepa) and lily (Lilium hybrida). Experiments in snapdragon (Antirrhinum majus) have also shown that the monocot AcMYB1 can activate anthocyanin production in dicots [ZmC1 on ZmR in dicots suggest an explanation for our observations. For example, the MaMYBs may depend on their endogenous or at least monocot bHLH for effective activation of structural anthocyanin biosynthesis genes. To investigate the phylogenetic differences between anthocyanin biosynthesis regulating R2R3-MYBs from different plant species, an approximate maximum-likelihood tree was constructed  or Z. mays (ZmR) and the A. thaliana WD40 protein TRANSPARENT TESTA GLABRA1 (AtTTG1). Their potential to activate the promoters of AtDFR and AtANS, which are important structural genes of anthocyanin biosynthesis [MaMYBs was able to independently activate proAtANS or proAtDFR, which both contain conserved cis-regulatory elements, a slight activation of proAtDFR was detected when MaMYBA1 or MaMYBPA2 was combined with AtEGL3 and AtTTG1. In combination with AtEGL3 and AtTTG1, MaMYBPA2 showed the strongest activation of proAtDFR and was also able to activate proAtANS. In combination with ZmR and AtTTG1, the three MYBs MaMYBA1, MaMYBA2, and MaMYBPA2 showed a significant activation potential on proAtDFR and proAtANS. All three MaMYBs showed a higher activation potential in an MBW complex with ZmR and AtTTG1 than in combination with AtEGL3 and AtTTG1.To follow up this idea, we further investigated the regulatory properties of the three ays Fig.  in hypoctoplasts  with difynthesis , was anaMaMYBA1, MaMYBA2 and MaMYBPA2 are able to activate proAtANS and proAtDFR as part of an MBW complex and that MaMYBPA2 shows the strongest activation potential. Furthermore, MaMYBA1, MaMYBA2 and MaMYBPA2 show a higher activation potential when combined with the monocot bHLH ZmR instead of the dicot bHLH AtEGL3.These results show that MaMYBs in combination with ZmR and AtTTG1 instead of AtEGL3 and AtTTG1. It is conceivable that these differences impede the interaction between the tested MaMYBs and the dicot bHLH AtEGL3. Since MaMYBPA2 shows the highest activation potential and is also able to activate proAtANS in combination with AtEGL3 or ZmR, differences between the three MaMYBs affecting the interaction with the AtEGL3 are likely and should be further investigated. Interestingly, MaMYBPA2 did not complement the anthocyanin deficient phenotype of A. thaliana pap1/pap2 mutant seedlings, but was able to activate proAtANS and proAtDFR when combined with AtEGL3 in co-transfection experiments in A. thaliana protoplasts. Although previous studies have shown AtEGL3 expression in A. thaliana seedlings [MaMYBPA2. Furthermore, the At7 cell line used for co-transfection experiments was established more than 25 years ago. This long period of propagation in suspension cell culture has caused a number of genomic and transcriptomic changes [The phylogenetic differences mentioned above could explain the observed higher activation potentials of the analysed eedlings , it is p changes . These cMaMYBA1, MaMYBA2 and MaMYBPA2 have previously been analysed in embryogenic cell suspension, seedling, root and different developmental stages of leaf, pulp and peel [MaMYBA1 was strongest in pulp , MaMYBA2 expression was relatively low in all samples and MaMYBPA2 showed highest expression in seedlings and early developmental stages of pulp (S1). This gene expression pattern may indicate organ specific MaMYBA1, MaMYBA2 and MaMYBPA2 activity in banana. Since flavonoid biosynthesis is largely regulated at the transcriptional level, it would be particularly interesting to analyse the expression levels of MaMYBA1, MaMYBA2, and MaMYBPA2 in anthocyanin rich organs such as bract or pseudostem to correlate anthocyanin content with MaMYB transcript abundance.The expression profiles of and peel . The expMaMYB4. They found that the expression of MaMYBA1 and MaMYBPA2, together with MaDFR and MaANS, is decreased in plants overexpressing MaMYB4, compared to wildtype. These data support a proposed functionality of MaMYBA1 and MaMYBPA2 as transcriptional activators of anthocyanin biosynthesis in banana, as MaMYB4 could cause a feedback regulation of the positive regulators of anthocyanin biosynthesis, including MaMYBA1 and MaMYBPA2.Deng et al.  performeMaMYBPA2 can activate the banana ANS, ANR and LAR promoters. They also showed that MaMYBPA2 can partially rescue the proanthocyanin deficiency of the A. thaliana tt2-1 mutant. The reported ability of MaMYBPA2 to activate proMaANS supports the proposed role of MaMYBPA2 in the regulation of anthocyanin biosynthesis. However, the partial complementation of the proanthocyanin deficient phenotype of the A. thaliana tt2-1 R2R3-MYB mutant, as well as the ability to activate the banana ANR and LAR promoters, indicates a role in the regulation of proanthocyanidin biosynthesis. Such dual role in the regulation of flavonoid biosynthesis has previously been suggested for R2R3-MYB transcription factors from grapevine, blueberry (Vaccinium species) and apple  [A. thaliana, Z. mays and Petunia hybrida, anthocyanin biosynthesis is regulated by an MBW complex [MaMYBA1, MaMYBA2 and MaMYBPA2 are able to activate proAtANS and proAtDFR as part of an MBW complex with ZmR and AtTTG1 in planta. As shown in a previous study by Pucker et al. [MaMYBA1, MaMYBA2, and MaMYBPA2 are all known to contain a bHLH-binding consensus motif [MaMYBA1, MaMYBA2, and MaMYBPA2 is likely to depend on bHLH and WD40 proteins. Based on our tree  –43. In s complex , 44–46. r et al. , it is kus motif . Thus, tMaMYBA1, MaMYBA2, and MaMYBPA2 have the ability to transcriptionally activate expression of structural anthocyanin biosynthesis genes in an MBW complex with a suitable bHLH partner. The activation potential of the tested MaMYBs is increased when the MaMYBs are combined with the monocot bHLH ZmR instead of the dicot bHLH AtEGL3.The results presented, in particular the approximate maximum-likelihood trees and the co-transfection assays, show that This is a step towards deciphering the MBW complex-mediated transcriptional activation of flavonoid biosynthesis in banana. It also provides a basis for further research to increase anthocyanin production in banana, which could improve fruit quality and disease resistance.MaMYBA1, MaMYBA2, and MaMYBPA2 can activate two structural genes of anthocyanin biosynthesis from A. thaliana as part of an MBW complex. To further investigate the promotor activation potential of the MaMYBs, the co-transfection analysis could be expanded to other structural genes of anthocyanin biosynthesis, as well as promoters and bHLH and WDR candidates from banana. In addition, yeast two-hybrid or other protein-protein interaction experiments could be performed to investigate the affinity between MYB and bHLH proteins. To elucidate the regulatory role in banana and to confirm possible target genes, future studies should include an overexpression of the three MaMYBs in banana.The co-transfection assays revealed that Below is the link to the electronic supplementary material.Supplementary Material 1MaMYBA1, MaMYBA2 and MaMYBPA2 in A. thaliana pap1/pap2 seedlings. Table S1: Oligonucleotide primers used in this work. Table S2: IDs of protein sequences used for the construction of the phylogenetic tree.Supplementary Material 2: Figure


P = 0.34) for fasting glucose (per 1 mg/dL increment), 1.02  for HbA1c (per 1% increment), and 1.47  for fasting C-peptide (per 1 log increment). Sensitivity analyses, including Mendelian randomisation-Egger and weighted-median approaches, revealed no significant association between glycaemic characteristics and colorectal cancer (P > 0.20). In this study, genetically predicted glycaemic characteristics were not significantly related to colorectal cancer risk. The potential association between insulin resistance and colorectal cancer should be validated in further studies.Observational studies suggest that abnormal glucose metabolism and insulin resistance contribute to colorectal cancer; however, the causal association remains unknown, particularly in Asian populations. A two-sample Mendelian randomisation analysis was performed to determine the causal association between genetic variants associated with elevated fasting glucose, haemoglobin A1c (HbA1c), and fasting C-peptide and colorectal cancer risk. In the single nucleotide polymorphism (SNP)-exposure analysis, we meta-analysed study-level genome-wide associations of fasting glucose , HbA1c , and fasting C-peptide  levels from the Japanese Consortium of Genetic Epidemiology studies. The odds ratios of colorectal cancer were 1.01 (95% confidence interval [CI], 0.99–1.04,  The drastic alteration in diets and lifestyle due to industrialisation and economic growth has led to an increased colorectal cancer incidence in the Asian population2. In fact, nearly a half of the newly diagnosed and prevalent colorectal cancer cases in the last five years have occurred in Asia3. Therefore, identifying modifiable risk factors is essential for reducing the incidence of the disease and the associated socioeconomic losses.Colorectal cancer comprises a heterogeneous group of neoplasms influenced by a variety of environmental factors and genes7. Hyperglycaemia promotes glucose