The recognition of Auditory Processing Disorder (APD) as a distinct clinical condition that impacts hearing capacity and mental health has gained attention. Although pure tone audiometry is the gold standard for assessing hearing, it inadequately reflects everyday hearing abilities, especially in challenging acoustic environments. Deficits in speech perception in noise, a key aspect of APD, have been linked to an increased risk of dementia. The World Health Organization emphasizes the need for evaluating central auditory function in cases of mild hearing loss and normal audiometry results. Specific questionnaires play a crucial role in documenting and quantifying the difficulties faced by individuals with APD. Validated questionnaires such as the Children’s Auditory Processing Performance Scale, the Fisher’s Auditory Problems Checklist, and the Auditory Processing Domains Questionnaire are available for children, while questionnaires for adults include items related to auditory functions associated with APD. This systematic review and meta-analysis identified six questionnaires used for screening and evaluating APD with a total of 783 participants across 12 studies. The questionnaires exhibited differences in domains evaluated, scoring methods, and evaluation of listening in quiet and noise. Meta-analysis results demonstrated that individuals with APD consistently exhibited worse scores compared to healthy controls across all questionnaires. Additionally, comparisons with clinical control groups showed varying results. The study highlights (i) the importance of standardized questionnaires in identifying and assessing APD, aiding in its diagnosis and management, and (ii) the need to use sub-scores as well as overall scores of questionnaires to elaborate on specific hearing and listening situations. There is a need to develop more APD specific questionnaires for the adult population as well as for more focused research on APD diagnosed individuals to further establish the validity and reliability of these questionnaires. It is crucial to document and quantify these difficulties, and this can be achieved using specific questionnaires. These questionnaires are a key component in the evaluation of APD as they guide the implementation of an auditory processing test battery based on the patient’s questionnaire responses, together with their medical and neurodevelopmental history, and their specific needs and inform their management .Examples of validated questionnaires available for children with APD include the Children’s Auditory Processing Performance Scale (CHAPPS) , the FisFor adults, the questionnaires on hearing were not developed to specifically focus on APD, but they include questions directly related to difficulties in a range of auditory functions subserved by the auditory brain and associated with APD. Previous research has demonstrated that these questionnaires provide information on patient symptoms that correlate with APD tests, allowing differentiation between normal controls, individuals with hearing loss, and those with APD .The aim of the current study is to evaluate the ability of existing questionnaires on APD in children and adults to separate APD diagnosed individuals from normal controls as well as from other clinical groups with normal auditory processing.2.This systematic review and meta-analysis follows PRISMA guidelines  and was Titles and abstracts, as well as full texts, when necessary, were screened in a pair-wise manner by two independent reviewers, one senior and one younger researcher. There was no language restriction applied during the screening of titles and abstracts. However, for the full-text evaluation, only articles in languages spoken by the authors were considered. In cases where there was a conflict between the two authors regarding a specific article, a third senior author provided input to resolve the conflict and make a decision on whether to include the article.Subsequently, the resulting papers were critically appraised using the checklist for analytical cross-sectional studies , a criti2.1.For studies involving non-APD clinical and/or healthy populations as a control arm, a pairwise meta-analysis was conducted to provide a more comprehensive description and visualization of score differences in the various questionnaires between the groups. The effect size used was the standardized mean difference, expressed as Hedges’ adjusted g. The pooling of studies utilized the standard inverse variance weighting method. Considering the anticipated heterogeneity among the studies, the Der-Simonian and Laird random-effects model was consistently employed . Meta-an3.The search resulted in the identification of 1816 articles. 109 duplicates were automatically found. For each of the remaining 1707 articles, titles/abstracts were screened and 1,251 were excluded. 456 full text articles were reviewed. At the end, 12 studies with 266 unique participants with APD, 129 participants with other clinical conditions and 388 healthy controls were identified through the literature search. Studies were published from 2008 to 2020. The PRISMA flowchart is shown in Six questionnaires were found as a result of this systematic review. Five of the questionnaires  evaluated listening difficulties and other symptoms related to APD and the sixth  specifically evaluated the symptom of hyperacusis that may be present in APD. Scores in different studies are presented per examined questionnaire in The Amsterdam Inventory for Auditory Disability and Handicap (AIAD) consists of 30 questions , with a The FAPC is a pediatric checklist consisting of 25 items that assess auditory behaviors . Each unThe Speech, Spatial, and Qualities of Hearing Scale (SSQ) is a questionnaire that evaluates perceived auditory disability in complex real-life situations . It compThe HQ consists of two parts . The firThe APDQ is designed to screen for APD in children aged 7–17 years, and it can be completed by parents or teachers . The queA common aspect of all questionnaires is the dual scoring approach of one total result adding difficulties in a combined way as well as of sub-scores for different subdomains/functions of hearing and listening. Most of the publications meeting the criteria for being evaluated in this review present data for the total scoring approach alone.3.1.3.2.Comparisons of symptom severity between APD and healthy control groups, as measured by different questionnaires, are presented in 3.3.Comparisons of symptom severity between APD and clinical control groups are presented in 4.This study attempted to capture all the available evidence on the questionnaires applied on individuals diagnosed with APD to provide insights on how efficiently they separate (i) APD diagnosed individuals from normal controls and (ii) APD diagnosed individuals from other clinical non-APD individuals. Six questionnaires, published from 2008 to 2020, were identified with a total of 783 participants across 12 studies. 10 studies , 28 invoIt should be noted that most published papers report on the total scores of the questionnaires even in cases where there are sub-scores that could provide more specific information regarding hearing in quiet vs. hearing in noise or auditory attention as well as attention span. This leads to questionnaires possibly being depicted as less efficient than they really are. All questionnaires are depicted as being efficient in separating APD diagnosed individuals from normal controls with a strong effect size , while sDebate on APD , while aAs difficulty hearing in noise in the presence of normal hearing in quiet is a core APD symptom, it is essential for a questionnaire on APD to measure this and facilitate the distinction. Four out of the six questionnaires identified have separate sub-scores or elements to provide information on hearing in quiet vs. hearing in noise. However, two of them  do not have items or sub-scores for this distinction. This leads to less granular data that may separate perceived hearing sensitivity related disability vs. perceived auditory processing related disability. The remaining four questionnaires that include these data and can make the distinction are rarely represented in detail in the publications as this systematic review shows.There are some inherent limitations in this study. Answers regarding difficulties in everyday communication may be over-or underestimated by different individuals based on personality characteristics . Auditor5.A systematic review of a total of 266 APD diagnosed individuals across 12 studies shows that hearing difficulties documented on six different questionnaires are in good agreement with APD diagnosis based on psychoacoustic evaluation and separates affected individuals well from both normal controls and other clinical groups. Limited data exist on reporting questionnaires subscores corresponding to specific hearing and listening situations. Future research should focus on APD current established guidelines if we are to have more solid outcomes with larger samples as well an added focus on adults that are under-researched and possibly undermanaged.The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding authors.MS, HT-V, MP, EG, EV, SM, PR, HG, NU, AS, D-EB, and VI contributed to conception and design of the study. MS, EG, D-EB, and VI organized the database. MS performed the statistical analysis. MS, D-EB, and VI wrote the first draft of the manuscript. EG wrote sections of the manuscript. All authors contributed to manuscript revision, read, and approved the submitted version.Author MS received honoraria as a consultant or for lectures for Lundbeck and Viatris.The remaining 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.