We use ~92-s datasets of proton plasma moments , measured from the Solar Wind Experiment instrument onboard Wind spacecraft, to estimate the moving averages of the polytropic index, as well as their weighted means and standard errors as a function of the solar wind speed and the year of measurements. The derived long-term behavior of the polytropic index agrees with the results of other previous methods. In particular, we find that the polytropic index remains quasi-constant with respect to the plasma flow speed, in agreement with earlier analyses of solar wind plasma. It is shown that most of the fluctuations of the polytropic index appear in the fast solar wind. The polytropic index remains quasi-constant, despite the frequent entropic variations. Therefore, on an annual basis, the polytropic index of the solar wind proton plasma near ~1 AU can be considered independent of the plasma flow speed. The estimated all-year weighted mean and its standard error is  Each polytropic relationship indicates a family of streamlines of the fluid or plasma flow. The functional form is, typically, a power-law between two thermodynamic variables, that is, γ indicates the polytropic index; ν denotes an alternative polytropic index, which defines the effective degrees of freedom κ0 [γ (or ν) is the same for all the streamlines characterizing the thermodynamic process  becomes the 2-D space of . They can be substituted by the thermodynamic values at a certain point on the streamline, e.g., γ → −∞, and moving with increasing γ, we have the processes of isobaric for γ → 0, isothermal for γ → 1, adiabatic for γ → 5/3, and isochoric again for γ → +∞. The four intervals in between correspond to “Explosion” for −∞ < γ < 0, “Mild Explosion” for 0 < γ < 1, “Sub-adiabatic” for 1 < γ < 5/3, and “Super-adiabatic” for 5/3 < γ < +∞  Solar wind has strong fluctuations in magnetic pressure, and plasma beta ; however, the definition and calculation of the polytropic index involves only the thermal pressure =A⋅ndeff [κ0 ,4, that deff [κ0 , Chaptereference ), the queference ,8). Noteferences ,10). .γ < 5/3), e.g., Totten et al. [https://omniweb.gsfc.nasa.gov/) to calculate the polytropic indices of solar wind protons, and found that the distribution of polytropic indices is a κ-Gaussian distribution with mean ≈1.8 and standard error of the mean ≈2.4.Nevertheless, the solar wind protons near 1 AU exhibits polytropes with sub-adiabatic indices  for the solar wind proton plasma near Earth (~1 AU). The paper is organized as follows. In Vsw, density n, and temperature T), e.g., References [https://wind.nasa.gov/data.php), or at the OMNIWeb-Plus database, which includes the solar wind phase only (https://omniweb.gsfc.nasa.gov/ftpbrowser/wind_swe_2m.html). We repeated our calculations for all the years in the period 1995–2017, spanning the two solar cycles 23 and 24  data of solar wind proton plasma moments th data points, to derive the polytropic index at the ith data point given by:ith and (i + 1)th data points correspond to invariant Bernoulli integral, in order to reduce the possibility of streamline crossing [We used the density ata, see ). Note: crossing ,23.M-step moving average is given by (according to Reference [The eference ):(4a)γ¯:(4c)ferences ,37,38,39γ and its moving average Mγ for step M = 1–5, and their errors. We constructed the time-series for Mγ, for M = 1, 3, 5, for the first 70 days of 1995, plotted in M = 1 corresponds to the raw time series of γ values).Using Equations (3a) and (3b) and Equations (4a)–(4d), we derived the polytropic index Vsw, Mγ) for M = 5 moving averages to the data from M stabilizes the 2D-histogram, as it does in this case for M = 5. We normalized the 2D-histograms to investigate the actual relationship between γ and VSW. VSW, which clearly demonstrates that the distribution of polytropic indices has weak dependence of the solar wind speed, at least for the year 1995.We, then, constructed the normalized 2D-histograms of .Here, we estimated the average values and errors of the polytropic indices. In particular, we first determined the polytropic indices that characterized the solar wind plasma observed over two solar activity cycles at 1 AU. Namely, we generated the datasets of polytropic index for the raw data of the yearly time-series (1995–2017). Then, we estimated the weighted means and errors for each bin of the solar wind speed and for each year (1995–2017).Vsw > 550 km/s .γ ≈ 1.46; when the magnetic pressure was also included  they found γ ≈ 1.58. For the year 1995, we find γ ≈ 1.69 ± 0.03 . What is most important to mention is that Reference [This quasi-constancy of the solar wind polytropes to the plasma flow speed agrees with the results of Totten et al. . These a9 ± 0.03 , while f3 ± 0.05 . . We alsγ = 1.86 ± 0.09 (shown in the figure within the transparent red rectangular), corresponding to 2.3 effective degrees of freedom (super-adiabatic process). This derived long-term value of the polytropic index agrees with the results of Reference [eference .Vsw > 550 km/s. This becomes clearer in N = 50 is the number of plasma flow speed bins. The reduced chi-square values, taken for plasma flow speed Vsw = 550 km/s for each year, is shown in As we mentioned, the polytropic index appears to fluctuate and departs from the quasi-constancy mostly in the fast solar wind, i.e., typically for The above results suggest that it is rather more possible for high velocities of the solar wind plasma to develop intermittent turbulent states . In addiVsw, density n, and temperature T), measured from the SWE instrument onboard Wind S/C.We derived the polytropic indices over the last two solar cycles (years 1995–2017) for the solar wind proton plasma near Earth (~1 AU), using high-resolution ~92-s datasets of proton plasma moments (speed The polytropic index was estimated for five point moving averages. We constructed the time series of the derived polytropic indices, as well as their weighted means and standard errors per selected bin of the solar wind speed and per year. The derived long-term behavior of the polytropic index agrees with the results of other previous methods.The polytropic index remains quasi-constant with respect to the plasma flow speed. This result agrees with the results of previous analyses of solar wind plasma, even for smaller heliocentric distances.The polytropic index remains quasi-constant, despite the frequent entropic variations.Most of the fluctuations of the polytropic index appear in the fast solar wind.γ = 1.86 ± 0.09.The estimated all-year weighted mean and its standard error is The main results are summarized as follows:Therefore, on an annual basis, the polytropic index of the solar wind proton plasma near ~1 AU can be considered independent of the plasma flow speed.


Hearing Loss (HL) is common among older adults and is associated with poor health care quality outcomes include 30-day readmissions, length of stay, poorer satisfaction, and increased medical expenditures. These associations may manifest in changes in help-seeking behaviour. In the 2015 Current Medicare Beneficiary Study (MCBS) , participants reported whether they knowingly had avoided seeking care in the past year and self-reported HL was measured as degree of trouble  hearing when using a hearing aid if applicable. In a model adjusted for demographic, socioeconomic, and health factors, those with a little trouble  and a lot of trouble hearing  had 61.2% and 101.1% higher odds of avoiding health care over the past year relative to participants with no trouble hearing. Future work should examine whether hearing care modifies this association.