oxidation in intracellular mitochondria, and subsequent oxidative stress leads to DNA damage6. It is likely that proliferative and anti-apoptotic effects of insulin also promote colorectal tumour growth4. However, there are only a few epidemiological studies assessing the association between hyperglycaemia, hyperinsulinemia, or insulin-related traits and colorectal cancer, and the results remain inconclusive in Asians12. Although some observational studies suggest that metformin (a widely used hypoglycaemic agent) is associated with reduced colorectal cancer risk and cancer-specific mortality13, large-scale randomised controlled trials have not reported such a relationship14. Conflicting results also exist on the effect of thiazolidinediones (another type of glucose-lowering medication) on colorectal cancer16. These inconclusive results suggest that findings from observational studies may be distorted by confounding factors or reverse causation. Therefore, the causality between dysregulated glucose metabolism and colorectal cancer remains largely elusive.The pivotal role of impaired glucose tolerance and insulin resistance has been increasingly recognised in colorectal carcinogenesis17. MR uses genetic variants as instrumental variables to determine the unconfounded influence of exposure (glucose intolerance) on outcome . However, only a handful of MR studies have assessed the causality between glycaemic characteristics and colorectal cancer risk19, and none of these were from Asian populations. An MR study from the USA using an individual-level genome-wide association study  did not find any significant associations between insulin-related traits and incident colorectal cancer18. More recently, a relatively large-scale MR study from the UK Biobank  reported that genetically predicted fasting glucose and fasting insulin were not significantly associated with colorectal cancer risk19. Considering that genetic variants are heterogeneous in different ethnicities that may presumably affect the susceptibility of disease20, an MR study in Asian populations is warranted.Mendelian randomisation (MR) could overcome such biasesHence, in the present study, we leveraged large-scale Japanese samples including 7,936 colorectal cancer cases and performed an MR analysis to examine the association between genetically predicted measurements of hyperglycaemia (fasting glucose and HbA1c) and insulin resistance (fasting C-peptide) and colorectal cancer risk.21.The MR method estimates the relationship between the exposure and the outcome of interest using known genetic variants related to the exposure under the following assumptions: (i) the selected genetic instruments are associated with the exposure of interest; (ii) they are not associated with any confounding factors in the relationship between the exposure and the outcome; (iii) the association between the genetic instruments and the outcome is only through the exposure of interest22.As shown in Fig. https://www.ebi.ac.uk/gwas/), co-published by the National Human Genome Research Institute and the European Bioinformatics Institute . Given that GWASs for fasting C-peptide was extremely limited and none of the SNPs were met the baseline exclusion criteria  reaching a genome-wide statistical significance threshold (P < 5 × 10–8), with minor allele frequency > 0.01 in the East Asians of the 1000 Genomes Project. As of December 1, 2020, we identified 97, 94, and 23 instruments for fasting glucose, HbA1c, and fasting C-peptide, respectively. To minimise the potential confounding effects from linkage disequilibrium, we used the “clumping” function in PLINK  . Finally, we identified 34, 43, and 17 instruments for fasting glucose, HbA1c, and fasting C-peptide, respectively. Regardless of the statistical significance of the SNP-glycaemic trait associations in our samples, we used all the selected SNPs as instrumental variables to minimise biases from false negatives due to insufficient power24 and overfitting25. Detailed information for instrumental variables of each glycaemic trait is presented in Supplementary Tables To satisfy the MR assumption (i), instrumental variables for fasting glucose, HbA1c, and fasting C-peptide were systematically selected through previously published GWASs, as shown in Supplementary Figure 26, thereby violating the MR assumptions (ii) and (iii), we examined whether the selected instruments are associated with erythrocyte-related traits at the GWAS significance threshold (P < 5 × 10–8) using the PhenoScanner (available at http://www.phenoscanner.medschl.cam.ac.uk/phenoscanner) and Haploreg databases . The instruments included rs579459 for haemoglobin concentration; rs17509001 and rs13134327 for high light scatter reticulocyte count; rs6684514, rs7616006, rs4737009, rs12602486, and rs4820268 for mean corpuscular haemoglobin concentration; rs11248914, rs9914988, rs2748427, and rs57601949 for mean corpuscular volume; rs11964178, rs7776054, rs6980507, rs10823343, rs174594, and rs12819124 for red blood cell count; rs857691, rs9818758, rs837763, and rs17533903 for reticulocyte count; and rs282587 for reticulocyte fraction of red cells. Additionally, we examined whether selected SNPs, such as body mass index (BMI), smoking, alcohol intake, and physical inactivity, could be confounders of the association between glycaemic metabolism and colorectal cancer2. While some instruments were associated with these traits , manual selection of instrumental variables that may have pleiotropic effects is generally not recommended27. Therefore, we conducted an MR-Egger regression28 as a sensitivity analysis .Considering that several variants may affect HbA1c levels via erythrocyte biologyX) using the previously described formula as below:We calculated how much the selected genetic variant could explain the respective phenotype 29.30.-based prospective study, the Tohoku Medical Megabank (TMM) Community-Based Cohort study, the Japan Multi-Institutional Collaborative Cohort (J-MICC) study, and the Hospital-based Epidemiologic Research Program at Aichi Cancer Center (HERPACC). In the current MR study, genetic data for each glycaemic trait were available from JPHC, TMM and J-MICC within the J-CGE studies. The characteristics of each cohort are presented in Table 32, from the JPHC study.We obtained the summary statistics of the SNP-glycaemic trait (fasting glucose and HbA1c) associations from the Japanese Consortium of Genetic Epidemiology (J-CGE) studiesThe exclusion criteria included: participants with physician-diagnosed diabetes; participants on any diabetes treatment; participants with fasting (defined by ≥ 8 h) serum glucose ≥ 126 mg/dL (≈ 7 mmol/L for fasting glucose or fasting C-peptide) or HbA1c ≥ 6.5% (for HbA1c); people with missing data on fasting status. In total, we included 17,289 people with fasting glucose measurements , 52,802 people with HbA1c , and 1,666 participants with fasting C-peptides . The details of each GWAS are described in Supplementary Table https://humandbs.biosciencedbc.jp/hum0014-v1833, the JPHC case-cohort study-5 years , NAGANO study , HERPACC study , and J-MICC study ; further, summary-level GWAS data were extracted from the BioBank Japan (BBJ) study  model, which utilised the MR-PRESSO package v1.0. The IVW method with random effects was used to assess the relationship between genetically predicted glycaemic traits  and the risk of colorectal cancer.34. In the presence of directional horizontal pleiotropy, however, the IVW method may produce biased estimates35. To address such violations (MR assumptions (ii) and (iii)), we further applied multiple sensitivity analyses that are more robust to pleiotropic effects, including MR-Egger regression, weighted median, and MR-PRESSO analyses. The intercept term of the MR-Egger regression provides the indicator of unbalanced pleiotropy (P < 0.05 indicated significance)28. Nonetheless, the disadvantage of the MR-Egger approach is that it is affected by outliers or influential data points. At this point, the weighted-median analysis is useful because the approach can produce valid estimates if at least a half of the instruments are correct35. Finally, the MR-PRESSO method performs regression analysis of the estimates for SNP-outcome against the SNP-exposure to explore outlier SNPs36. Outliers were then removed from genetic variants whose causal estimates differ substantially from those of the other variants, and the IVW method for all variants was then performed. The funnel and leave-one-out plots were also obtained. The thresholds for nominal significance were set at P < 0.05.While the IVW method has great statistical power, this method requires a stringent assumption; all the instrumental variables are valid or “balanced pleiotropy”For the SNP-exposure analyses, we used participants from the J-CGE studies, as shown in Table P = 0.34) for fasting glucose (per 1 mg/dL increment) and 1.02  for HbA1c (per 1% increment) (Table P = 0.06) , suggesting no pleiotropic effect  for colorectal cancer were 1.01  Table , S3. We 6) Table . However6) Table –S4, the ct Table –S4.TableUtilising the genetic instrumental variables in the association between various glycaemic traits and colorectal cancer, we performed a large-scale MR analysis in the