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Firefighters are exposed to extensive hazardous noise while on the job, both during routine tasks at the station and when responding to calls. However, little is known about firefighters’ occupational noise hazards. This study employed mixed methods, including focus groups, a survey, and audiometric testing, to identify sources of noise in the firefighters’ work environment, determine hearing protective strategies, discern firefighters’ perceptions of occupational noise exposure and impacts to their health, and quantify the prevalence of hearing loss among South Florida firefighters. A total of 6 senior officers served in an expert panel, 12 participated in focus groups, 300 completed the survey, and 214 received audiometric tests. Most firefighters were unaware of the risk and their departments’ policies, and did not participate in hearing protection practices and avoided using hearing protection devices, which they believed impede team communication and situational awareness. Nearly 30% of participating firefighters showed mild to profound hearing loss, a prevalence that is considerably worse than expected by normal aging alone. Educating firefighters about noise-induced hearing loss early in their careers may have significant health implications for their future. These findings provide insights for developing technologies and programs to mitigate the effects of noise exposure in the firefighting population. Recurrent or high levels of noise exposure have been shown to cause irreversible damaging effects to the inner ear, leading to noise-induced hearing loss (NIHL) and vestibular loss (NIVL). This damage is compounded over time and delayed in onset, and thus is typically not detected until it is permanent and severe. NIHL cannot be cured but it can be prevented by avoiding hazardous sounds or mitigating the impact of unavoidable hazardous sounds through hearing protection and environmental controls. NIHL has long been recognized as an occupational disease. Firefighters, who approximate 1.1 million of US workers, are exposed to recurrent hazardous noise both during routine tasks  at fire stations and when responding to emergency calls . ApproxiFirefighters’ risk for NIHL is heightened not only because of their repeated exposure to hazardous noise, but also because of their infrequent use of hearing protection devices (HPDs) ,4. FirefBeyond hearing loss, extended periods of hazardous noise exposure can also lead to a loss of balance, which poses a problem in most essential firefighting tasks. Increasing evidence demonstrates higher rates of balance impairment in other noise-exposed occupational groups, including military populations ,12,13,14Limited research has been conducted that focuses on both hearing and balance in the fire service. In addition, firefighters’ perceptions of hearing risks associated with their occupation have not been studied extensively. Therefore, this study provides new insight into the prevalence of hearing loss in the fire service and firefighters’ perceptions of both their noise exposure and their risk of hearing loss.We employed mixed methods to (1) identify career firefighters’ perceptions of occupational noise exposure and its perceived health impact, (2) determine existing use of hearing protection devices, and (3) establish the prevalence of hearing loss. All subjects consented to participate, and all research activities complied with the American Psychological Association Code of Ethics and were approved by the Institutional Review Board at the University of Miami. No incentives were provided to the participants. We used organizational recruitment strategies to contact and recruit active firefighters in Florida. Working with established fire agency partners, we were able to share recruitment flyers through fire agency listservs and social media outlets. Organizational recruiting is an effective strategy when recruiting participants who are part of an occupational group. Participants were also recruited through convenience sampling, stemming from emails sent to organizational contacts and then expanded via snowball sampling . HoweverWe conducted a meeting with fire service experts, consisting of six high-ranking officers in administration and safety, each with more than 20 years of experience, representing six South Florida fire agencies. The session was conducted at a fire department headquarters, with three experts attending in person and three remotely via video conferencing. At the meeting, we discussed firefighters’ hearing health and existing workplace policies and practices to reduce hazardous noise exposure. This session informed development of a survey and focus group discussion guide directed at high-risk firefighters. The meeting also helped establish a partnership between the participating fire agencies and our research group to address hearing health in the fire service.We conducted four online focus group sessions with participants representing five Florida fire agencies using Zoom video conferencing software (version: 5.12.9). Of the 12 participating firefighters, three had already been diagnosed with hearing loss (25% positivity rate). The participants’ ranks included firefighters, drivers, captains, and chiefs, with a mean age of 49 ± 8.6 years and a mean of 22 ± 8.2 years of experience.Following standard focus group procedures , we deveWe developed a 53-item survey, consisting of four categories: demographics (6 questions), occupational history (13), health history (23), and hazardous noise exposure in the workplace (11). Demographic data collected included respondent’s age, gender, race, ethnicity, marital status, and education. The occupational history category asked respondents about their current role in the fire service, total years of experience in the fire service, whether they had a second job, and if so, what type, and whether they had previously served in the armed forces, and if so, did they serve in a combat or war zone. The health history category inquired about respondents’ health coverage plan and history of cardiovascular disease, diabetes, and hearing problems. The hazardous noise exposure category asked about noise exposure at work, types of alarms heard at the station, duration of noise exposure during a shift, and symptoms after noise exposure, such as ringing in the ears or muffling of sounds, and/or suffering imbalance, disorientation, or vertigo (among other symptoms). Three-hundred firefighters completed the survey, including the 12 focus group participants. Prior to audiologic assessment, all participants received a visual examination of the ear canal and tympanic membrane to ensure normal anatomy and unobstructed, debris-free external canals. Hearing thresholds were measured using air-conducted pure-tones with noise-reduction insert headphones  for both ears and an MA40 portable diagnostic audiometer  calibrated to meet the American National Standards Institute standards. Hearing thresholds were obtained for test frequencies of 1, 2, 3, 4, 6, and 8 kHz in 5-decibel (dB) steps using a modified Hughson–Westlake procedure . We inclAudiologic measurements were collected onsite at local fire stations in southeast Florida. Trained research personnel performed measurements in an enclosed room that was free of interference from external noise. Noise levels were measured intermittently throughout testing to meet the ANSI/ASA S3.1-1999 (R2018) standard for maximum permissible ambient noise levels, not exceeding 45 A-weighted decibels (dBA), for audiometric testing ,23. A lip > 0.10) were eliminated sequentially until the best predictors of HPD use were identified. The coefficients of determination (R2) were obtained for each entry to determine the variables’ contribution to HPD use. We computed standardized regression coefficients to equalize measurements using different scales that allow us to determine which independent variables had the greatest effects on HPD use. We also assessed the assumptions of normality of the residuals and heteroscedasticity.We transcribed audio recordings of each focus group, and then two members of the research team analyzed all