Ubiquitination is a dynamic post-translational modification that regulates the fate of proteins and therefore modulates a myriad of cellular functions. At the last step of this sophisticated enzymatic cascade, E3 ubiquitin ligases selectively direct ubiquitin attachment to specific substrates. Altogether, the ∼800 distinct E3 ligases, combined to the exquisite variety of ubiquitin chains and types that can be formed at multiple sites on thousands of different substrates confer to ubiquitination versatility and infinite possibilities to control biological functions. E3 ubiquitin ligases have been shown to regulate behaviors of proteins, from their activation, trafficking, subcellular distribution, interaction with other proteins, to their final degradation. Largely known for tagging proteins for their degradation by the proteasome, E3 ligases also direct ubiquitinated proteins and more largely cellular content  to destruction by autophagy. This multi-step machinery involves the creation of double membrane autophagosomes in which engulfed material is degraded after fusion with lysosomes. Cooperating in sustaining homeostasis, actors of ubiquitination, proteasome and autophagy pathways are impaired or mutated in wide range of human diseases. From initial discovery of pathogenic mutations in the E3 ligase encoding for E6-AP in Angelman syndrome and Parkin in juvenile forms of Parkinson disease, the number of E3 ligases identified as causal gene for neurological diseases has considerably increased within the last years. In this review, we provide an overview of these diseases, by classifying the E3 ubiquitin ligase types and categorizing the neurological signs. We focus on the Gigaxonin-E3 ligase, mutated in giant axonal neuropathy and present a comprehensive analysis of the spectrum of mutations and the recent biological models that permitted to uncover novel mechanisms of action. Then, we discuss the common functions shared by Gigaxonin and the other E3 ligases in cytoskeleton architecture, cell signaling and autophagy. In particular, we emphasize their pivotal roles in controlling multiple steps of the autophagy pathway. In light of the various targets and extending functions sustained by a single E3 ligase, we finally discuss the challenge in understanding the complex pathological cascade underlying disease and in designing therapeutic approaches that can apprehend this complexity. E3 ubiquitin ligases constitute a large family of enzymes that play pivotal roles in protein ubiquitination, a major posttranslational modification regulating various cellular functions, as diverse as DNA repair, proliferation, apoptosis, transcription, circadian clock, endocytosis, cell signaling, immunity, and protein quality control . UbiquitConferring substrate specificity for ubiquitination, E3 ligases are key in regulating protein activation, function, and degradation. There are classified into three major groups: the HECT (homologous to E6-AP carboxyl terminus), the RING  and the RING-HECT hybrid E3s . The HECGiant axonal neuropathy  is a rare neurodegenerative disease with an autosomic and recessive mode of inheritance . This reGAN gene was discovery through a two steps process, comprising genetic mapping and screening of potential coding sequences within the interval co-segregating with the disease. As for many rare recessively inherited-disease, the genetic localization of the GAN gene was made possible thanks to homozygosity mapping, in consanguineous families that present a higher risk of transmitting mutated alleles. Thus, the GAN locus was delineated within the cytogenetic portion of chromosome 16 in 16q24.1 , others are enriched in given populations , probably as a result of the spreading of common alleles through consanguinity. Several mutations are shared by different countries, that could indicate an ancestral funder effect but could also represent independent mutational “spots”: S79L, R162X, R242X, R269W, P315L, G368R, G474R, E486K, E493K, R545H, R477X, A576E, as well as V7Fs-ins/del, A49E/T, S52G/N, and R545C/H/L. Altogether, these genetic studies have revealed that no major hot spot is found in GAN and that no exon is left intact. As a result, genetic diagnosis for GAN requires the full sequencing of the gene, complemented by cytogenetic analysis for large deletions. In regard to the various phenotypic expression of GAN, which is extremely severe in the vast majority of cases but can exhibit milder forms, assumption is often made to correlate mutation type and position with severity. This is very hazardous, and certainly neither missense, nor position outside the BTB or Kelch domains is synonymous of mild. They are many examples and counter-examples in GAN to show that this is not that simple. Moreover, inter and intra-familial clinical heterogeneity has been evidenced for patients bearing the same mutation , hence sGigaxonin is a 597 amino acid long BTB-Kelch protein  belonging to the Cullin 3-RING (CRL3) subgroup of E3 ubiquitin ligases , 5C. ThiA on various immortalized lymphoblast cells  and 7500 molecules per cell (human lymphoblast cells) . For Gigaxonin, 20 years of research have not quite answered the question. Over 50 monoclonal and polyclonal antibodies have been produced by several laboratories or from commercial sources. With the caution that should be made towards overexpression system, ectopic Gigaxonin produces a wide range of granular staining depending on the cell type , and itsque band , and stit cells) . Moreovet cells) .Several complementary biological models have been generated for GAN, to study the disease mechanisms but also to provide robust systems for therapeutic development. Thus, tracers of the pathology have been very useful to validate or invalidate these novel tools. As discussed earlier, the most manifest cellular hallmark of the GAN pathology is the wide bundling of the IF cytoskeletal network throughout tissues. At the physiological level, alterations of the sensory and motor systems, leading to loss of sensitivity and motility in patients during adolescence are the common peripheral pathological signs that have been used to evaluate the robustness of animal models. Here, we describe the different GAN systems, present their advantages and limitations  and how GAN gene, analysis of several patients with identified mutations revealed that the ovoid perinuclear bundles, highly resistant to detergent is partial, conditional and dynamic  from patients. Thus, iPSC-derived motor neurons from distinct patients exhibit 3–4 fold increased in the abundance of the light-neurofilament protein (NFL), and more modestly peripherin, which still aggregates in motor neurons  at 15 days in culture . An initial study, performed on GAN culture , which w culture , and ali culture , to fit neration .Neurons from the dorsal root ganglia (DRG) of another GAN model were characterized . While tex1Δ, called GANJPJ in illustration no. 7 in ex3–5Δ for GANYY and GAN2ex3–5Δ for GANPB) leading to a premature stop codon. The first mouse to be described, the GAN1ex3–5Δ was presented as recapitulating the human pathology (ex1Δ and GAN2ex3–5Δ) presented both a mild phenotype with no overt neurodegeneration  motor performances solely in 129/SvJ mice from 15 months of age, and (ii) sensitivity from 12 months of age in C57BL/6 mice. These findings reveal the existence of modifiers genes for GAN that modulate specific functions of Gigaxonin in the motor and sensory systems. In addition to a late onset, the phenotype was quite mild, in comparison to the total loss of sensitivity and motility seen in patients during adolescence. Nonetheless, both GANex1Δ and GAN2ex3–5Δ mice exhibit the characteristic aggregation of IFs throughout the nervous system. Starting at the early age of 3 months, the steady levels of IF proteins  are increased in the brain, cerebellum and spinal cord of the GANex1Δ mice  in which upregulation of related genes contribute in maintaining functions in the context of deleterious mutations. This mechanism has been recently elucidated in both mouse and zebrafish species. Thus, in the presence of a premature stop codon on the mRNA (as expected in the GANex3–5Δ mice), the machinery leading to its degradation  triggers a specific signaling response to upregulate the transcription of related genes  with human. Second, the fertilized eggs are produced ex vivo. This allows various manipulations from one cell-stage, including gene knock-down (for recessive diseases), mRNA overexpression (for dominant diseases or rescue experiment) using microinjection and screening of libraries of chemicals by simple dilution in the water. Third, the high number of eggs generated per clutch provides substantial statistical power to experimental outcome. Fourth, the optic transparency of embryos permits to investigate neuronal and neuromuscular integrity at the physiological level, within tissues. Thus, the GAN orthologous gene, identified at one copy on the zebrafish genome was cloned and characterized. The zebrafish Gigaxonin (z-Gigaxonin) shows a 78% identity with the human Gigaxonin and shares the same domain organization with the BTB motif in N-terminus and six Kelch repeats at the C-terminus  in fertilized eggs to generate gan morphants. In the zebrafish community, this methodology, which impairs pre-mRNA splicing and blocks translation is widely used to silence gene expression. The discovery of the CRISPR technology, enabling the creation of stable KO lines evidenced that several mutants failed to reproduce the phenotypes described in the corresponding morphants ], their abnormal protrusion from the spinal cord, and a global abolishment of neuromuscular junctions  have been identified for Gigaxonin . They inIntermediate Filament regulation is the best-known function of Gigaxonin. Evidenced 2 years after the discovery of the GAN pathology , the aggAltogether, the complementarity of several laboratories, and the focus on non-neuronal primary fibroblasts have established that Gigaxonin is the first factor controlling the degradation of the IF family . This haTwo microtubule-associated proteins and one chaperone of tubulin have been identified as interacting partners for Gigaxonin: MAP1B , MAP8 D, and TBCIn light of the microtubule-binding capacities of the substrates, claims have been made to link microtubules (MTs) to GAN deficits and to convince on their relevance for the pathology, but these suffered from lack of reproducibility in independent studies and incomplete assessment see .MAP8 overexpression was shown to cause abnormal MT organization ranging from wavy pattern to aggregation, trapping dynein motor proteins . TBCB