Japanese populations. There was no strong evidence for a relationship between fasting glucose and HbA1c levels and colorectal cancer. While we observed potential positive association between higher fasting C-peptide and colorectal cancer in our primary analysis using the IVW MR method, we did not observe this based on the MR-Egger or the weighted-median approach. However, since this is the first MR study to comprehensively evaluate the association of glycaemic traits with colorectal cancer in Asian populations, our findings need to be validated further.12. A meta-analysis from 18 studies showed a dose–response positive relation between fasting glucose levels and colorectal cancer across different study designs (case–control vs. cohort studies) and ethnicities (Europeans vs. Asians)5. Likewise, several cohort studies identified an elevated risk of colorectal cancer with higher HbA1c37, although two nested case–control studies from the USA found no association (presumably because case–control designs were extremely sensitive for selection bias and reverse causation)39. Furthermore, in an umbrella review of 30 observational studies, including 62,163 cases, colorectal cancer is one of the four cancer types associated with diabetes7. In contrast, our null findings were generally in line with recently published MR studies19. A study with 5,486 cases among 367,643 patient samples of European descent from the UK Biobank, which used 35 instrumental variables, reported an insignificant association of fasting glucose with colorectal cancer19. Using four SNPs, another individual-level MR study with 11,078 non-Hispanic white postmenopausal women, including 736 cases, found null associations between fasting glucose and colorectal cancer18. Effect estimates of MR meta-analysis for fasting glucose and colorectal cancer were 1.09 19. Hence, these findings provide limited evidence of a genetic role of hyperglycaemia per se in colorectal carcinogenesis.The present MR findings are inconsistent with the observational studies that suggest a positive link between hyperglycaemia and colorectal cancer risk11. For instance, several case–control studies10 and a cohort study11 over a 20-year follow-up period showed a non-significant relation between fasting insulin levels and colorectal cancer. In contrast, a nested case–control study 8 from Japan suggested a significant positive association between plasma C-peptide and colorectal cancer in men (OR [95% CI] comparing highest vs. lowest quartiles of C-peptide = 3.2 [1.4–7.6]). A recent meta-analysis of 27 studies with over 10,000 cases of colorectal adenomas 40 suggested a stronger positive association of insulin-related traits in non-Asians (summary OR [95% CI] for insulin = 1.67 [1.28–2.17] and for C-peptide = 1.59 [1.22–2.08]) than in Asians (summary OR [95% CI] for insulin = 1.10 [0.92–1.33] and for C-peptide = 1.27 [0.92–1.91])41. Given that Asians are more prone to insulin resistance for a given BMI than Caucasians42, the observed heterogeneity could be partially explained by the population difference or inherent biases of residual confounding and reverse causality. Collectively, we have conducted an MR study that is less susceptible to such biases because alleles are randomly assigned in meiosis and unaffected by the acquired factors21.Epidemiological evidence for the association of insulin and insulin-related traits with incident colorectal cancer has been inconclusive, particularly among Asians32, adding to the robustness of the estimates. Nonetheless, our sensitivity analyses, which were less sensitive to invalid genetic instruments, did not support this association. The two MR studies in non-Asians also did not show strong evidence for the insulin-colorectal cancer axis19. Non-significant findings from MR studies, including this study, might also arise from insufficient power. Indeed, recent large-scale MR studies supported a significant association between fasting insulin and colorectal cancer risk44. Other factors may include the diverse genetic instruments for insulin secretion, which might be associated with different colorectal cancer pathways34. For instance, among the selected instrumental variables, rs8050136 at the FTO22 might affect increased BMI45, thereby contributing to colorectal carcinogenesis31 partly via hyperinsulinemia, since obesity is a risk factor for increased insulin secretion46. This type of pleiotropy, known as vertical pleiotropy, is not a barrier in the causal inference of MR studies27. In contrast, some genetic variants could be associated with colorectal cancer through unknown pathways unrelated to insulin resistance . Nonetheless, we conducted multiple sensitivity analyses, including MR-PRESSO and Egger regression, suggesting no pleiotropic effect in our current study.We found suggestive evidence that genetic predisposition to insulin resistance (fasting C-peptide) may influence colorectal cancer risk in Asians in our primary analysis using the IVW MR method. However, the CI was too wide to make a definitive conclusion. Among several biomarkers indicating insulin secretion, C-peptide is a relatively stable biomarker with less sensitivity to fasting status and a longer circulating half-life47. Although insulin and IGF1 receptors are both expressed in normal and cancerous colorectal epithelia, their bioactivities are slightly different48. IGFs play a role in cell proliferation, whereas insulin is responsible for carbohydrate metabolism48. Since IGF1 can directly promote cellular proliferation through the Ras/MAPK (mitogen-activated protein kinase) and PI3K (phosphoinositide 3-kinase)-Akt (protein kinase B) pathways, the mitogenic properties of insulin may be mediated via IGF1 receptors or its hybrids48. The significant role of IGFs in colorectal tumorigenesis is supported by a recent MR study from the UK Biobank, including 52,865 colorectal cancer cases49. Although further studies are warranted, dysregulated insulin pathways, rather than a consequence of impaired glucose metabolism, might have a higher chance of increasing colorectal cancer risk.Experimental and clinical evidence supports a role for insulin and insulin-like growth factor (IGF) signalling systems in colorectal carcinogenesis51. Nonetheless, we admit that F-statistics, whose threshold of < 10 defines a “weak instrumental variable” in the MR study30, was limited to provide robust estimates for fasting C-peptide (F-statistic for fasting C-peptide: 1.08) and thus the current results should be interpreted cautiously. In addition to the limited explained variance for each glycaemic trait and the limited number of colorectal cancer cases, weak associations could potentially remain undetected. In particular, an observed marginal association between fasting C-peptide and colorectal cancer risk may be due to the limited power or due to the weak instrument bias. Therefore, we cannot eliminate a possibility that the observed marginal association may reach a statistically significant or may become totally insignificant when a sample size of colorectal cancer cases increases. In addition, subgroup analyses by disease aetiology should also require larger sample sizes. Therefore, further studies with sufficient sample sizes are warranted. Finally, there was a sample overlap between the exposure and the outcome datasets, leading to a non-null association22. Hence, the observed marginal positive association between fasting C-peptide and colorectal cancer risk might be overestimated. However, owing to the small proportion of such cases, the bias should be minimal.This is the first MR study that assessed the causality of glycaemic traits and colorectal cancer among Asian populations on a relatively large scale. The current MR framework can diminish confounding and reverse causality and potentially bias the observational findings. However, a limitation of our analysis included measurement errors, since all biomarkers were measured only once at the baseline survey. Due to the limited number of GWASs from East Asian populations, we have systematically identified the SNPs from publicly available GWASs in all ethnicities. Therefore, we cannot eliminate the possibility that some SNPs were not related to glycaemic traits in East Asians, which may lead to bias. Nonetheless, we have restricted the SNPs with minor allele frequency > 0.01 in East Asians as genetic instrumental variables and thus such bias should be small, if existent. In addition, for the sensitivity analyses, we only used the SNPs from the GWASs conducted in East Asians and confirmed that the MR results were generally comparable. For SNP-exposure analyses, the sample size was limited because we only included subjects with fasting status over 8 h after a meal, leading to the low precision of the exposure measurement; however, the explained variance in this study (2.48% for fasting glucose and 1.04% for fasting C-peptide) was generally comparable to that reported in previous studies In summary, our findings provide no strong evidence to support an association between hyperglycaemia and colorectal cancer among Asian populations; however, a possible association between insulin resistance and colorectal cancer warrants further study with a larger sample size.Supplementary Information.