transcripts through an inductive approach to identify themes and concepts. Open-ended responses from the survey were reviewed and categorized using combinations of common strings. All categorizations were made following a consensus approach. Descriptive statistics were analyzed for the survey variables and hearing test results. Means and standard deviations for continuous variables, such as age, were calculated. Values for categorical variables were summarized as frequencies and percentages. For the survey, Pearson correlation coefficients were calculated for ordinal and continuous variables and HPD use. Chi-square analysis was conducted to explore associations between dichotomous variables and HPD use. To identify factors that influence HPD use, we conducted stepwise linear regression, where independent variables were initially entered into the multiple regression to determine their collective contribution to HPD use. The independent variables without a substantial contribution .We explored mean differences of Hearing Threshold Levels (HTLs) between ears using paired-samples t-test. Analysis of Covariances (ANCOVAs) was used to calculate differences in means of HTLs at low and high frequencies by years of experience in the fire service, while controlling for age. We used Mann–Whitney analyses to examine differences in the prevalence of hearing loss at low frequencies (1 to 3 kHz) and high frequencies (4 and 6 kHz) between groups. A The qualitative analysis revealed five major themes for understanding NIHL in the fire service. The themes included the following: (1) the lack of understanding of the damage caused by noise exposure, (2) the barriers to hearing protection use, (3) the perceived sources of hazardous noise, (4) the inadequacy in current hearing protective policies and programs, and (5) the recommendations for future hearing conservation programs. The quotations provided are representative samples of the overarching themes.Panelists reported that firefighters generally do not perceive loud noises in their work environment to be hazardous and that they are unaware of the varying sources of loud noise in the fire service. The expert panel explained that the lack of understanding of hazardous noises at work is more prevalent for early career firefighters. Mid-to-late career firefighters become aware only after experiencing hearing loss. Even though the participating fire agencies require annual screening, the panel indicated that screening alone was insufficient to reduce the risk of hearing loss. The expert panel explained that firefighters’ inability to communicate with their teams and the loss of situational awareness were the greatest barriers to HPD use. Heightened situational awareness was deemed critical for safe operations on scene. Therefore, the panel recommended that researchers should focus on hearing conservation programs for routine tasks at the station as the greatest opportunity to impact cumulative noise exposure as firefighters spend a considerable amount of their shift at the station.“Eliminating a sense or masking a sense goes against everything we teach them.”“I’d rather be deaf than dead.”Other reasons given for not using HPDs included lack of availability, not being able to use HPDs comfortably when available, and peer pressure. “Someone who wants to wear hearing protection may not do so because others on the engine aren’t doing it.”The panel listed the sources that they believed to be damaging to hearing, such as noises from hydraulic pumps, helicopters, gas leaks, and two-way radios. They also stated that drivers have right ear hearing deficiencies because of the motor’s location on the fire engine. On a day-to-day basis, two-way radios, as well as station alerting systems, are usually set at the highest volume . “The radio is always set loud and then you put it right on your ear because you can’t hear the radio with all the background noise.”“Even if you are not going on the call, you will be notified that a call is going on.”The experts provided mixed responses regarding policies for hearing protection use. Three of the six panelists indicated having policies recommending the use of HPDs in morning equipment checks. The other panelists were unsure of their agencies’ recommendations for HPD use and indicated that any current policy was mostly informal and barely followed. Furthermore, all panelists indicated that the only real effort initiated was to include hearing screening with the annual physical exam. Experts suggested implementing research on improving hearing health and training programs to increase awareness of noise risks. They identified three important actions: (1) collecting fire station noise measurements, (2) gathering evidence of progressive change to firefighter hearing, and (3) educating firefighters about NIHL early in their career. These findings provide insight into developing programs to mitigate the effects of firefighters’ noise exposure. The qualitative analysis of the firefighter focus groups revealed three major themes: (1) sources of hazardous noise exposure, (2) health consequences of hearing loss, and (3) barriers for hearing protection use.Firefighters indicated considerable noise level variability depending on the type of activity and activity location. The identified sources of the noise were unique to the fire service and included riding fire and emergency trucks with and without active sirens; operating water pumps and power tools; daily checks of personal alert safety system alarms; opening and closing bay doors; and having to shout to communicate over their radios and other environmental noise. The firefighters stated that the loudest noise exposure occurred on scene, with many competing sources of noise in the background at variable levels, while having to attend to and respond to radio and in-person communications.When asked to describe the effects of hazardous noise exposure, the participants indicated the following: suffering from ringing or buzzing in the ear, disruption of effective communication, and impaired hearing. Across the focus groups, the firefighters perceived hearing loss as an unavoidable consequence of the job. Conversely, the participants were unaware of how noise exposure may impact other aspects of health, including balance  and cogn“Balance issues would get you kicked off the truck.”All participants indicated that no formal training was provided and that no standard operating policies were in place for hearing protection use. Participants also indicated that not wearing HPDs during routine activities such as morning equipment checks posed unnecessary risks to their hearing health. However, HPDs are often not used in routine daily activities because they are generally forgotten or unavailable. Another reason was not being able to detect a threat from behind, such as a perpetrator attack. Perceptions of HPD use by the focus group participants aligned with those reported by the expert panel, that HPDs posed dangerous risks to firefighters and reduced their situational awareness on scene. Participants expressed a preference for integrating communications with safety equipment and incorporating technology that dampens hazardous noise while highlighting radio communication.“If you put stuff in your ears to protect your hearing, you are not going to hear the things you need to hear.”SD = 9.9) years, with 94% male and 6% female participants. Most (83%) identified as white, 66% were Hispanic, and 96% were college graduates or had completed some college courses. Many of the participants (90%) were career firefighters with a mean tenure of 14 years on the job (SD = 8.6). Service ranks included firefighters (32%), driver operators (20%), investigators (1%), lieutenants (15%), captains (12%), and chiefs (9%). Firefighters reported responding to eight or more calls on average per shift. A few of the participating firefighters (21%) reported having a second job while 17% reported having prior military experience. The firefighters were in overall good health with only 2% reporting a history of cardiac disease and 2% having diabetes. The socio-demographic and employment characteristics of the participating firefighters are outlined in A total of 300 firefighters representing 16 Florida fire agencies completed the survey. The mean age of the respondents was 39.1  regarding hearing damage symptoms. The most reported reasons for seeing an ENT were ear infections (8%), followed by ringing in the ear (6%), and hearing loss (5%). Ten percent reported being diagnosed with a hearing problem, with 4% having had hearing surgery on both ears, and 3% reporting use of hearing aids. Regarding vestibular health, 74% of respondents were not concerned about losing their sense of balance in the future. Three percent reported being diagnosed with vertigo.Eighty-two percent of participating firefighters reported exposure to hazardous noise at work, with 66% reporting hazardous noise