ovAnother concern is the relevance of MT-related substrates for neurodegeneration in GAN. Individually, MAP1B and MAP8 were shown to be sufficient to cause death when overexpressed in wild-type neurons, and to substantially improve survival rate when silenced in GAN neurons . These cIn conclusion, Gigaxonin controls important players of MT dynamics but the statement of their causal role, and of MT implication in the pathogenesis of GAN is an incorrect shortcut with our current knowledge. Additional work should definitively be performed to deepen this and identify possible roles of MTs in GAN.While the discovery of the pivotal role of Gigaxonin in controlling IF cytoskeleton was directed by its aggregation in patients, novel roles have recently unexpectedly emerged from exploration of the biological models of GAN.gan zebrafish constitutes the first robust animal model for the pathology , and only the second is impaired in gan zebrafish, leading to a total absence of secondary axons. On the contrary, primary MNs are generated but they project truncated and misguided axons, as mentioned above in three-dimensional imaging. Thus, these data revealed a differential and temporal effect, causing axonal abnormalities in the first wave, and an improper specification of MNs in the second wave, as further demonstrated by the down-regulation of Shh-responsive genes. Altogether, the different neuronal defects  in gan zebrafish impede nerve conductivity through loss of neuromuscular junctions that is sufficient to abolish locomotion. Considering the known roles of Shh signaling in neuromuscular specification, but also in axonal guidance  during the second wave in control embryos reproduces the gan phenotype, with “U-shape” somites and absence of secondary MNs. Conversely, increase of Shh activity (using purmorphamine) restores “V-shape” somites in 24% of morphants. The recovery of MN specification was obtained in gan treated embryos, but penetrance increases from 17.5 to 70% when drug was applied earlier (during the first wave), suggesting a Shh-dependent requirement of early event for sMN specification. Analysis of distinct biological models in zebrafish, mouse, and human demonstrated that Gigaxonin acts as a positive regulator of Shh. Thus, in situ hybridization revealed a decrease of Shh-responsive gene expression in gan morphants and mutants. In addition, repression of Gigaxonin in the Shh Light-2 reporter line impairs its responsiveness to the morphogen. Finally, translocation of Smo to the cilium, which represents an important readout of Shh activation is severely impaired in two independent GAN fibroblasts exposed to Shh, hence evidencing a decrease responsiveness to Shh in human cells. Deciphering the molecular mechanisms by which Gigaxonin controls Shh signaling would have been ideal in drosophila species, a powerful genetic system that is widely used in this field. Nevertheless, Gigaxonin is not conserved in fly, which may suggest that Gigaxonin participates in the evolution of the system in vertebrates  . E6-AP cHere, we will present E3 ligases that act as Gigaxonin on Shh signaling, expanding on other main pathways for spinal cord development and maintenance : Wnt, FGAs Gigaxonin, the Itch ligase regulates the turn-over of the Ptch receptor. Nevertheless, Ptch acts in absence of Shh, showing that Itch is not dispensable for canonical Hh signaling but essential to limit the proapoptotic activity of unliganded Ptch in non-canonical forms . The finThus, E3 ligases mutated in neurological disorders control essential players of cell signaling, and they can act at multiple levels in the same pathway (like NEDD4L) and even multiples pathways . Future investigations will probably increase this picture and further detail the elaborate mechanistic actions E3 ligases have on cell signaling. Considering that pathways also communicate between each other, mutation in a given E3 ligase may affect the equilibrium in many direct and indirect ways, hence representing a challenge when it comes to understand and treat pathophysiology in disease.Proteolysis, and in particular autophagy has been shown to be impaired in most neurodegenerative diseases. While this alteration can be indirect as a result of dysfunction of the neuron, we will discuss here the growing evidence culminating the last 2 years of the direct role of E3 ligases in regulating the autophagy pathway.Caenorhabditis elegans homologous of CHIP) activates the PI3KC3 complex, trough K63-ubiquitination of Beclin1 and several regulators , for its wide alteration of both the PNS and CNS, we discuss here 20 years of research on the genetic and functions of the Gigaxonin-E3 ligase. This led to an essential breakthrough in cell biology, where Gigaxonin is the 1st factor to date to control the degradation of the IF family, in and outside the nervous system. Exemplified by the massive aggregation of IF proteins throughout the body of patients, this pivotal cellular function is a signature for Gigaxonin across all experimental tools developed for GAN. The creation of mouse and, recently zebrafish models of the pathology led to major advance in the mechanisms underlying neuronal dysfunctions in disease. Thus, the recapitulation of the severe motor deficits of patients in zebrafish uncovered an unexpected role of Gigaxonin in controlling motor neuron birth and axonal outgrowth, through the regulation of Shh signaling. The As discussed in this review, other E3 ligases causing neurological diseases act in similar pathways. Among those, autophagy is the most prevalent, with third of E3s controlling multiple steps of the autophagic machinery. While this depends largely on the focus given by research groups, this review highlights that 23% of the E3 ligases bear functions in multiples pathways, with numerous ones acting at multiple levels within the same pathway. In this context, Gigaxonin, TRIM32 and CHIP are crossing all categories, by targeting substrates in cytoskeleton, cell signaling and autophagy. This current view is undoubtedly going to expand in the future, but it already highlights the big challenge we are facing when thinking about therapy.UBE3A gene, to restore endogenous level of E6-AP , while GAN benefits from a phase I gene therapy approach . Reintroducing Gigaxonin expression is in principle a promising approach, if appropriate level of the E3 ligase versus endogenous protein was determined. While we are assured that too much expression will generate serious deleterious effects, just mentioning the complete destruction of cytoskeleton, the risk of too little Gigaxonin is no impact on neurological signs. In absence of a robust GAN mouse and lack of demonstration that IF aggregation plays role in neurodegeneration, the benefit of this strategy (using a weak promotor) remains uncertain. To circumvent this, stabilizing the mutated E3 ligases (as it is the case for Gigaxonin) or modulating its activity (for dominant mode of inheritance) in disease constitutes an interesting approach, but knowledge on crystal structure are necessary for the latter. Another direction relies on the creation of powerful model systems to perform pharmacological screening, hence providing physiological relevance to candidate drugs. When it comes to mechanistic-driven approach, the pathologies discussed here may benefit from decades of pharmaceutical efforts done in other field, in particular cancer to potentiate or repress cell signaling, among which autophagy is certainly one prolific area of investigation  a repressor transcript of the paternal f E6-AP [ and Clintigation . Thus, atigation .As we are expanding our understanding of the functions of E3 ubiquitin ligases, there is a need to integrate them in a common ground in the future, to apprehend the complexity and the potential cross-talk between pathways in the settings of neurological symptoms. This constitutes a challenge, but the impact will be extremely high, by enriching our comprehension of cellular functions, and helping defining the best therapeutic strategies that can benefit multiples neurological diseases. Moreover, modulating activity of the wild-type E3 ligases is extremely relevant for many other diseases, if we consider their known roles in various functions such as DNA repair, cell division, apoptosis and immunity. Extensively studied in that respect, Itch represents a valuable therapeutic target for cancer, skin and immune diseases . FinallyPB wrote the manuscript, generated the table, and designed figures. LL executed complete drawing of figures and provided critical inputs into manuscript and figures. Both authors performed the bibliography search and reviewed the manuscript.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Unaddressed hearing loss is a growing public health concern that negatively impacts daily life including communication, behavioural and social interaction and emotions, identity, and psychological wellbeing . The benEffective patient-clinician communication is an essential part of patient-centred care ; howeverA patient’s hearing aid usage may differ based on factors including the degree of hearing loss , lifestyRecently, research has focussed on enhancing the ecological validity of audiological assessment  and the This study was approved by the UCL Ethics Committee (project no. 3866/001). Data was kept in compliance with the General Data Protection Regulation (EU 2016/679). Each participant provided written consent, personal identities were anonymised during transcription and audio recordings were subsequently destroyed.Experienced hearing aid users  with no known neurological conditions were identified through a database of individuals with hearing loss who had volunteered to take part in research studies at the UCL Ear Institute, London, England. Experienced hearing aid users were targeted for this study (rather than first time users) because of their increased exposure to a range of audiology services and clinicians as well as increased awareness of the hearing healthcare pathway. Email invitations were sent to potential participants who had been in contact with their audiology provider within the last 24 months.Purposive sampling with maximum variation was employed to prioritize enrolment of eligible participants in the one-to-one interviews to maximise diversity of views and experiences . Upon exA total of 21 adults with an average of 17 years of hearing aid use participated in this study with different populations for the focus group (7 participants) and for the semi-structured interviews (14 participants). Demographics are provided in The present study implemented a semi-structured approach in an effort to