In past Ecological Momentary Assessment (EMA) studies, hearing aid outcome ratings have often been close to ceiling.To analyze the underlying reasons for the very positive ratings, we conducted a study with 17 experienced hearing aid wearers who were fitted with study hearing aids. The acceptable noise level and the noise level where participants were unable to follow speech were measured. The participants then rated hearing aid satisfaction, speech understanding and listening effort for pre-defined SNRs between −10 and +20 dB SPL in the laboratory. These ratings were compared to ratings of a two-week EMA trial. Additionally, estimates of SNRs were collected from hearing aids during the EMA trial and we assessed whether the participants experienced those SNRs rated poorly in the laboratory in real life.The results showed that for hearing aid satisfaction and speech understanding, the full rating scale was used in the laboratory, while the ratings in real life were strongly skewed towards the positive end of the scale. In the laboratory, SNRs where participants indicated they could not follow the narrator (“unable to follow” noise level) were rated clearly better than the lowest possible ratings. This indicates that very negative ratings may not be applicable in real-life testing. The lower part of the distribution of real-life SNR estimates was related to participants’ individual “unable to follow” noise levels and the SNRs which were rated poorly in the laboratory made up less than 10% of the speech situations experienced in real life.This indicates that people do not seem to frequently experience listening situations at SNRs where they are dissatisfied with their hearing aids and this could be the reason for the overly positive hearing aid outcome ratings in EMA studies. It remains unclear to what extent the scarcity of such situations is due lack of encounters or intentional avoidance. Hearing aid outcomes can be affected by acoustic environments and listening demands that hearing aid users encounter in everyday life. There is a recent wave of Ecological Momentary Assessment (EMA) studies investigating these outcomes in real life [see Holube et al.  for an oAlthough previous EMA studies have been able to show real-life benefits of hearing aid use, the ratings have generally been skewed toward the positive end of the scale . EMA stuNot answering surveys in difficult situations can especially be problematic in cases where a new hearing aid feature that is expected to optimize these infrequently reported listening experiences is evaluated. EMA results that do not capture such situations could lead to wrong conclusions. Also, if two hearing aid programs are compared and difficult situations are modified or in the extreme case avoided due to dissatisfactory hearing aid performance for one program, but not the other, the EMA method could in turn have lower sensitivity to detect a difference between programs. This would be a problem for hearing aid manufacturers evaluating new features, but also when EMA is used in rehabilitation or in the process of choosing and fitting new hearing aids. Hence, understanding whether behavioral adaptations are the underlying reasons behind high hearing aid satisfaction ratings in EMA studies is relevant for development and rehabilitation alike. Collected objective hearing aid data can make such adaptation behavior discernible and might help to judge the suitability of a hearing program for a particular situation.The overarching purpose of the current study was to investigate the reasons behind high hearing aid outcome ratings in EMA studies. To do this, we conducted a combined laboratory and EMA study. We assessed the acceptable noise levels (ANL) as well as hearing aid outcomes at different signal-to-noise ratios (SNRs) rated on EMA scales in the laboratory. We then compared how these laboratory ratings relate to real-life EMA ratings during a 17-day field trial. Our research questions (RQ) were: RQ1: what is the range of the scale ratings in real-life in comparison to the laboratory?; RQ2: how are speech situations at the ANL rated in EMA?; RQ3: what percentage of time during the field trial do participants spend in environments where SNRs are worse than their ANLs or in SNRs that have been rated as dissatisfactory in the laboratory?; and RQ4: are the ANLs measured in the laboratory and the SNRs experienced during the field trial related?Ethical clearance for conducting the study was obtained from the Research Ethics Committee of the Capital Region of Denmark (case no. H-18056647). The participants received written and oral instructions about the aims of the current study. They then signed an informed consent form.Seventeen Danish speaking experienced hearing aid users completed the study  with a median age of 74 years (range: 56–79 years) and median hearing aid experience of 9 years (range: 2–37 years). The participants had moderate-to-severe symmetrical bilateral sensorineural hearing loss . AdditioThe study consisted of two laboratory visits and a 17-day field trial. The laboratory part of the study took place at WS Audiology HQ in Lynge, Denmark. Data collection was done in March 2022 for the first eleven participants and in November 2022 for the remaining six. Each part of the experiment is described in detail below.During the first visit, a new audiogram was obtained if the one on file was older than one year. Participants were then fitted with Signia Pure 312 7X receiver-in-canal (RIC) hearing aids. The hearing aids were fitted to the participant's hearing loss using Connexx (version 9.6.5.182). Own-voice-detection training was performed  the mobile phone is fully charged, (b) hearing aids are functioning as expected, (c) batteries are replaced and (d) a connection between hearing aids and the EMA app can be established. The participants could enable the “Do not disturb” function in the app during time periods where they did not want to be disturbed. Further, the “Do not disturb” function was enabled during participants’ normal sleeping hours for the duration of the study—this time window was individually chosen by each participant to fit their regular sleeping routines.Then, the 14-day EMA period started, where the participants were prompted to answer EMA surveys. The specific EMA questions and response alternatives that were analyzed for this article are outlined in The prompts, meaning the requests to answer a survey, were delivered via an audible notification sound in the hearing aids and a visible notification on the screen of the smartphone. Once a prompt was issued, the notification was visible on the phone screen for 15 min before it disappeared if not answered. The EMA survey timed out 30 min after it was initiated if not completed. Prompts other than speech detection prompts were independent of the Bluetooth connection between hearing aids and the smart phone, but the survey could only be answered if there was a Bluetooth connection, to ensure the acquisition of the corresponding objective data. The objective hearing aid data that were collected are outlined in The study lead could monitor online how many surveys have been answered and when the last Bluetooth connection was established and could follow up with participants if any problems with data collection or participant compliance were detected. Hearing aid usage throughout the trial period was confirmed from the collected data after each participant completed the study.There are no existing audiological rating scales that have been validated for use in EMA, though some studies looked into construct validity , 14 or sFor hearing aid satisfaction, Kerner et al.  and JensIn previous EMA studies several different questions for speech understanding have been used. These comprised the quality of speech understanding  or the aThe question of listening effort is based on the ACALES scale which has been validated in German language in the laboratory . Here thThe above considerations resulted in different numbers of response options for each attribute. However, it is not uncommon in EMA that some, but not all attributes have the same number of response options, as often each question is evaluated in isolation e.g., , 21, 22.Following the field trial, the ANL and a rating test with the EMA app at different SNRs (“SNR test”), were conducted. The ANL and SNR tests were done after the field trial to ensure that participants have gained a stable representation of the rating scale before they did the SNR test. After the test, the participants returned the study equipment.All listening tests were performed in a highly absorbent listening room, isolated with 100 mm rock wool. The dimension of the room was 395 × 285 × 240 cm. Calculated reverberation time (RT60) was below 120 ms in the frequencies 0.125 to 8 kHz. In this room, a setup with eight loudspeakers was used see , where tTwo different speakers  were used in two different noise signals (traffic and canteen noise). The speech materials were taken from audio books, i.e.,  for maleIt has previously been shown that visual cues can significantly lower noise annoyance , hence, The ANL test was administered via an iPad. The test started by measuring the most comfortable level (MCL). The initial speech signal was a female voice in quiet at 60 dB SPL. The participants were instructed to listen to a recording of the speaker telling a story, while adjusting the level of the speech signal in 5 dB steps using an up and down procedure: first, the participant increased the level of speech signal to where