exposure occurring ‘occasionally’ to ‘frequently’ in a typical work shift. Fifty-four percent of participants reported having ringing or buzzing in their ears see . AdditioFor the agencies included in our study, hearing screening is mandatory at recruitment and during firefighters’ annual physical. Even so, only 59% of participants reported ever having had a hearing test, indicating that firefighters may not be aware that their hearing was being tested. Of those who reported having received a hearing test, the majority (83%) cited employment-mandated routine care as the reason. Other reasons for taking a hearing test included the following: ringing in the ear, muffled hearing, changes to hearing, and feeling off-balance. Remarkably, 82% of all participants reported never having received information about NIHL at work, and 20% were unaware of work policies or recommendations for hearing protection use see . In our r = 0.88, p < 0.01), and both were significantly, positively correlated  with HPD use. Individuals tend to wear HPDs more frequently once they have already been diagnosed with hearing loss [p < 0.05). Notably, the highest correlation coefficient for HPD use was with frequency of ringing in the ear after hazardous noise exposure , in that participants who reported greater HPD use at work also indicated greater occurrences of their symptoms.ing loss ,26; therp < 0.05), and HPD use and firefighters’ current concerns about their hearing (p = 0.008). Greater HPD use was observed in firefighters who had been previously diagnosed with hearing loss and firefighters who expressed current concerns about their hearing. However, the association between future concerns about hearing loss and HPD use was not significant (p = 0.378). HPD use was also associated with work recommendations (p < 0.001), in that, participants who reported greater HPD use at work also indicated that their work recommended HPD use on the job. Furthermore, perceptions of a hazardous noise work environment were significantly related to HPD use, p < 0.001, such that firefighters who reported ‘occasional’ to ‘frequent’ hazardous noise exposure at work were also reporting greater HPDs use. There were also significant associations between HPD use and hearing loss diagnosis , number of hearing damage symptoms , and awareness of work policies or recommendations for hearing protection use  had significant and positive associations with HPD use. According to the coefficients and p-values, and when controlling for the other factors, significant differences were observed in HPD use: HPD use increased significantly with years in the fire service, hearing damage symptoms, and awareness of employer recommendations for HPD use. Two-hundred and fourteen of the 300 survey respondents participated in the hearing test. Participants were classified into four experience groups by years of service: (1) early career defined as less than 5 years in the fire service, (2) mid-career defined as 5–9 years, (3) experienced defined as 10–20 years, and (4) late career defined as those with 20 or more years of service. r = 0.88). However, the variance inflation factor (VIF) between age and years in the fire service for our model was 1.010, which is below the concern of collinearity raised by VIFs of 10 or above [F(3198) = 5.279, p = 0.002) and noise-sensitive, high frequencies (F(3198) = 2.661, p < 0.05), after controlling for age. The covariate, age, was significantly related to HTLs at the high frequencies (F(1198) = 8.996, p = 0.003), but not significant at the low frequencies (F(1198) = 1.281, p = 0.259). Pairwise comparisons indicate significant differences in HTLs at the low frequencies between early and mid-career firefighters (p = 0.001). Bonferroni correction was applied; thus, the effects are reported at a 0.008 level of significance.We conducted an ANCOVA to explore the relationship between HTLs and years in the fire service, while controlling for age. As previously noted, age and years in the fire service were positively, highly correlated . HTLs at the noise-sensitive, high frequencies also showed statistically significant differences between the groups, with firefighters having more severe hearing loss showing greater concern .Mann–Whitney tests were conducted to compare HTLs for the worst ear at low and high frequencies on the firefighters’ self-reported levels of concern about hearing loss. The HTLs at the low frequencies showed significant differences between those with and without current concerns about hearing loss , U = 5292, z = −2.151, and p = 0.031) and at the noise-sensitive, high frequencies . Moreover, firefighters with hearing loss at the low frequencies, who reported greater HPD use, also had more severe hearing loss at the noise-sensitive, high frequencies.Mann–Whitney tests showed that there was a statistically significant association of HPD use and HTLs at both low frequencies . Alarmingly, 58% of the participating firefighters reported other damage to the ear. Many (54%) reported having muffled hearing after noise exposure, a sign of a temporary threshold shift that often occurs following exposure to hazardous noise. Although threshold shifts often return to normal, evidence demonstrates that permanent damage to the inner ear has occurred and is linked to the early onset of hearing loss ,29,30,31Even though only 10% reported a diagnosis of hearing loss, the results of the hearing test show that, in fact, nearly 30% of the firefighters in this study showed at least mild hearing loss across low and high frequencies, indicating that firefighters may not be aware of their own hearing loss. For our analysis, we used the WHOs hearing grading system , howeverIn our study, firefighters reported a hearing damage and loss greater than expected by aging alone ,36,37. TStudies have shown that adults with NIHL are more likely to experience falls ,31,39,40Noise-induced ear damage can be prevented by wearing HPDs. Thus, operational duties in the military, fire service, and other occupations with hazardous noise exposure often require the use of HPDs. However, participating firefighters reported rarely using their HPDs, noting valid ancillary safety concerns. This is consistent with findings showing that military personnel were concerned about using HPDs because of reductions in situational awareness, interference in detection and localization of auditory cues, and because of incompatibility with other military gear . FurtherThe National Fire Protection Association (NFPA) standards for safety and health recommend that fire departments create hearing conservation programs that reduce or eliminate harmful sources of noise and require hearing protection when noise exceeds 90 decibels ,49. The A limitation of the current study is that we did not collect noise exposure profiles of the firefighters’ work environments and across job categories in the fire service. Future studies should characterize firefighters’ noise exposure by location (stations and scenes) and across job roles and activities. Furthermore, firefighter’s work environments and hearing health need to be monitored longitudinally to better understand the frequency, duration, and hazardous levels of their noise exposure, which can inform the development of mitigation strategies and allow for better estimates of hearing health risks .Firefighters’ substantial exposure to noise and associated health risks reveal a need for policies aimed at mitigating hearing health risks. Efforts are needed to integrate hearing-protective mechanisms with communication equipment and to implement more effective hazardous noise alerting systems and environmental controls. Mechanisms and controls must be widely accessible, easy-to-use, and accurate, while not compromising firefighter safety or performance. Additionally, it is important to provide training programs regarding NIHL, balance dysfunction, and the long-term impacts of hazardous noise exposure. This information, along with instructions on effective HPD use, should be included as part of the minimum standards training. Educating firefighters on these risks early in their career will likely benefit their overall hearing health. Research shows that informing workers of the health risks at entry level can change their behaviors, specifically related to risk avoidance . TherefoOur findings indicate that firefighters are at considerable risk of NIHL. Efforts are needed to minimize the incidence of hearing loss and tinnitus in firefighters. A necessary next step is to increase awareness of factors affecting hearing health and to support health-promoting behaviors—specifically, the use of HPDs and other protective strategies—when using protection does not negatively impact firefighter safety and performance. Future studies are needed to better characterize noise in the work environment and to better understand the impact of using HPDs on firefighters’ situational awareness and job performance.