understand “participants’ experiences, how they describe their experiences, and the meaning they make of those experiences” in an extended conversational format . The topThe focus group was carried out first, as an explorative process, to ensure the target discussion topics were easily interpretable, aligned with the main research questions, and were appropriate for use within the semi-structured interview format . All focFocus group and interview sessions were conducted between January and March 2021. The focus group was carried out via Zoom because all participants had previous experience with this platform, did not require closed captions, and were comfortable with the visual gallery layout. Semi-structured interview participants chose their preferred online platform (Zoom or Microsoft Teams) based on their personal communication needs . All participants were offered a 1:1 trial call prior to the main session to check audio and internet quality.The interview facilitator (B.P.) hosted each video call from a professional setting within their own home. Participants took part in the online video conference from their own homes and were encouraged to sit in a well-lit room with minimal background noise. Participants wore their hearing aids throughout the video call and chose to use either headsets, Bluetooth streamers, or loudspeakers based on their communication needs. The virtual waiting room was open an hour before each call was scheduled to allow for audio and/or Bluetooth connection testing.Focus groups of six to ten participants are generally optimal for ensuring all individuals are able to contribute and provide a range of views without being led by the consensus of a larger group . The natSpecific instructions were provided to respondents prior to the focus group session time to optimise communication and replicate the interactive nature of in-person focus groups as best as possible see . During Due to the one-to-one nature of the semi-structured interview, participants were able to use their preferred communication device (including smartphones); all parties kept their cameras and microphones switched on for the duration of the interview. On average, each interview session took approximately 46 minutes (range: 35 - 58 minutes). To avoid fatigue, the facilitator ensured interviews did not exceed the maximum allotted time of one hour .Iterative-inductive thematic analysis with a descriptive phenomenological approach was used to identify, analyse and report patterns within the data . The preInductive (bottom up) thematic analysis was implemented by the first two authors, such that coded data were organised into general themes centring around experiences during audiology appointments and patient-audiologist communication. A saturation point was reached after inductive coding of the 11th interview (participant PQ) and was confirmed by carrying out three additional interviews for which no new themes emerged. The first and second authors double coded 25% of transcripts and any discrepancies were resolved at two separate timepoints within the study.Here, participants focussed on their recent audiology hearing assessment experiences. Two key themes were identified: 1) testing procedure and 2) relating tests to real world hearing difficulties.“Something that really stood out in my mind, no matter how faint the noise is that it’s just as important as the louder ones. Now in the past I remember I’ve sat there thinking can I hear that? … this time I was really determined that I was gonna press it if it was there was even a quiet sound” – LK Participants described their experiences undergoing pure tone audiometry, including aspects of the patient-audiologist interaction and certain testing instructions that helped them feel more comfortable. “It made me realise what I couldn’t hear, because he did a test first of all without my hearing aids in and then he read the words again in a different order with my hearing aids in and it made me understand what letter sounds that I couldn’t hear, what I was mixing up. That was very useful from a self-awareness point of view” -HG And then I went private and he kind of explained to me, this is how it works in terms of picking up speech and really emphasised on speech in testing. And I was able to really kind of understand what I couldn’t hear and why I couldn’t hear certain sounds in relation to my hearing loss. So, it’s really interesting. – RS Some participants mentioned completing speech testing during audiology assessments and several reported the value for understanding the benefits of their hearing aids when switching between aided and unaided testing. “They ask: ‘how does that sound?’ & ‘are you comfortable with that?’ and yeah that’s usually how it’s done” - WX Participants described the experience of aided assessment once new hearing aids had been fitted or existing hearing aids had been adjusted, with a variety of aided testing techniques e.g., speech perception testing or presentation of distractor stimuli. However, some participants reported that the audiologist tended to ask them for their opinions of the hearing aid sound quality rather than performing any aided assessments or using outcome measures. “And I think it gives you confidence to know that you can pick up certain speech with the hearing aids you’ve got, kind of the reassurance to know I can still pick up speech” -RS The benefits and challenges of replicating externally valid situations in a controlled clinical environment were discussed in detail. For example, the significant limitation of conducting hearing aid fittings in a quiet room was emphasized, as was the benefit of using speakers to play background noise to simulate noisy environments. When realistic sounds and background noise were used within the audiology assessment, participants reported feeling more confident wearing the hearing aids outside of the clinic and expressed a lower need to return to the clinic for adjustments. “They would test different noises and then I’ll put one [hearing aid] in and the other one in to see how it felt and their voice as they were speaking to me, but it’s not a good test of the real world to be honest because of course you know my perfect world isn’t one of being quiet without background noise. That’s not how we hear” - ML Other respondents did indicate, however, that a simulated environment was still very unrealistic compared to everyday challenging listening situations. “I can hear you in a completely silent room, but as soon I walk out the door it isn’t right. So, the advantage and it’s not perfect, but you can actually have the audiologist or receptionist or someone random person that happens to be in the building, come in and they can have a conversation while you’ve got music or street sounds on, so it gives you a much better idea because they can tweak it while you’re there” -ON “I’ve had the thing that mimics restaurants. If only they could come with me or if only they could just come with me and tell me about the street, or come to work with me.” - LK “You’ve got all the other kind of speakers that generate all sorts of background noise so that you can try them in background noise and then you can wander out in the street in them for a few minutes and come back” - NO Some participants believed that it would be beneficial to record their listening difficulties in environments they experience regularly  or have a trial period wearing hearing aids outside the clinic with the option of providing immediate feedback. Participants discussed their experiences within specific scenarios they had experienced or in relation to communication techniques they hoped audiologists would incorporate in future meetings. Three key themes were identified: 1) importance of communication strategies, 2) explanation of test results, and 3) patient-centred care. Participants felt that the lack of individualised care and inadequate communication strategies amongst practitioners negatively impacted their experiences.“I’ve had it where I’ve had my impressions taken, they’ve filled my ears obviously with the putty and start talking to me and I’ve not looked at them. And then it’s kind of… I laugh about it. Quite often I’m one of those I kind of brush things off quite a lot” -QP “I mean many times I’ve been sat there unaided, with the audiologist talking to me, turning around to put the tube in and I think don’t you know… you of all people must know I can’t hear a thing you’re saying. It’s just annoying.”-WX “Some audiologists really have… very minimal experience of working with patients like myself, with the type of hearing loss that I have. One had a tendency to over-pronounce and I said you don’t need to speak to me like I’m a five-year-old”-RS “And the audiologist is clearly checking setting your hearing aids against whatever’s on the computer. And if you felt like they were concentrating on something, and then you had a question… Would you feel comfortable to ask it?” -AB Firstly, participants emphasized the importance of professional development training regarding communication skills and deaf awareness for all audiology staff, including receptionists. Participants also recounted specific situations where audiologists had not used adequate communication skills  and indicated that some healthcare professionals did not seem aware of the communication barriers people with hearing aids face. “the first thing I would do is I would arrange for them to have a week with earplugs in. Just so they would appreciate what people who can’t hear are up against. It happens every time when I don’t have the aids in my ears because they’re adjusting them and they try and speak to me, I do that [points to ear], and they realise I can’t hear them”- WX “Somebody with really good deaf awareness that faces you when they speak, they explain what they’re going to do before they do it, they’re not somebody that just comes and says right sit in that booth, I’ll put these on, press the button when you hear something” – HG To better understand the first-hand experience of hearing loss and the perspective of their patients, experienced hearing aid users suggested audiologists should spend time with temporary simulated hearing loss . The importance of having working loop systems and visual displays in the reception areas to alert patients was also stressed “I think possibly if more deaf people were involved in audiology, not just one deaf audiologist, but if more people, more deaf people were involved all the way through then there might be some changes.” – FE “My audiologist was Deaf and it was quite an experience. I knew that the person had really good understanding, really