it was too loud to listen to, then they decreased the speech level until it became too soft to listen to. Finally, the participant adjusted the speech level to where it was the most comfortable to listen to and this was the measured MCL.Then, the background noise level (BNL) was measured. The participants were instructed to listen to the same female voice telling a story, but this time, with background noise, starting with canteen noise. The participants first increased the background noise level in 5 dB steps to where they could no longer follow the narrator. We term this the high noise level (HNL). Then, they decreased the background noise level in 5 dB steps to where the speech became very clear and distinct. Finally, the participant adjusted the background noise level in 2 dB steps to where they would be willing to listen to the speech-in-noise for an extended period and this was the measured BNL.Two BNLs were measured in the current study: speech level set to individual MCL measured in the first task, and speech level set to 65 dB SPL which corresponds to the level of a conversation in noise . The tesThe ANL was calculated based on the individual MCL and BNL values (ANL = MCL–BNL) . As we wThe participants were asked to rate their satisfaction with hearing aids, speech understanding and listening effort while listening to speech-in-noise at different SNRs. They used the EMA app with the same questions and response alternatives for the three attributes as done during the field trial see . It shouThe speech signal was fixed at 65 dB SPL and the SNR varied between −10 and 20 dB SPL in 5 dB steps. Each of the four stimulus combinations  were presented seven times in random order. The participants indicated when they were done rating the sound file they were listening to by raising their hand, after which the study lead played the next sound file. Both the SNR test as well as the ANL test were performed with hearing aids on.As questions on speech understanding and listening effort were situation dependent, surveys were counted as completed if the first four questions enquiring about hearing aid satisfaction, listening environment, listening situation and background sounds were answered. Sampling rate for the objective data varied with stability of the connection. To get an assessment of the amount of collected objective data, we looked at each individual minute and counted all the minutes where at least one data point was collected. Unless otherwise noted, the SNR estimates from the hearing aids were analyzed only for situations that were classified as “Speech in Noise” or “Speech in Quiet”. Also, only situations where own voice of the hearing aid wearer was not detected were taken into account. The ANL test speech levels and background levels should follow a certain pattern, i.e., first high, then low and then in-between. Data from three participants deviated from this pattern by more than 3 dB in some of the trials. Hence it was assumed that instructions were not correctly followed and the complete data from these participants were discarded in all the analyses that included the ANL test.For correlation analysis between real-life SNRs and ANL or UNL, it would be desirable to pool the results from the trials with different speakers and noise types to reduce potential noise in each single trial. To ensure that there were no significant differences between trials before pooling, two repeated measures one-way ANOVAs with speaker and noise type as independent variables were performed. Dependent variables were ANL and UNL, respectively.p-value in the results section. All the statistical analyses were done in MATLAB 2019b.Data analyses were mostly descriptive using boxplots or means with 95% confidence intervals. All error bars denote 95% confidence intervals obtained via bootstrapping with 50,000 repetitions. Bootstrapping was used as data distributions for some SNRs and ratings in the field trial were asymmetric. In cases where statistical inference tests were used, they are reported together with the As values of SNR estimates collected by the hearing aid during the laboratory tests did not exactly match the SNRs measured there, the hearing aid SNR estimates were mapped to the laboratory SNR values for determining the percentage of SNR estimates below the ANL and UNL.p = 0.71). Similarly, there was no significant difference between UNLs . Collapsing across conditions, the group means for ANL and UNL were 11.0 dB SNR (SD: 5.8 dB SNR) and 2.2 dB SNR (SD: 6.2 dB SNR), respectively. To get a sense of the consistency of the ANLs and UNLs, mean absolute differences between measures for traffic and canteen noise were computed and averaged across participants. In addition, Pearson correlation analyses between the measures were done. Generally, the mean absolute difference was below 5 dB and all the compared measures except the UNL for individual MCLs (p = 0.07) were significantly correlated (p < 0.01). ANLs for individual conditions as well as MCLs for each participant can be found in the On a group level, no significant difference was found between ANLs with different background noise types and between the conditions where speech level was fixed and those where participants could choose their MCL  of which 98 (range: 22–194), that is 60%, were reported to be in speech situations and hence contained questions on speech understanding and listening effort. The median survey completion time for each participant was on average 39 s (range: 20–100 s).Collected objective data points per participants were on average 47,482 . On average 83.4 h (range: 31.9–147.4 h) of objective data were collected per participant (counting each minute where at least one data point was collected as described in the methods section). For the full duration of the study the average total hearing aid wearing time was 247.3 h (range: 174.8–342.1 h). This includes the acclimatization time, except for one participant for whom no data were collected during the acclimatization time due to a technical error. Daily wearing time was on average 13.6 h (range: 7.1–16.3 h). Speech was detected by the hearing aid on average 27% (SD: 12%) of the wearing time.t-test, p > 0.2 for all three attributes).The EMA ratings for hearing aid satisfaction, speech understanding and listening effort are shown in We analyzed how commonly the SNRs rated poorly  in the laboratory  occur inOf the collected SNR data during the field trial, the median percentage below the mean UNL across all conditions was 13.1% (SD: 9.7%). Mean percentage below the ANL was 32.0% (SD: 18.6%), see also We conducted correlation analysis between individual ANLs and the real-life SNR estimates to assess whether there is a relationship between the two measures. It could be that there are only few situations with SNRs below ANL or UNL because those situations simply do not occur in the participants' environment. However, if correlation exists, it could be indicative of each person having some control to shape his or her environment to their needs.r = 0.18, p = 0.54). When doing the same analysis with the UNL, there was a moderate correlation  did not differ on the group level, the four types of ANL were averaged for the correlation analysis. If the ANL is indicative of which SNRs are not experienced in real life, it should correlate with the lowest SNRs experienced in the field trial. Hence, the 5th percentile of the real-life SNR estimates was included in the correlation analysis. No significant correlation between experienced SNR and measured ANL was found  of SNRs during the field trial were below the ANL measured in the laboratory and even less (13%) below the UNL. At 11.0 dB SPL, the mean ANL measured here was slightly lower than previously measured ANLs in Danish normal hearing individuals [e.g., : 12.6–16% of SNRsThe SNRs in the laboratory test corresponding to ANLs were generally still rated very positively . Even thThere are fundamental differences between laboratory experiments and EMA. In laboratory experiments, participants can be asked to pay attention to speech signals that are incomprehensible and hence the very negative response alternatives can be used. In real life, participants would be very unlikely to endure such situations and then the very negative response options may not be relevant. As such, it may be appropriate to use different rating scales for EMA and laboratory experiments. It has previously been discussed that unipolar and bipolar scales substantially differ with respect to measurement properties . BipolarOur results showing a limited number of real-life situations with unfavorable SNRs during the field trial are in agreement with Smeds et al.  and Wu eSmeds et al.  analyzedLooking at the SNR of different noise categories in Smeds et al. , only thThe question is what the underlying reasons for the rare occurrence of unfavorable SNRs are. There are very few situations where humans have no control over the noise level . Some situations are controlled by the society  and some situations an individual has control over. Even if the noise cannot be changed, individuals have the choice to abort a conversation or continue it elsewhere. However, there may be consequential reasons for not doing this. For example, if work colleagues go to a very noisy canteen every day and it is important to the individual to spend time with them, one may decide to endure the noisy canteen from time to time.1 showing varying modifications, acoustic environments and wearing behaviour depending on the hearing aid program used