Pteromalus puparum , in fighting against Beauveria bassiana . Successful colonization of B. bassiana on P. puparum adults was confirmed by scanning electron microscopy (SEM). AMPs were induced upon B. bassiana infection. The knockdown of key genes, PpTollA and PpIMD, in Toll and IMD signaling pathways, respectively, significantly compromised insect defense against fungal infection. The knockdown of either PpTollA or PpIMD in P. puparum dramatically promoted the proliferation of B. bassiana, resulting in a decreased survival rate and downregulated expression levels of AMPs against B. bassiana compared to controls. These data indicated that PpTollA and PpIMD participate in Toll and IMD-mediated activation of antifungal responses, respectively. In summary, this study has greatly broadened our knowledge of the parasitoid antifungal immunity against fungi.Insects employ multifaceted strategies to combat invading fungi, with immunity being a promising mechanism. Immune pathways function in signal transduction and amplification, ultimately leading to the activation of antimicrobial peptides (AMPs). Although several studies have shown that immune pathways are responsible for defending against fungi, the roles of parasitoid immune pathways involved in antifungal responses remain unknown. In this study, we evaluated the roles of the Toll and IMD pathways of a pupal parasitoid,  Beauveria bassiana . This fungus parasitizes over 700 insect species in 149 families and has been registered worldwide as a mycoinsecticide formulation [B. bassiana conidia adhering to the insect’s epicuticle, developing germ tubes, and colonizing the bodies of their hosts by breaking through the cuticle with the aid of degrading enzymes [Entomopathogenic fungi are viewed as effective substitutes for chemical insecticides due to their broad host range, environmental friendliness, and higher safety to non-target organisms . One of mulation . Direct  enzymes ,4.Insects have evolved various strategies to fight against fungal infection, among these the innate immune system playing a significant role in antifungal responses . Once fuThe Toll and IMD pathways are two core signaling pathways involved in the antifungal immune response ,9. TypicB. bassiana challenge and the Toll signaling pathway was strongly activated during fungal penetration stage [Spz or dorsal-related immunity factor (Dif) mutant files became more sensitive to fungal infection than wild-type files [REL1, a dorsal homologous gene, has been identified in two mosquitos and their roles in anti-B. bassiana have been affirmed [AgREL1 and AaREL1 revealed their functions in inducing the expression of antifungal peptides and increasing susceptibility to B. bassiana. Previous studies have also suggested the involvement of the IMD pathway in the antifungal response [Drosophila IMD pathway-derived AMPs were stimulated by fungal infection [Relish knockdown flies were more sensitive to natural fungal infection [caspar-mutant mosquitos since caspar could block the proteolytic activation of Relish [Transcriptome analysis has demonstrated that regulators in immune pathways can be activated upon on stage ,15. Morepe files . REL1, aaffirmed ,18. RNA response . For insnfection . Relish nfection . Silencif Relish ,22.B. bassiana, it may affect the survival rates of the parasitoid wasps [Pteromalus puparum  is a pupal endoparasitoid wasp that can parasitize numerous hosts, including more than 20 species [P. puparum genome was published previously, along with the identification of immune genes [Parasitoids are significant natural controls of their insect hosts and are considered as important agents in integrated pest management (IPM) programs. Due to the widespread pathogenicity of id wasps ,24. The  species . It can ne genes ,27, layiPpTollA and PpIMD) in the Toll and IMD pathways to investigate their roles in antifungal response. The results showed that either knockdown PpTollA or PpIMD dramatically promoted the proliferation of B. bassiana and decreased the expression levels of AMPs following fungal challenge, leading to an increase in susceptibility to B. bassiana.In this work, we silenced the key regulators (B. bassiana conidia onto P. puparum cuticle was observed using a scanning electron microscope (SEM)  . After 6pe (SEM) A. As timressoria B. Sustairessoria C,D. ThesPpTollA and PpIMD) of immune pathways upon B. bassiana infection in P. puparum adults. The expression levels of P. puparum AMPs were dramatically increased, reaching a peak at different time points after infection followed by a significant decrease as shown in PpTollA and PpIMD were elevated after infection. Dead adult wasps affected by B. bassiana were transferred to the Petri dishes containing moist filter paper to check fungal growth. P. puparum after death. The growth and sporulation of the hyphae out of the cuticle confirmed that fungal infection was the cause of death.Furthermore, we evaluated the elicitation of AMPs and key signaling molecules  significantly differed from that of other treatments   D.PpTollA knockdown parasitoids, we assessed fungal load 48 h after inoculation  compared to the control groups  was significantly shorter than that of the latter group after the B. bassiana infection (LT50 = 132.00 h), indicating that PpIMD plays an essential role in antifungal defense against pathogens in parasitoids , Ostrinia nubilalis (Lepidoptera: Crambidae), and Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) [B. bassiana on P. puparum under varied humidity levels, thereby gaining a deeper understanding of B. bassiana’s virulence towards host insects in diverse environmental conditions.The successful evasion and completion of a fungal pathogen’s life cycle on a host is highly dependent on its ability to parasitize the host epidermis . In ordemelidae) ,30,31. Tmelidae) , all theDrosophila Toll-1 acted as the elicitor of the antifungal peptide drosomycin [Spz significantly abolished drosomycin expression and reduced the host resistance to fungal challenge [Spz in regulating the mosquitoes’ survival and sensitivity to fungal challenge have also been demonstrated, where RNA knockdown of either Toll5A or Spz1C leads to a decreased expression of Spn27A following fungal challenge, thereby increasing its susceptibility to B. bassiana [Dif, dorsal, and their homologs) in fighting against B. bassiana have been revealed through gene knockdown in various insects, such as Anopheles gambiae (Diptera: Culicidae), Aedes aegypti (Diptera: Culicidae), Drosophila melanogaster (Diptera: Drosophilidae), and Spodoptera litura (Lepidoptera: Noctuidae) [Myd88, TRAF, Clip-serine proteases and their homologs, and TEPs, have also been uncovered [PpTollA, leading to a dramatic reduction in the expression levels of downstream components, including PpMyD88, PpPelle, and PpTraf, along with a reduced survival rate in P. puparum adults. Our result coordinated with previous studies and highlighted the importance of parasitoid Toll pathway in defending against B. bassiana.The Toll pathway has been considered as the primary defense mechanism against fungal invasion in insects, and much research has been conducted on the antifungal effects of immune signaling molecules involved in this pathway ,34. Valuosomycin . Mutatiohallenge . The crubassiana . The impctuidae) ,17,18,37ncovered ,39,40,41B. bassiana by PpIMD knockdown. The IMD pathway is a well-known defense mechanism against Gram-positive bacteria. Interestingly, Wu et al. [Bombyx mori (Lepidoptera: Bombycidae) apolipophorin-III, which exhibited potent antifungal effects on B. bassiana. This injection included the upregulation of BmMyd88 in the Toll pathway and the downregulation of BmTak1 in the IMD pathway, highlighting the significance of both the Toll and IMD pathway in fungal defense [Drosophila drosomycin was regulated by the Toll pathway activation in fat body and controlled by the IMD pathway in the respiratory tract [B. mori have shown that different immune pathways mediated the expression of different antifungal peptides, with the IMD pathway specifically controlling the expression of Bmenbocin 1, Bmgloverin 2, and Bmattacin 1 [PpIMD not only hindered the expression of downstream components, such as PpDredd, PpTab2, and PpRelish, but also significantly compromised the host’s defense against B. bassiana infection. These findings emphasize the vital role of the PpIMD-mediated IMD pathway in mounting an effective antifungal response.In addition, we investigated the role of the IMD pathway in resisting against u et al.  demonstr defense . Howeverry tract . Additiottacin 1 . Furtherttacin 1 . In our B. bassiana infection. Previous research indicated that defensin and abaecin were regulated by both Toll and IMD signaling pathways [PpDefensin and PpAbaecin maintained relative low transcription levels in parasitoid adults treated with either dsPpTollA or dsPpIMD in comparison to those treated with dsLuc, even under uninfected conditions. Similar observations were found in B. mori, where the disturbed Toll and IMD immune pathways using specific inhibitors resulted in reduced expression of antifungal peptides [Casparp1 displayed significantly higher levels of AMP expressions under both uninfected and infected statuses [AMPs are vital downstream products of both Toll and IMD immune pathways, directly functioning in killing microorganisms. In this study, the roles of three types of AMPs, defensin, pteromalusin, and abaecin, were investigated upon pathways . In contpathways . Our qRTpeptides . Conversstatuses . In shorP. puparum were initially collected from a cabbage field in the experimental farmland of Zhejiang University in 2012 and were reared on their natural host pupae, Pieris rapae (Lepidoptera: Pieridae), under a 14L:10D photoperiod at 25 ± 1 °C and 80% relative humidity [P. puparum wasps were reared in finger-type plastic tubes with 20% honey water (v:v). Two-day-old mated female wasps were used for parasitism. Laboratory colonies of humidity . Newly eB. bassiana ARSEF Bb2860, was used in the following experiments [The entomopathogenic strain, eriments . Fungi wP. puparum adult wasps with B. bassiana via spraying exposure assay. Before conducting the experiments, we assayed the spore germination rate of each batch of B. bassiana conidia. The viability of B. bassiana is measured by counts of germinated conidia in a 24 h liquid culture containing 2% sucrose and 0.5% peptone. Conidia with a germination rate exceeding 90% within 24 h of incubation were used for further experiments [8 conidia/mL before dilution.We inoculated eriments ,51. The 7 conidia/mL. Subsequently, the parasitoids were transferred to finger-type plastic tubes with 20% honey water (v:v). The concentration of deposited conidia was checked by counting the number of conidia/mm2 using microscopic counts from three glass cover slips placed alongside the wasps during spraying [B. bassiana infection, we collected fifteen adult wasps at each time point .To perform the experiment, the wasps were anesthetized for five minutes and carefully placed in sterile 90 mm Petri dishes. Three glass cover slips (20 × 20 mm) were also included in the Petri dish alongside the wasps. Each Petri dish with parasitoids was then subjected to either a spray of the spore suspension or a control solution (0.05% Tween-80) using a handheld Micro Ulva fogger. The spraying solution consisted of 2 mL with a concentration of 1 × 10spraying ,53. To aP. puparum wasps were used for SEM analysis. These parasitoids were fixed in 2.5% glutaraldehyde for 24 h at 4 °C, post-fixed in 1% buffer (0.1 M sodium cacodylate). Dehydration of the samples was carried out at 4 °C in acetone grades, starting from 30%, 50%, 70%, 80%, 90%, 95%, and 100%, with each grade lasting for 15 min. The dehydrated samples were then dried with tetra methyl silane for 5–10 min for two times, mounted on a stub, and then coated with gold-palladium using Q150T ES  before examination by SEM with the Hitachi Regulus 8100 .A total of 12 infected PpTollA and PpIMD on P. puparum wasps against B. bassiana, RNAi-mediated knockdown of PpTollA and PpIMD was performed along with the observation of their impact on the survival rates of these parasitoids. The complete coding sequences of PpTollA and PpIMD were obtained from our previous study [P. puparum. The amplified products were then cloned into the pBM23 Toposmart vector . The accuracy of the amplified sequences was verified by DNA sequencing. Single stranded RNAs were transcribed using MEGAscript T7 Transcription Kit  and then mixed and annealed to get double stranded RNA following the manufacturer’s protocol. After purification, dsRNAs were verified, quantified, and stored at −80 °C.To investigate the effects of us study . PrimersPpTollA or PpIMD dsRNA were injected into each yellow pupal stage of P. puparum using Nanoinject III . The dsLuc-injected parasitoid groups served as the controls. The RNA silencing efficiency was evaluated by examining the gene expression levels of randomly selected P. puparum wasps after emergence. We collected 5 parasitoid wasps in each replicate, and at least three biological replicates were conducted. Furthermore, these adult wasps were divided into two groups, one group challenged with B. bassiana and the other group challenged with sterile PBS. The B. bassiana suspension used for formal RNAi experiments consisted of a 2 mL-conidial suspension with a concentration of 1 × 107 conidia/mL. Dead wasps were recorded every 12 h post fungal challenge, and the Kaplan–Meier method was used to analyze the difference of survival rates among these RNA silencing parasitoids [Fifty nanoliters of asitoids . For the18s rRNA being used as the internal control. Fungal load abundance of RNAi groups was evaluated by analyzing the transcript abundance of B. bassiana 18s rRNA as a fungal-specific primer [All samples were homogenized in Trizol reagent following the manufacturer’s protocol. The extracted RNA was reversely transcribed into cDNA using PrimeScript™ One Step RT-PCR Kit . qRT-PCR was performed to examine the gene expression levels in the collected samples, with c primer . All theΔΔCt method. These data were presented as the mean ± standard deviation (SD) with at least three replicates. One-way ANOVA analysis and Tukey’s test were used to compare the differential gene expression levels among different time points. The student t test was used to compare the mean of two groups.The expression levels of these genes were quantified using the 2PpTollA and PpIMD, in these immune pathways are responsible for host defense against fungal infection. Silencing either of them significantly inhibited the expression of downstream effectors, compromised host defenses against fungal infections, and reduced the survival rates of parasitoids. In addition, our findings shed light on the regulation of AMP expressions in parasitoid antifungal immune responses. These results will contribute to a comprehensive understanding of insect-fungal molecular interactions and facilitate the development of more effective strategies for utilizing both parasitoids and entomopathogenic fungi in controlling fungal pathogens.Overall, our study offers a valuable understanding into the mechanisms of antifungal immunity in parasitoids through the Toll and IMD pathways. Both key genes,