good deaf awareness because not all audiologists that I’ve seen have a good deaf awareness. - HG Finally, some participants reported positive experiences involving being seen by audiologists with hearing loss. In these cases, they felt the audiologist had an enhanced awareness of the impact of hearing loss and a unique ability to relate to the hearing difficulties experienced by patients. “In the reception I feel like…do I really have to tell you that I’m deaf? I would’ve thought in this environment this is somewhere where I’m safe, you know where I’m with like-minded people and I don’t have to explain myself” -LK “There’s a big waiting room, the audiologist calls my number and then they walked away and didn’t have a chance to see the lip reading or anything.” -LM Some participants also reported communication barriers in the waiting area and with administrative staff. “I mean it appears on the screen and I sort of look vaguely at the screen but not with great interest, I trust, I trust her.” – TU “My audiologist just said something like, well there’s not much change.” – CD “Because when they do the testing, they didn’t tell me the results of the testing, of how beneficial my hearing aids actually were. I just felt like I had this massive gap in my knowledge and my understanding of my hearing and it’s my hearing, it’s mine, no-one else’s”. – RS Participants explained their general understanding of audiometry results and they reported engaging in varying levels of explanation with their audiologist when interpreting test results. Some respondents felt their audiologist’s description was sufficient for their needs and trusted the audiologist’s judgement without requiring additional detail. Others, however, were not shown the audiogram and felt they would have benefitted from more information., Some participants felt audiologists assumed audiograms had been explained to the patient in depth at an earlier date because they were long-term hearing aid users and thus were simply comfortable reporting when there were no significant changes to hearing thresholds, even if the patient was unfamiliar with audiogram reports. “They say there has not been much change and it’s like well actually I want more information than that because my hearing’s really important to me. It is about understanding how to interpret an audiogram for one. Oh yes, oh this is why I can’t hear these sounds that I know… It can give me more confidence.” - RS “My graph, it’s my hearing, I always get a copy. I’ve got a copy of nearly every test I’ve done. If I’m not offered it, I get offended. I want a copy.” – NO “when it was explained from my graph that the low frequencies were the ones that I was missing which is why I find men more difficult to hear often because they’ve got lower voices or deeper tones and that sort of, it was almost like a little bit of a jigsaw puzzle going oh, that’s why I can’t hear speech” – HG Hearing aid users who received a more thorough explanation reported more benefits in terms of linking pure tone thresholds with relatable sounds in their everyday environments. Moreover, participants felt the process of linking audiogram results to everyday sounds gave them a better understanding of why they could not hear certain sounds in their daily life and helped them feel more confident in relaying results to communication partners. Many respondents felt they would have benefited from being given a copy of their audiogram results to monitor the progression of their hearing loss and consolidate their knowledge outside the clinic. “And so, the impression I get from audiologists is they think my lifestyle is just like an old person’s lifestyle and it isn’t. Every patient is different and that’s really crucial to the advice they can give as an audiologist.” -RS “Just with having one conversation she really got it, straight away, she saw how upsetI was and understood about the impact it has, because that’s it isn’t it, it’s not just oh you know you have a bit of trouble with the phone, it’s like well that impacts on everything. So, I think the wider issues that hearing loss brings, not just to my identity, to how I fit in with you know my relationships, going out- everything” - ML Participants shared experiences of individualised care within audiology services and recommendations for improvements in this area. A key suggestion was to include more specific, personalised questioning within the assessment, especially regarding the impact of hearing loss on employment, education, leisure, and home life, so audiologists could provide or recommend suitable intervention options. “My audiologist made me feel that he was committed to my needs, my specific ones. With a lot of audiologists it’s about right ‘let’s give you technology’, but my audiologist knows my needs above the hearing aids are really important. And I know that if things weren’t right I could ring and he’d get me in tomorrow. You know that’s the big difference” -LK “It was more about the hearing aids than the person with the hearing loss. And it shouldn’t be”. -HG Hearing aid services have high technical demands, therefore participants felt audiologists need to balance optimising hearing aid technology  with patient communication. This could help services become more patient-focussed (rather than the technology- or clinician-focus). Other experienced hearing aid users wanted to know more about the technological capabilities of their hearing aids and additional devices that could be beneficial for managing hearing difficulties at home or at work. “you have a relationship and I think that relationship and trust is really important. I realise it’s not always possible to see the same person, but I think if it can be done it’s important” – LK “Seeing the same audiologist is hugely important, and it’s taken me a while to find the right person. I’ve been through so many audiologists” – NO “I don’t think it makes any difference, you only see somebody once every three years you know, it’s not personal in any way” – FE Experienced hearing aid users also commented on the impact of clinician continuity in hearing aid services. Some participants felt it was vital to see the same clinician at each appointment because they had taken time to build the rapport and trust. However, others felt that it was not so important if there was a significant amount of time between appointments. I've only been in one time, where someone has actually taken the time to go into detail. Where they ask how the hearing aid sounds, and really listen to the answer to suggest alternative settings. Apart from that, it's always been once we've gone through the test, they ask are these settings and if any problems, give us a call. They don't get time to get to know you”- CD ““I think with the public sector the biggest learning curve was to ask a lot more questions. I would say to anybody going to an audiologist-. ask them questions, tell them what you need your hearing aids for, what’s most important to you. From a private provider they actually do that because you know you’ve got your nice hour-long appointment to have a chat and develop a professional relationship. I think it’s really important.” – HG Finally, hearing aid users reported time constraints within the audiology consultation as a key barrier to patient-centred care. To ensure that hearing aid services meet the needs of service users, a greater understanding of user experiences and proactive adaption to service delivery is necessary. To address this, the present study used an online focus group and a series of semi structured interviews to highlight key elements of the audiology assessment process and communication experienced hearing aid users’ value.Adults with hearing loss have previously reported that audiologists were not in tune with their communication needs, instead using “information dumping with a script like approach” . This reBeyond audiometry, interviewees reported having minimal experience with formal aided and unaided functional hearing assessments, including the use of speech and/or background noise. Instead, it appears audiologists tend to rely on patients’ self-reports to determine hearing aid sound quality within the consultation room, thereby limiting ecological validity relating to everyday environments. Some hearing aid users felt it would be beneficial to keep track of hearing aid sound quality across a range of real scenarios . However, the extended period between audiology appointments, particularly within the public sector, would mean that such feedback may not be considered in a timely manner. The use of remote care and ecological momentary assessment  could provide a solution to increasing responsivity to feedback in audiology and accommodating time-sensitive adjustments .Hearing loss can negatively impact communication and participation in activities  and thusBy definition, many patients presenting at an audiology department will have some form of hearing loss. Therefore, it is imperative audiology environments are as accessible as possible for the hearing impaired. However, a recent survey revealed that assistive communication devices were only available in 64% of audiology reception areas . The curThe financing and distribution of hearing aids varies globally; some countries offer universal or selective public insurance for hearing aid services , whereas others rely solely on private insurance or out-of-pocket payments  comprehensive, relatable hearing assessments, 2) clear, concise, deaf aware patient-audiologist communication, 3) accessible services and 4) a personalised approach to recommend suitable technology and address patient specific aspects of hearing loss.Supplementary Material


Better information is needed about how declines in sensory and cognitive function affect older drivers. This study assessed how hearing loss affects engagement in four challenging driving patterns. Data from the AAA Longitudinal Research on Aging Drivers study was used, including objectively-measured driving; three measures of hearing: reported hearing aid use, self-rated hearing, and the Whisper Test; visual acuity (Tumbling E); and cognition (Trail Making B). Failing the Whisper Test in both ears was related to significantly lower percentage of trips (%trips) at night, on freeways, and during rush hour, but a higher %trips >15 miles. Hearing aid use and self-rated hearing were not associated with any driving differences. Worse vision was related to a lower %trips >15 miles, while worse cognition was associated with a lower %trips at night, on freeways, and during rush hour. The Whisper Test interacted with cognition for rush hour trips.