throughout the day. If individuals avoid or modify certain situations based on insufficient hearing aid performance, this has implications for EMA beyond the use of rating scales. In particular, hearing aid performance may be overestimated and sensitivity when comparing different hearing devices or programs may be reduced. When different conditions are compared, collection of objective data in addition to EMA can make differences in avoidance or modification behaviour discernable. Hence, whenever possible, the objective data should be collected in addition to subjective ratings when looking for these effects. Potentially, the objective data can even showcase adaptation of situations based on hearing aid performance without subjective ratings, and as such, could be an inobtrusive way to collect information about preferences of hearing aid features or programs.The ANL by instruction indicates which SNRs participants are willing to listen to for a long time and the UNL at which SNRs they cannot follow the narrator anymore. Hence, presumably they would try to reduce the amount of listening situations at SNRs below the ANL and even more so below the UNL. Our hypothesis that the ability of individuals to adapt listening situations to their needs would lead to correlations between the ANL and lesser experienced low SNRs did not hold. However, there was a moderate correlation between the UNL and the 5th percentile of the experienced SNRs. This correlation to an extent supports the hypothesis that difficult situations may be avoided / modified. Avoidance or modification of difficult situations is in line with an EMA study by Schinkel-Bielefeld  showing It should also be noted that a potential driver of correlation between UNLs and real-life SNRs could be that the acoustic environments participants experience in everyday life shape their ANLs and UNLs. For example, if one spends most time in quiet environments, not necessarily due to purposeful avoidance because of discomfort / hearing difficulty, one's sensitivity to noise in turn may be higher. Similarly, if one spends a lot of time in noisy environments, one's sensitivity to noise may be lower. Whether it is the UNLs that guide the types of environments one spends time in, or whether it is one's everyday environments that determine their UNLs cannot be disentangled from the current data.As most EMA studies in audiology, this study was conducted with a small sample size and should be verified by a larger study.Also, several limitations of the novel UNL measure should be noted. Originally this was just meant to be a reversal point in the ANL procedure determined with a larger step size than the final ANL value. However, communication to the participants did not treat it as any less important than the end point of the ANL test. Hence, presumably participants used the same care for both measurements. The novel UNL measure has not yet been validated. Here it is assumed that the SNR where one cannot follow a conversation is similar to the SNR where participants start changing their behavior to improve the SNR. This assumption needs testing. Additionally, a new measure directly addressing unacceptability of the SNR and avoidance / modification behavior may lead to greater correlations with real-life SNRs, though this would also require validation. The fact that three participants did not follow instructions suggests that the ANL would have benefitted from training.Collection of the SNRs was dependent upon participants carrying the research phone with them and reconnection between hearing aids and research phone when hearing aids were within reach of the phone was not always successful. It could, however, be fixed by restarting the phone. For this reason, only about a third of the objective data were collected. However, technical reconnection problems were independent of the acoustic situation and should not affect the representativeness of the collected data. As participants may be less likely to interact with the research phone in social situations, there may be an underestimation of those situations . Also, dAutomatic estimation of SNRs by hearing aids is difficult. Even if the SNR is estimated accurately, there is no way of knowing whether the hearing aid wearer is paying attention to the estimated target signal  or not. Further, SNR estimation accuracy decreases for low SNRs and as such low SNRs may be underestimated. The difficulty of a listening situation does not only depend on the SNR, but on many other factors. While a lower SNR can cause greater listening effort, a familiar person talking slowly with clear articulation about a known topic is easier to understand than an unfamiliar voice with a heavy accent talking rapidly about an unknown topic. All those influences were not captured in the current study.The results showed that the full rating scale was used in the laboratory, while the ratings in real life were strongly skewed towards the positive end of the response scales. Hence, reluctance to give negative feedback is likely not an underlying reason for the positive ratings in real life. The UNL, meaning the SNR where participants could not follow the speech anymore, was rated at the mid-point of the speech understanding scale and at “more or less satisfied” on the hearing aid satisfaction scale. This questions how relevant the lower part of the rating scales used in this study is for rating real-life situations. The hearing aid data collected during the EMA trial were related to participants' UNL. These data also indicated that people do not seem to frequently experience listening situations at SNRs where they are dissatisfied with their hearing aids. This could be the reason for the overly positive hearing aid satisfaction ratings in EMA studies. It remains unclear to what extent the scarcity of such situations is due lack of encounters or adaptation of the acoustic environment in dissatisfactory situations.


Nowadays, cochlear implant (CI) patients mostly show good to very good speech comprehension in quiet, but there are known problems with communication in everyday noisy situations. There is thus a need for ecologically valid measurements of speech comprehension in real-life listening situations for hearing-impaired patients. The additional methodological effort must be balanced with clinical human and spatial resources. This study investigates possible simplifications of a complex measurement setup.The study included 20 adults from long-term follow-up after CI fitting with postlingual onset of hearing impairment. The complexity of the investigated listening situations was influenced by changing the spatiality of the noise sources and the temporal characteristics of the noise. To compare different measurement setups, speech reception thresholds (SRT) were measured unilaterally with different CI processors and settings. Ten normal-hearing subjects served as reference.2 = 0.69. For conditions with stationary interfering signals, R2 values <0.2 were found.In a complex listening situation with four loudspeakers, differences in SRT from CI subjects to the control group of up to 8 dB were found. For CI subjects, this SRT correlated with the situation with frontal speech signal and fluctuating interference signal from the side with RThere is no universal solution for all audiometric questions with respect to the spatiality and temporal characteristics of noise sources. In the investigated context, simplification of the complex spatial audiometric setting while using fluctuating competing signals was possible. In the clinical care of hearing-impaired patients with hearing systems, there is a need for measurements of speech comprehension—especially in follow-up—that cover various aspects of everyday use. By means of audiometric examinations in the clinic or practice, a realistic model of typical daily communication situations is created. The results obtained in this way can be used for the adequate assessment of the hearing deficiencies resulting from various hearing pathologies. Important characteristics of everyday listening situations include fluent speech presentation, multimodal stimuli, realistic speech levels, spatial separation of signal and noise sources, reverberation and the occurrence of direct and reflected sound, i.e., competing noise, and the acoustic characteristics of different speakers , 25, 41.Patients with a severe degree of hearing loss who can no longer achieve sufficient speech comprehension with a hearing aid have the option of (re)gaining hearing through a cochlear implant (CI). After this surgical therapy, speech understanding must be checked regularly. This serves to characterize the hearing handicap relevant to everyday life in order to optimize understanding in the future. It is generally accepted that speech understanding in quiet and in noise provides suitable surrogate parameters for describing the ability to communicate in everyday life , 28.The inventory of methods available for this purpose consists of established examination methods such as the Freiburg Monosyllabic Word Test in quiet , 22, 23.Certain supplementary investigations appear to be especially suitable for answering particular questions regarding speech comprehension in competing noise , 41. HerFurther developments in CI processor technology have improved speech intelligibility in noisy environments , 17, 30.In the present study we investigated whether, and to what extent, such complex listening situations may be simplified to measure speech comprehension in noise. This simplification is to