Colorectal adenoma can develop into colorectal cancer. Determining the risk of tumorigenesis in colorectal adenoma would be critical for avoiding the development of colorectal cancer; however, genomic features that could help predict the risk of tumorigenesis remain uncertain.In this work, DNA and RNA parallel capture sequencing data covering 519 genes from colorectal adenoma and colorectal cancer samples were collected. The somatic mutation profiles were obtained from DNA sequencing data, and the expression profiles were obtained from RNA sequencing data.Despite some similarities between the adenoma samples and the cancer samples, different mutation frequencies, co-occurrences, and mutually exclusive patterns were detected in the mutation profiles of patients with colorectal adenoma and colorectal cancer. Differentially expressed genes were also detected between the two patient groups using RNA sequencing. Finally, two random forest classification models were built, one based on mutation profiles and one based on expression profiles. The models distinguished adenoma and cancer samples with accuracy levels of 81.48% and 100.00%, respectively, showing the potential of the 519-gene panel for monitoring adenoma patients in clinical practice.This study revealed molecular characteristics and correlations between colorectal adenoma and colorectal cancer, and it demonstrated that the 519-gene panel may be used for early monitoring of the progression of colorectal adenoma to cancer. The oColonoscopy plays an important role in the diagnosis and treatment of colorectal cancer during its formation and development . HoweverNumerous studies have explored the relationship between colorectal adenoma and colorectal cancer. By comparing the somatic mutation research of colorectal adenoma and colorectal cancer, a supervised random deep forest model was established in . In 28)28), wholPast research has improved our understanding of the natural history and treatment of colorectal adenomas and uncovered the advantages and disadvantages of general methods of detecting and removing adenomas. Although some studies have investigated colorectal adenoma and colorectal cancer based on the NGS platform, few have utilized multi-omics data. With the advancement of science and technology, improvements in risk stratification, adenoma detection, monitoring intervals, and screening have contributed to the prevention of colorectal cancer . The objFirst, 519 cancer-related genes in the NGS targeted panel—consisting of tumor oncogenes, tumor suppressor genes, and genes associated with target drugs and chemotherapy drugs—were collected from OncoKB , Cosmic 22.1First, 26 colorectal adenoma patients and 28 colorectal cancer patients were enrolled. The clinical information of these patients are listed in 2.2In total, DNA sequencing data of 26 colorectal adenoma and 28 colorectal cancer cases passed the quality control. Thus, somatic mutations were called for those samples using matched blood samples as normal. The mutations are listed in APC, TTN, MUC16, KRAS, and GATA3, and the top five most frequently mutated genes in the cancer group were TP53, APC, KRAS, TTN, and MUC16  gene. SOX9 has been reported to be positively correlated to tumor size . Differentially expressed gene (DEG) analysis was then applied to compare the expression profiles of colorectal adenoma and colorectal cancer, and DEGs are listed in KLF4) gene, encodes a transcription factor that belongs to the Kruppel family. It is involved in the differentiation process of epithelial cells and is thought to control the G1-to-S transition of the cell cycle following DNA damage by mediating the tumor suppressor gene p53. It is also associated with secretory meningioma and epilepsy. KLF4 participates in signaling pathways regulating the pluripotency of stem cells and chemical carcinogenesis - receptor activation. Another downregulated gene, MSH3, takes part in pathways of platinum drug resistance, mismatch repair, and colorectal cancer, and it is related to colorectal cancer, endometrial cancer, and familial adenomatous polyposis. FGFR1, one of the upregulated genes, encodes a protein that belongs to the family of the fibroblast growth factor receptor, which is a key factor in many cancer-related pathways, such as the MAPK signaling pathway, Ras signaling pathway, and PI3K-Akt signaling pathway.We also plotted the PCoA for our cancer and adenoma cohorts. The PCoA showed the cancer samples and the adenoma samples could be distinguished, shown in An independent RNA-seq dataset, GSE164541 containing 5 colorectal cancer samples and 5 colorectal adenoma samples was collected to confirm our DEGs. The same DEG analysis were conducted as in our dataset. 849 DEGs were found in GSE164541 and supplied in 2.7Because some genes were differentially mutated or expressed between cancer samples and adenoma samples in this study, and this observation has also been previously reported , this stFor achieving the best accuracy for the mutation profiles, 20 is the optimal gene number. The receiver operating characteristic (ROC) using 20 genes for mutation profiles is displayed in To achieve the best accuracy for the expression profiles, 20 is the optimal gene number. The ROC using 20 genes for expression profiles is displayed in We further validated the 20 gene set for expression profiles in an independent dataset. We trained a model using random forest based on the 20 genes from adenoma and cancer samples and tested the model performance on the independent RNA-seq dataset, GSE164541, which contains 5 colorectal adenoma samples and 5 colorectal cancer samples. The area under curve (AUC) of classifying the independent dataset reached 0.84 , mutation of EML4 with expression of ROS1  and mutation of EML4 and the expression of GATA1 . GATA3 encodes a protein that is important regulator to T-cell development and related to cancer  to supply adjacent normal tissue, adenoma tissue, and primary colorectal cancer tissue for each of the five patients, forming a 15-sample dataset.https://dcc.icgc.org/releases/release_26.To obtain the expression profile from TCGA, read counts of colorectal samples were downloaded from 3.2DNA and RNA were extracted from the obtained case samples. DNA was extracted from both tumor/adenoma and blood. RNA was only extracted from tumor/adenoma. The Quick DNA/RNA FFPE kit (ZYMO) was used for extraction from formalin-fixed paraffin-embedded (FFPE) sections. DNA quantification was conducted by Qubit dsDNA HS Analysis Kit (LIFE) and agarose gel electrophoresis, while RNA was quantified by Qubit RNA HS Assay Kit (LIFE) and RNA 6000 Pico Kit (Agilent). The construction of DNA and RNA libraries was accomplished using the ABclonal Rapid DNA Lib prep kit and KAPA Stranded RNA-Seq Kit with RiboErase HMR, according to the manufacturer’s protocol. Covaris s220 was used to physically cut 50–200-ng DNA, followed by A-tailing, adaptor ligation, and polymerase chain reaction amplification. The total amount of DNA and RNA libraries was 500 ng, and the mixing ratio was 10:1. The mixture was hybridized at 65°C for 16–18 h using hybridization probes from Boke, followed by the