The BAHA (bone-anchored hearing aid) Attract is a magnetic transcutaneous bone conduction device anchored into the temporal bone. The standard surgical technique for BAHA Attract is a multi-tools time-consuming process, which requires a large cutaneous incision. The objective of this study is to describe and test the feasibility of a minimally invasive pocket (MIP) technique for Magnet Bone Implant Hearing Aid (MBIHA) with a modified magnet of BAHA Attract without fixation and without any tissue reduction. We use a 3-cm vertical skin incision and a subperiosteal pocket.A study of 10 patients with conductive or mixed hearing loss who benefited from a MBIHA using the MIP technique is presented. The pure tone average (PTA) (dB) for air-conduction thresholds and the speech recognition threshold (SRT) (dB) in speech audiometry in quiet are calculated. The Entific Medical Systems (EMS) questionnaire and the postoperative clinical outcomes are realized.We found a significant improvement of 33.8 dB on average for the PTA and 44.8 dB for the SRT with MBIHA at 3 months, compared with unaided situation. No implant was removed or displaced after 2 years of follow-up. The skin condition remains intact in all the cases.The minimally subperiosteal pocket surgical technique MIP without fixation and with tissue preservation for the MBIHA is safe, rapid and effective for patients with conductive or mixed hearing loss. It opens new perspectives of development and modify conventional concept in magnetic coupling of bone-conducted device.The online version of this article (10.1007/s00405-019-05746-5) contains supplementary material, which is available to authorized users. Bone conduction hearing aids (BCHA) are well-accepted treatment options for audition restoration in conductive or mixed hearing loss, or in single-sided sensorineural deafness when conventional hearing aids are not tolerated or indicated, or after inefficient ossiculoplasties. Chronic otitis media, atresia of the external auditory canal and otosclerosis are the most frequent otological indications reported.Bone-anchored hearing aid (BAHA) is a sound processor transforming sounds into vibrations, which are transferred via an osseointegrated implant to the skull bone and finally to the cochlea.BAHA are divided into percutaneous (skin penetrating) and transcutaneous (non-skin penetrating) types. They are both fixed by an abutment to the bone.A softband, a bone vibrator on band, or a soundarc are used for pre-operative testing or in young children who are not ready to receive a bone anchored implant because of insufficient bone thickness.The first percutaneous osseointegrated BCHA was the BAHA with a permanent skin-penetrating abutment. Despite the good hearing outcomes –3, this Cochlear Bone Anchored Solutions AB  developed the BAHA Attract in 2013. The BAHA Attract is composed of the same titanium implant (BI300) fixing the magnet (BI400) under the skin. The second external magnet is coupled magnetically with the processor. Many studies –13 have The magnetic transcutaneous anchored BAHA Attract does not have skin-penetrating abutment. It stimulates the bone by vibration of the fixed magnet through the intact skin. The advantage of transcutaneous bone conduction hearing aids is to reduce partially skin complications compared to a percutaneous abutment and need skin thinning if skin thickness is more than 6 mm. This conventional technique partially improves esthetic results, but a large 8 cm retroauricular scar is still needed.The standard surgical technique for Attract recommended by the manufacturer is relatively complex. It implies a specific technique, multi-tools instrumentation, and constitutes a time-consuming process, requiring a large horizontal cutaneous incision ("C" shaped in retro-auricular region of 75 mm). Recommended surgery also requires the creation of a skin flap, together with bone drilling to smooth out the area for bedding the internal magnetic implant, and the use of a screw fixation system (BI300) titanium implant to attach the magnet to the bone. In case of skin exceeding 6 mm thickness, the manufacturer recommends flap thinning .The major complications described (5.2%) , 15–17 aTherefore, we claim that the goal of developing the BAHA Attract system is only partially fulfilled the anchoring process still imposes a direct percutaneous approach or an important cutaneous flap to attach perpendicularly the magnet to the bone, which implies skin damages. To minimize those hardships, we tested an unanchored magnet implantation that minimizes vertical skin incision, adapted to the size of the magnet (2.7 cm).To our knowledge, it is the first description of a minimally invasive pocket surgical technique (MIP) for implantation of the Magnet Bone Implant Hearing Aid (MBIHA). The MIP technique for MBIHA differs from the standard surgical technique by making a small 3 cm vertical incision distant from the implant and a subperiosteal pocket to insert the internal magnet directly on the bone. No skin flap, skin modification (thinning), bone drilling or fixation is necessary.The objective of this study is to investigate the surgical minimally invasive pocket (MIP) aspects and to determine the audiological outcomes of MBIHA without fixation.This clinical study was accepted by the Hospital-Faculty Ethics Committee of Tivoli Hospital (Ref: B096201734622).Between January 2017 and January 2018, 11 patients were implanted with a modified BAHA Attract, using the MIP surgical technique. We used the term “Magnet Bone Implant Hearing Aid” (MBIHA) in our study.Eleven patients received MBIHA, including 4 patients with conductive unilateral hearing loss, 1 patient with conductive bilateral hearing loss, 3 patients with mixed unilateral hearing loss and 2 patients with mixed bilateral hearing loss. One patient had a single-sided sensorineural deafness and was excluded from this study to reduce bias when interpreting the audiometric results.The mean air–bone gap  was 30 dB SD, 12.9 dB). Chronic otitis media and otosclerosis were the otological indications for a BAHA Attract in our patients. Eight patients had a surgical history on the implanted side. The sex ratio (F/M) was 6/4 and the median age was 38 years (12–64 years). The clinical characteristics of these 10 patients are detailed in Table 2.9 dB. CThe test device was the Cochlear Baha 4 Attract system .The internal titanium BIM400 Implant magnet was placed underneath the skin and the Baha SP (sound processor) snaps onto the external magnet placed on the skin surface. The SP Magnet and the unfixed modified BIM400 Implant Magnet of 27 mm diameter were coupled by a magnetic retention.The BI300 implant was not used.The tip of the BIM400 internal magnet was removed by drilling to obtain a flat surface and the screw was removed.External processor was the same as for conventional use and a Soft Pad was placed between the external magnet and the skin. Different magnet forces were used.All surgeries were performed under general anesthesia.Markage on the skin of the future cutaneous incision and the internal implant site projection was done with a pencil. Infiltration with a local anesthetic 1/100,000 or 1/200,000 xylocaine/adrenaline and 3 cm skin incision was realized.If a pre-existing scar was present, we used the most posterior one, otherwise the incision was placed into the retroauricular fold.The position of internal implant was usually 5–6 cm from the external ear canal.The distance between the musculo cutaneous incision and the front edge of the magnet should be at least 2 cm.Detachment of the subperiostal plane was carried out with a freer suction elevator  and the modified magnetic implant BIM400 was simply inserted into the pocket. Motor drill or classic instrumentation was not used.No suture, bone or periosteal, was