be considered in two dimensions. For this purpose, different temporal characteristics of the noise were chosen, with stationary speech-simulating Oldenburg noise compared with fluctuating ICRA noise. Also, simplified spatial arrangements of the noise source(s) were investigated, using load speaker constellations with two or only one signal source compared with the reference configuration with four speakers. The results for speech reception threshold (SRTs), measured with the Oldenburg Sentence Test (OLSA), are compared in different audiometric settings and evaluated with respect to their equivalence. In addition, the use of two generations of speech processors was investigated, to determine the extent to which the technical development of these can contribute to improved speech understanding in these complex listening situations.A group of 20 CI patients with postlingual deafness participated in this study. The study was approved by the local ethics committee (D 06/18). All examinations were conducted in accordance with the ethical standards of the Institutional and National Research Commission and the 1964 Declaration of Helsinki and its subsequent amendments, or with comparable ethical standards.SPL). Bilateral implantation was not an exclusion criterion, but only one ear per patient was examined in this study. In 17 patients all 22 electrodes were activated, in three cases 21 electrodes were active.The inclusion criteria for the adult participants in the study were postlingual onset of hearing loss and use of a CI24RE or CI5xx cochlear implant  with full insertion of the electrode array into the scale tympani. Participants were to achieve a speech understanding of at least 80% at the initial examination using the OLSA in quiet . Participants had a mean CI experience of 8.3 years . The biographical details of the participants have been published elsewhere  In the field of acoustics, audiometry has today developed into a fine, indeed the very finest, diagnostic instrument. Even the correct handling of pure-tone audiometry requires knowledge and a lot of practical experience. The situation is somewhat more complicated with speech audiometry, which on the one hand has the advantage that it can be used to measure the entirety of the hearing of complex sounds, but on the other hand has the difficulties of a measuring method the results of which are influenced by a large number of factors. Despite the greater expense of equipment and expertise, this method is indispensable today both for the assessment of hearing ability in general and of changes in hearing caused by therapeutic interventions—in particular, for the fitting of hearing aids” (translated from ). This qIn the diagnosis of hearing disorders that accompanies therapy, there is no universal solution for all audiometric questions.In addition to the established standard procedures such as the Freiburg Monosyllabic Word Test and the sentence tests in stationary noise used in German-speaking countries, new tests adapted to the special questions and therapeutic procedures are necessary.A complex audiometric setting for speech understanding, consisting of four loudspeakers with a fluctuating masker in the posterior hemisphere, can be reduced to two loudspeakers while retaining the fluctuating masker; this leads to comparable audiometric results in the context studied here.


Otoplan is a surgical planning software designed to assist with cochlear implant surgery. One of its outputs is a recommendation of electrode array type based on imaging parameters. In this retrospective study, we evaluated the differences in auditory outcomes between patients who were implanted with arrays corresponding to those recommended by the Otoplan software versus those in which the array selection differed from the Otoplan recommendation. Pre-operative CT images from 114 patients were imported into the software, and array recommendations were generated. These were compared to the arrays which had actually been implanted during surgery, both in terms of array type and length. As recommended, 47% of patients received the same array, 34% received a shorter array, and 18% received a longer array. For reasons relating to structure and hearing preservation, 83% received the more flexible arrays. Those who received stiffer arrays had cochlear malformations or ossification. A negative, although non-statistically significant correlation was observed between the CNC scores at 12 months and the absolute value of the difference between recommended array and implanted array. In conclusion, clinicians may be slightly biased toward shorter electrode arrays due to their perceived greater ability to achieve full insertion. Using 3D imaging during the pre-operative planning may improve clinicians’ confidence to implant longer electrode arrays, where appropriate, to achieve optimum hearing outcomes. Cochlear implantation is the current gold standard treatment for severe-to-profound sensorineural hearing loss. A cochlear implant (CI) operates by directly stimulating the auditory nerve via an electrode array inserted into the cochlea. Given the tonotopic organisation of the cochlea, it is considered important that the electrode array length corresponds to the cochlear duct length (CDL) to enable the entire cochlea to be stimulated ,2,3. It Arrays that are short relative to the CDL can have a detrimental impact on the users’ hearing outcomes, leading to reduced performance in speech understanding tests ,9,10. OnThe methods used to estimate the CDL have evolved over time. The first method involved measuring the organ of Corti using histological sections with a micrometre . This teIn 2018, an otological planning software was developed for robotic CI implantation. The software can estimate the CDL and the corresponding frequency map, as well visualising the projected location and coverage of different array types [This software has been validated as a useful and reliable tool for estimating CDL, angular insertion depth (AID), and frequency mapping ,20, and clinician-based choice of an electrode array differs from the 3D-imaging-based choice for a specific electrode array length and the respective outcomes. The secondary aim of the study was to evaluate if the auditory performance differed between cases where the selected electrode was or was not in agreement with the 3D-imaging-based choice in terms of array length.The primary aim of this study was to evaluate to what extent the For this retrospective study, we examined records of patients with bilateral hearing loss (BiHL) or single-sided deafness (SSD) who had received a MED-EL CI  at a tertiary hospital in Western Australia between 2013 and 2020. Participants were included in the study if they were unilateral or bilateral CI users, had profound sensorineural hearing loss of any aetiology and duration, and had had high-resolution CT scans of the temporal bones as part of the pre-operative planning. Participants were excluded if their pre-operative CT images were not available at the time of review. The following information was obtained from the participants’ medical records: demographic information, the type of electrode array implanted, the reason for array selection (if documented), and pre- and post-operative audiometric test results. This study was designed and conducted in accordance with the Declaration of Helsinki, and ethical approval was obtained from the South Metropolitan Area Health Service Human Research Ethics Committee, Australia.0N0), speech from the front and noise from the hearing ear (S0NHE), and speech from the CI side and noise from the hearing ear (SCINHE). The Bamford–Kowal–Bench speech-in-noise (BKB-SIN) test was used with an adaptive procedure to measure the signal-to-noise ratio required to achieve an intelligibility score of 50% (SRT50).Speech perception tests were conducted in quiet and in noise in a soundproof booth with the loudspeakers placed at ear level, 1 m from the centre of the subject’s head. For participants with BiHL, aided speech perception was tested in quiet using the consonant–nucleus–consonant (CNC) test, with the stimuli presented at 65 dB SPL. Pre-operative aided testing was performed using a hearing aid and post-operative testing was conducted using a CI. Participants with SSD underwent a speech perception in noise test under three spatial configurations: speech and noise presented from the front . The 3D imaging software estimated the AID and frequency that would be reached by the selected array. This electrode array selection is referred to throughout the manuscript as the 3D-imaging-based choice, whilst the implanted electrode array is referred to as the clinician-based choice.Pre-operative CT images were imported from the hospital’s picture archiving and communication system into the OTOPLAN software  to create a 3D reconstruction of the cochleae. A clinician then manually marked key anatomical cochlear structures such as the modiolus, round window, apical, and basal turns. A single clinician marked all scans in order to avoid any inter-evaluator variability. These marks are used by the software to automatically calculate cochlear diameter, width, height, and CDL. Based on the measurements and visualisation of the CDL in relation to the audiogram, the clinician selected one of the FLEX electrodes arrays that would be the best fit for the given cochlea. The following electrode arrays for selection were as follows: FLEXThe AID and frequency at the most apical electrode contact (C1) were also calculated for the implanted array in