necessary.Nor subcutaneoous tissue nor muscular tissue was removed even in case of thick skin.The pocket was closed in two layers.Compression bandage was maintained for a week.Free-field hearing tests were performed in a soundproof audiometric chamber for unaided situation, with the BAHA on soundarc and with the MBIHA at 2, 4 and 6 weeks, 3 and 6 months after surgery.A masking was applied to the non-tested ear.In pure-tone audiometry, the hearing threshold for air-conduction (PTA) was calculated as the average of the thresholds measured at 0.5, 1, 2 and 4 kHz. This threshold was measured in decibel Hearing Level (dB HL or dB).Speech audiometry in quiet was evaluated by measuring the speech recognition thresholds (SRT in dB HL) for 50% correct using dissyllabic words list (Fournier).Satisfaction with MBIHA was assessed in all patients using a standardized questionnaire derived from the BAHA Entific Medical Systems (EMS) Questionnaire , 20.This questionnaire quantified the daily use of MBIHA in different situations and assessed the satisfaction and impact on quality of life.Per and postoperative complications such as bleeding, subcutaneous hematoma, pain, skin rash, wound infection, or migration of the implant were noted.The Wilcoxon signed rank was used to compare the differences between paired groups  for quantitative data  (dB). Means  were reported.p value less than 0.05 was accepted as significant.All analyses were performed using the XLSTAT software . A Hearing threshold for air-conduction (dB) calculated on 500, 1000, 2000 and 4000 Hz, without hearing aids, with the BAHA on soundarc and with MBIHA at 2, 4, 6 weeks, 3 and 6 months were collected for each patient in Table Mean PTA was 65.9 dB  without hearing aid, 35.5 dB  with BAHA on soundarc and 40.6 dB  with MBIHA after 2 weeks. Improvement in aided hearing performance over time was observed. Mean PTA calculated at 3 months postoperatively reached 32.1 dB   with the test device at 3 months compared with unaided hearing situation. But no statistically significant difference in PTA compared with BAHA on soundarc was founded.Pure-tone audiometry showed a statistically significant improvement in PTA of 33.8 dB  with MBIHA were, respectively, 27.2 dB, 25.5 dB, 30 dB, and 45.5 dB  (dB) calculated without hearing aids, with BAHA on soundarc and with MBIHA at 2, 4 and 6 weeks, then at 3 and 6 months, were summarized for each patient in Table Mean SRT was 60.1 dB  without hearing aid, 24.6 dB  with BAHA on soundarc and 25.3 dB  with MBIHA at 2 weeks. The mean SRT calculated at 3 months postoperatively reached 15.3 dB   with the test device at 3 months compared with unaided hearing situation. There was also a statistically significant difference in SRT improvement in favor of the MBIHA compared to soundarc (p = 0.01).Speech audiometry in quiet showed a statistically significant improvement in SRT of 44.8 dB  are expected in the future.The 8 cm C-shape incision recommended for BAHA Attract includes horizontal components. Confection of cutaneous flap can potentially compromise the parieto-temporal vascularization by horizontally crossing two major arteries, the posterior branch of the superficial temporal artery and the posterior auricular artery, as described by Perenyi et al. . MIP tecMajor complications such as dehiscence, wound infection, cutaneous necrosis or migration are not reported in our study, after an average follow-up of 26 months. One patient developed transient cutaneous erythema in the magnet area resolved by decreasing the magnetization force of the external magnet from 4 to 3. Cooper et al.  describeThe MIP technique has been already used in our hospital and by some authors for the insertion of the internal receptor-stimulator of cochlear implants (CI) –25. AmonIn a case of surgical revision of CI, operated according to the MIP technique, a spontaneous bone bed printing was observed after 2 years of the implantation . We can To our knowledge, no other study was carried out using this minimally invasive surgical technique for MBIHA implantation. Actual publication still tend to find new less invasive approaches for the percutaneous abutment , compared to the standard surgical technique  is similar, or better than those described in the literature with BAHA Attract on patients with conductive or mixed hearing loss. These Studies revealed a mean improvement in PTA of 31 dB  and 17.Pure-tone audiometric results disclose significant improvement on all frequencies. We confirm a better improvement over 500 and 1000 Hz and a decrease in hearing performance over 4000 HZ, as described in the literature –11, 29. Mean improvement in SRT with MBIHA at 3 months (44.8 dB ± 10.1 dB) is better than mean improvement in SRT measured by Iseri et al.   questionnaire demonstrate an overall satisfaction score of 9.1/10 with the MBIHA with an improvement in quality of life reported in 9 patients. Seventy percent of patients use their MBIHA more than 8 h per day and 100% of patients use between 5 and 7 days per week, suggesting good efficacy and comfort for most patients. Our results of the EMS questionnaire are comparable to those of the literature with BAHA , 20. PowMRI realization will lead to the same problem than with the Attract and for the magnet of a CI standard unfixed magnet. A 1.5 Tesla MRI could be carried out with standard caution and bandage compression. Even if we did not remove any internal magnet until now, it may be easier to extract the internal magnet placed with the MIP technique than with the fixation technique, if a 3 Tesla MRI is absolutely needed.Our surgical technique is interesting as it potentially addresses some of the concerns with BAHA implantation; most specifically the need for adequate calvarias thickness and solidity to support osseointegration of the implant fixture as well as limited impact on the retroauricular skin for a similar efficiency.It is a very simple “single tool” technique giving comparable result to those obtained with the soundarc, the BAHA Attract system or the percutaneous abutment. We demonstrate that rigid fixation is not needed to obtain excellent audiometric results.Finally, magnetic coupling of a BCI processor becomes unspecific to one producer and should stimulate development of a larger number of processor products, which address patient concern like aesthetic, price and performance. Minimally aspect of the procedure and future work on MRI compatibility of the magnet  promotes the MBIHA using MIP technique, particularly for a pediatric population or patients with poor bone condition, like Lobstein disease or post radiotherapy.Easier to performMinimal instrumentation requiredMinimal 3 cm vertical incisionFaster healingEarly fitting possibleBetter esthetic resultTime savingThe minimally invasive pocket technique described for the first time in our study for the Magnet Bone Implant Hearing Aid possesses several advantages over the standard technique for BAHA Attract:The size, the orientation of the skin incision, any skin thinning and the subperiosteal detachment are important factors to preserve the cutaneous perfusion of the retroauricular tissue on and near the implant, allowing to reduce complications. Our results confirm the minimally invasive aspects of the MIP technique without implant migration. The MIP technique preserves the retroauricular skin. It must than be recommended for BCI, especially in pediatric population with thin bone and in patients with poor quality bone. The audiological results obtained with MBIHA without fixation and implanted using the MIP surgical technique, in patients with conductive or mixed hearing loss, are comparable to the results described with the standard surgical technique.Supplementary file1 (MP4 137079 kb)Below is the link to the electronic supplementary material.


Auditory neuropathy spectrum disorder (ANSD) refers to a range of hearing impairments characterized by deteriorated speech perception, despite relatively preserved pure-tone detection thresholds. Affected individuals usually present with abnormal auditory brainstem responses (ABRs), but normal otoacoustic emissions (OAEs). These electrophysiological characteristics have led to the hypothesis that ANSD may be caused by various dysfunctions at the cochlear inner hair cell (IHC) and spiral ganglion neuron (SGN) levels, while the activity of outer hair cells (OHCs) is preserved, resulting in discrepancies between pure-tone and speech comprehension thresholds. The exact prevalence of ANSD remains unknown; clinical findings show a large variability among subjects with hearing impairment ranging from mild to profound hearing loss. A wide range of prenatal and postnatal etiologies have been proposed. The study of genetics and of the implicated sites of lesion correlated with clinical findings have also led to a better understanding of the molecular mechanisms underlying the various forms of ANSD, and may guide clinicians in better screening, assessment and treatment of ANSD patients. Besides OAEs and ABRs, audiological assessment includes stapedial reflex measurements, supraliminal psychoacoustic tests, electrocochleography (ECochG), auditory steady-state responses (ASSRs) and cortical auditory evoked potentials (CAEPs). Hearing aids are indicated in the treatment of ANSD with mild to moderate hearing loss, whereas cochlear implantation is the first choice of treatment in case of profound hearing loss, especially in case of IHC presynaptic disorders, or in case of poor auditory outcomes with conventional hearing aids. Auditory neuropathy spectrum disorder (ANSD) refers to a range of hearing dysfunctions characterized by compromised signal processing along the auditory nerve or by deficient transmission of this signal to the auditory nerve by the presynaptic inner hair cells (IHCs). Its diagnosis is in part based on evidence of altered neural processing such abnormal auditory brainstem responses (ABRs), with a reduced or absent wave V, despite evidence of preserved outer hair cells (OHCs) responses, such as otoacoustic emissions (OAEs) and/or cochlear microphonic (CM). ,2,3,4. TANSD was first described by A. Starr and colleagues in 1996 in ten patients presenting with evidence of normal OHCs function but impaired neural transmission in the peripheral auditory system . The terMore recently, studies of genetics and molecular biology on animal models have shown a wide range of localization of the sites of impaired functioning, ranging from the area of inner hair cells (IHCs) synapses to the auditory neural fibers ,12,13. AThe clinical profiles of ANSD are largely heterogeneous, according to the variety of possible etiologies. ANSD may results from both syndromic and non-syndromic genetic anomalies, environmental causes, as well as structural anomalies. Among these, cochlear nerve hypoplasia or aplasia, variable lesion sites and congenital-neonatal or lately acquired dysfunctions have been described.Special attention must also be paid to the concept of hidden deafness or hidden hearing loss (HHL), which corresponds to a hearing impairment in which speech discrimination in challenging auditory conditions  is abnormally impaired as patients also display normal pure-tone and speech audiometry thresholds in quiet. HHL is associated with well-synchronized ABRs. This auditory processing disorder may be caused by a specific synaptopathy-neuropathy, limited to auditory fibers responding to high intensity sounds with preservation of fibers responding to low intensity sounds ,19. ThisThis article provides a literature review on ANSD management with a special focus on its etiologies, audiological assessment and rehabilitation. In order to describe the variability of physiopathological and clinical features of ANSD, we used a conceptual approach based on the site of the lesion, from the more distal to the proximal site of the sensorineural pathway. Moreover, few own case reports have been described.The prevalence of ANSD remains uncertain, and studies report prevalences ranging from less than 1% of hearing impaired patients up to 10% ,21,22,23Newborns discharged from a neonatal intensive care unit (NICU), about 10%–15% of newborns, have a higher prevalence of sensorineural hearing loss (SNHL), and particularly of ANSD ,25. The A run-through of the normal process of cochlear transduction of an auditory signal into an electrical impulse transmitted along the auditory nerve is essential for understanding the underlying mechanisms implicated in ANSD as well as the heterogeneity of its clinical manifestations.2+ channels at the presynaptic site of the ribbon synapse triggers a high rate synaptic vesicles fusion, leading to the release of glutamate through the synaptic cleft. The presynaptic signal is transferred in a graded manner in order to respect the rate code of the spike of the fibers of the spiral ganglion neurons (SGNs).The IHCs are mechanosensory cells that convert mechanical deflections of the hair bundle at their apex into a molecular signal suitable for triggering the electrical firing of neuronal fibers. The deflection of the hair bundle of IHCs after the vibration of the tectorial membrane generates a cation influx in the IHCs body. The consequent depolarizing potential allows a calcium influx through a single or two voltage-gated calcium channels. The coupling of Ca2+ sensitive receptors, the AMPA receptors, leading in turn to the generation of the neural spike at the level of SGNs fibers, that travel along the axon to the SGN cell body. The effective encoding of auditory stimuli relies on rapid and precise spike initiation in auditory nerve fibers. Preservation of the graded presynaptic signal, of the high-rate kinetics of synaptic release and of the rapid restoration of postsynaptic membrane activation, are primordial for the precise encoding of temporal features of auditory stimuli. Effective frequency phase-locking of firing in the SGNs fibers to the frequency of the auditory signal is also an essential element for pitch encoding of pure-tone sounds up to 1 kHz in frequency ..42].The current management of individuals presenting with ANSD varies according to the severity of the impairment. However, management remains challenging and is frequently tailored case-by-case. It is based on bottom-up (auditory skills restoration by hearing aids) and top-down procedures (hearing and speech training).Generally, a multidisciplinary approach is favored.Once the full workup is completed, two main therapeutic options may be offered. The first relies on maximizing signal to noise ratio to improve listening in noise. The second consists of sound amplification through conventional hearing aids or cochlear implant (CI).Treatment modality should be chosen following intensive counselling of the patient or the pediatric patient’s family. Clear information must be provided regarding the eventual outcome limits in the case of postsynaptic or associated CNS lesions.Signal-to-noise ratio maximizationIn milder forms of ANSD, patients may benefit from the use of “FM-listening” devices. Indeed, speech comprehension in noise is one of the main difficulties encountered by ANSD patients, even in milder forms with little audiometric threshold impact. The use of “FM-listening systems“ has been extensively described in the classroom environment. Speech is detected directly from the speaker and transmitted through radio signal to headphone receivers worn by the child, enhancing the speech signal. Positive outcomes of this device have been described in several studies , as wellAmplification: Hearing aids and cochlear implantConventional hearing aids may be proposed, although most studies report poor outcomes in the case of ANSD ,169. IndIndeed, CI appears to be an effective rehabilitation modality for ANSD patients. This may be explained by the fact that the implanted electrode delivers synchronized electrical impulses directly to the auditory nerve, bypassing the presynaptic IHCs and its synapse involved in the unsynchronized firing of the auditory nerve described in ANSD .OTOF, SLC17A8, CACNA1D, CABP2). Patients with these mutations had a significantly better outcome in speech recognition than patients with mutations in the four studied genes responsible for spiral ganglion dysfunction  [Despite this evidence, CI outcomes in speech perception remain variable. Many biographical factors  have been reported to influence CI outcomes, but account for less than 25% of their variability . In case DIAPH3) ,77.The general rules for cochlear implantation must be promoted in children with isolated forms of congenital or very early onset ANSD: early implantation must remain the standard of care in case of severe to profound hearing loss with normal cochlear nerve anatomy. Otoferlin mutations are associated with excellent CI outcomes and typically on par with individuals with genetic mutations affecting the sensory partition of the cochlea . CochleaThe concept of ANSD is based on an operational definition: speech discrimination disorders and/or abnormal language development out of proportion with sound detection abilities, as well as preserved outer hair cell responses with very disturbed ABRs. ANSD may be caused by cochlear presynaptic and postsynaptic lesions or by lesions to ascendant cochlear fibers from the auditory nerve to the brainstem. Genetic, environmental, infectious, inflammatory and idiopathic causes may trigger the symptoms since birth, during childhood or later in life. The clinical patterns of ANSD are very heterogeneous. Hearing rehabilitation is more efficient in peri-synaptic disorders thanks to cochlear implants. However, genetic studies that have proven to be essential in the knowledge of underlying mechanisms of ANSD represent a promising therapeutic approach in the management of ANSD.