the 3D imaging software. The data were exported into a Microsoft Excel file.3D-imaging-based choice, a group that received a shorter array, and a group that received a longer array. The Kruskal–Wallis H-test was used to assess the difference in performance between the three groups at different time points (pre- and post-operatively). The Mann–Whitney U-test was used for pairwise group comparisons. Results were considered statistically significant at p values < 0.05.The data were analysed in IBM SPSS Statistics Version 24 . Descriptive summary statistics including mean, median, standard deviation and range, were calculated for demographic, electrode array, and speech test data. Speech test data were divided into three subgroups: a group that received an electrode array that coincided with the A total of 114 adult unilateral CI users were included in this study with 66 (57.9%) being male, and 48 (42.1%) being female. Of these, 49 (43.0%) had SSD and 65 (57.0%) had BiHL whilst 67 (58.8%) had a CI on the right ear and 47 (41.2%) on the left ear. In the SSD group, the mean time since the onset of hearing loss was 10.0 years (range: 0.1–41.0 years) and the mean age at implantation was 50.5 years (range: 1.3–79.4 years). In the BiHL group, the mean time since the onset of hearing loss was 2.2 years (range: 0.04–8.0 years), the mean age at implantation was 61.4 years (range: 18.4–85.0 years), and the mean time since implantation was 5.3 years (range: 0.8–11.7 years).28, the second-longest implanted array, was both the most commonly recommended (47.4%) and the most commonly implanted (65.8%). FLEXsoft, the longest implanted array, was also commonly recommended using the 3D imaging software (42.1%), although it was implanted in only 5.3% of cases. The numbers of implanted and recommended electrode arrays of each type are given in Of the participants, 54 (47.4%) received the same electrode array as was recommended by the 3D imaging software, while 39 (34.2%) received a shorter electrode array and 21 (18.4%) received a longer electrode array. FLEXWe reviewed the clinical case notes recorded at the time of insertion to determine the reasons the implanting surgeon chose the electrode. Longer electrode arrays were implanted for one of the following three reasons: (1) to provide a possible wider range of electrical stimulation if any residual hearing deteriorates over time, (2) due to the range of electrode arrays available at the time of surgery, or (3) due to the surgeon’s preference for a deeper insertion. Shorter electrode arrays were implanted for one of two reasons: (1) due to the surgeon’s preference for a shorter electrode array, and (2) due to the presence of cochlear abnormalities such as ossification or fibrosis.24, FLEX26, FLEX28, or FLEXsoft) whereas, the remaining 19 (16.7%) received a stiffer electrode array , or STANDARD (31.5 mm)).Of the participants, 95 (83.3%) received a soft electrode array from the FLEX series , obtained using the 3D imaging software, were compared with the actual values obtained post-operatively . The prep = 0.2).The BiHL group underwent CNC word tests pre- and post-operatively. Subgroup averages were calculated separately for those who received the same arrays, longer arrays, and shorter arrays . The Kru0N0, S0NHE, SCINHE) pre- and post-operatively (The SSD group underwent speech-in-noise tests (Sratively . Subgrouratively . The Kru3D-imaging-base choice) and the electrode arrays chosen by clinicians at the time of surgery (clinician-based choice). The secondary aim was to determine if there was a difference in the auditory performance of patients who had an implanted array that was the same length as, shorter, or longer than the 3D-imaging-based choice.The primary aim of this study was to retrospectively compare the differences between the arrays recommended using the 3D imaging measurement based on pre-operative CT images  than a longer (18%) electrode array relative to the 3D-imaging-based choice. This result suggests that clinicians tend to favour selecting the electrode arrays that would, in their opinion, be most likely to fit the majority of cochleae irrespective of their CDL. For example, 30 (34%) participants could have received the longest FLEXsoft array (31.5 mm) but instead received the FLEX28 (28 mm) array. In this group, CNC scores at 12 months were lower compared to those that were implanted with longer arrays. It is possible that if the 3D imaging software had been used during pre-operative planning, a longer array could have been recommended and implanted. When clinicians implanted an array longer than that recommended, the cited reasons were either electrode array availability at the time of surgery, or concerns about long-term hearing outcomes when using a shorter array if residual hearing deteriorated.Our findings indicate that, out of 114 implanted arrays, 47% matched the The choice of electrode array by most clinicians is typically informed by the evidence that longer arrays are associated with better auditory performance, but worse hearing preservation ,26. ThisIn our study, arrays differed not only in length, but also in stiffness. We included three electrode array families: FLEX, FORM, and CLASSIC. FLEX arrays are soft, flexible, and have a thinned tip. These features are designed to make cochlear implantation as atraumatic as possible, with the aim of maximising hearing preservation. FORM and CLASSIC (STANDARD and MEDIUM) arrays are stiffer than FLEX arrays and are designed specifically for malformed or ossified cochleae. In our study, 83% of participants received a FLEX array. Stiffer arrays were only implanted in malformed or ossified cochleae, in accordance with the manufacturer’s guidelines. This distribution of array selections suggests that in our centre, when selecting from a range of electrode arrays, clinicians preferred a less traumatic array for structure and hearing preservation and that, in the majority of patients with normal cochlear anatomy, it is not necessary to utilise stiff arrays .3D-imaging-based choice, 36.2 mm in the group that received shorter arrays, and 33.5 mm in the group that received longer arrays. These mean values correspond to the higher end of the CDL range reported in the literature [3D-imaging-based choice; the opposite was true for shorter arrays. This suggests that the length of the electrode array has a measurable effect on the place pitch matching. This contrasts with the previously held idea that a one-size-fits-all approach to electrode array selection is sufficient.The mean CDL was 34.4 mm in the group that received the same arrays of the same length as the 3D-imaging-based choice for array selection has an effect on post-operative speech outcomes. A negative Pearson correlation (−0.23) was observed between speech-in-quiet scores at 12 months and the absolute value of the difference between the recommended array and implanted array, but this did not rise to the level of statistical significance (p = 0.2). This finding contrasts with those of previous studies that measured speech performance as a function of cochlear place-to-frequency mismatch, analogous to the use of shorter or longer arrays than appropriate for a given CDL. Mertens et al. [We attempted to ascertain whether diverging from the s et al.  reporteds et al. ,32 similRelative to the previous studies, our study analysed speech perception at a later timepoint (12 months). This may plausibly explain the divergence between our findings and those of the previous studies. It is possible that neuroplastic effects may allow the user to gradually accommodate to a frequency–place mismatch, eventually reaching speech perception abilities equivalent to those of users without a mismatch. It nevertheless remains the case that the presence of a mismatch deprives the user of optimal hearing outcomes for a duration of several months post-activation. This is undesirable in and of itself, even if the deficit resolves over time. Furthermore, such deprivation might leave subtle long-term or permanent deficits that are not revealed by simple speech-in-quiet or speech-in-noise testing.As noted, cochlear anatomy and residual hearing can vary greatly between individuals. Variation in CDL, anatomical anomalies, and the proportion of surviving hair cells means that one size cannot simply fit all. Specialised arrays of different length and stiffness can ensure both full insertion and complete coverage of the cochlear duct in all types of cochleae. The technique known as 3D imaging is designed to facilitate electrode array selection based on individual cochleae parameters and is gradually gaining validity in CI surgery planning ,22,24,25Limitations of this study: it is important to note that our study was not powered to reliably assess the association between array choice and auditory outcomes, so our results are preliminary, and analysis of larger test groups is required. Additionally, the retrospective nature of this study is an important limitation, and it would be interesting to replicate these findings in a prospective multi-centre design, controlling for other variables that could have enhanced the difference between the groups.Clinicians preferred an electrode array that differed from the 3D imaging software recommendation in approximately 50% of cases. Shorter and more flexible arrays were favoured for their perceived benefits in structure and hearing preservation. Routine 3D imaging software use would lead to greater longer electrode implantation, with the potential to achieve better hearing outcomes.