use of M270 streptavidin beads for 45 min for capture. Then 15 post-capture amplification cycles were carried out to obtain the captured library.3.3All samples were sequenced using a panel-based NGS system that contained 519 cancer-related genes and covered 1.8 Mb of the human genome (GRCh37/hg19) (see 3.4https://github.com/umich-brcf-bioinf-projects/microraptor) pipeline, which is based on GATK, was used to call somatic mutations. Trimmomatic was used to filter low-quality reads, and BWA mem was used for the mapping of reads. GATK SortSam, MarkDuplicates, CollectHsMetrics, BaseRecalibrator, ApplyBQSR, AnalyzeCovariates, CollectSequencingArtifactMetrics, Mutect2, GetPileupSummaries, CalculateContamination, FilterMutectCalls, and FilterByOrientationBias were used for mutation calling and filtrations.Mutations shown in matched blood samples were taken as germline mutations. The Microraptor  was used for quantification of gene and isoform abundance estimation according to TCGA GAF 2.1 files using default parameters.3.8To eliminate the batch effect, we used the combat function from sva package  for batc3.9The dissimilarities between samples was first calculated using Bray-Curtis dissimilarity distance measure using vegdist function from vegan package . cmdscal3.10DEG analysis was performed using R package DESeq2 . Wald si3.11We employed the R function phyper to determine the significance of overlap between two sets of differentially expressed genes (DEGs). In our study, the parameters q=17, m=151, n=20827, and k=849 were used to define the size of each set and the level of overlap.3.12Before classification, the expression data, the read counts were normalized for each sample. For mutation data, the mutation counts on each gene were used as features.For gene selection, the scikit-learn package  was usedFor classification, we implement a 100-estimator random forest classification model with the same hyperparameters. The reason we chose random forest as the classification algorithm is that (a) each tree of random forest process a random subset of features and samples, alleviating the problem of overfitting; (b) the ensemble of trees could alleviate the curse of dimensionality.3.13The gene mutation profile was processed by indicator function, which will output whether the gene has mutation (output = 1) or not (output = 0). To decrease false discoveries, genes that mutated in less than 5 samples were excluded. Pearson correlation from scipy package  was used4APC, TTN, MUC16, and KRAS genes were high in frequency in both colorectal adenoma and colorectal cancer samples. However, some differences were identified, such as the relatively high occurrences of mutations in SOX9 and ARID5B in the colorectal adenoma samples, and the relatively high mutation frequencies of TP53 and SPTA1 in the colorectal cancer samples.In this study, 54 FFPE samples were collected from patients with colorectal adenoma or colorectal cancer as well as the matched blood samples to explore the molecular characteristics of colorectal adenomas and the relationship to colorectal cancer. P-Cap was employed to capture DNA and RNA simultaneously, and the NGS results were analyzed. Mutations of the GNAQ and KRAS were identified as driver genes in both colorectal adenoma and colorectal cancer samples. GNAQ was a potential driver in colorectal cancer. The mutated GNAQ gene is a proto-oncogene of uveal melanoma, and the activation of the pathway containing the mutated GNAQ may be the main cause of uveal melanoma  can be found below: This study was approved by the Ethics Committee of Peking Union Medical College Hospital , the Ethics Committee of Shanghai Changhai Hospital  and the Ethics Committee of NanFang Hospital of Southern Medical University . The participants [legal guardian/next of kin] provided written informed consent to participate in this study. The patients/participants provided their written informed consent to participate in this study.GT, ZL, and YB conceived the project. PP, JL, and XL implemented the experiments. BW, CX, and YH analyzed the data. XS, HY, and LFC prepared the figures. XT, HW, and LYC prepared the data and performed literature search. PP, JL, and BW wrote the manuscript. All authors contributed to the article and approved the submitted version.


Background: The persistent stapedial artery (PSA) is a rare congenital vascular malformation involving the middle ear. It is usually associated with pulsatile tinnitus and/or conductive hearing loss and can account for multiple risks during middle ear surgery. Case Report: we present a case of a 9-year-old male child with conductive hearing loss and persistent stapedial artery in his right ear, who was admitted to our ENT Department for hearing loss. During surgery, we discovered PSA along with congenital stapes agenesis and oval window atresia, as well as an abnormal trajectory of the mastoid segment of the facial nerve. After ossicular reconstruction  with cochleostomy, no surgical complications were recorded and hearing improvement was monitored by pre- and postoperative audiometry. Conclusion: Stapedial artery is a rare anatomical middle ear abnormality that can prevent proper surgical hearing restoration and can be associated with other simultaneous temporal bone malformations.  The persistent stapedial artery (PSA) is a rare vascular congenital abnormality originating from the second aortic arch, with a prevalence of 0.02–0.48% 5 out of 1045) as a temporal bone study shows [045 as a PSA varies anatomically and among the known types there are described: the hyoido-stapedial artery, the pharyngo-stapedial artery, the stapedial artery with aberrant carotid artery and the pharyngo-hyo-stapedial artery, with the first type being the most described in literature. It is often an incidental discovery (discovered on CT scan images or intraoperatively during middle ear surgery), as it is mostly asymptomatic. It can also be associated with tinnitus, conductive hearing loss , unilateral or bilateral pulsatile tinnitus or even dizziness or vertigo . SensoriGiven the anatomical variations of PSA and its trajectory through the middle ear, the surgeon must consider the risk of facial palsy, hearing loss, hemiplegia and account for the possibility of an aberrant internal carotid artery which can emerge in the hypotympanum without bone protection and can be easily injured during middle ear exploration . Still, The golden standard for diagnosing PSA is computed tomography (CT) scan which displays the absence of foramen spinosum and the abnormal widening of the anterior fallopian canal. Angiography, magnetic resonance angiography (MRA) or magnetic resonance imaging (MRI) scan are the only imaging tests which could specifically exhibit the artery and they might prove useful only in selected cases if one considers the variable diameter of this vessel (0.4–2 mm) .We report a case of persistent stapedial artery associated with other rare middle ear malformations in a paediatric patient; informed written consent from the child’s parents and approval from the Hospital’s Ethics Committee were obtained .We present the case of a 6-year-old male child who was first examined in our Department for bilateral hearing loss. From history, the child was born by vaginal delivery, on term, and had no past medical problems. We also made the diagnosis of bilateral mixed hearing loss, with an air-bone gap (ABG) of 35 and 40 dB at 1000 Hz, respectively, and normal bilateral type A tympanogram . As suchNo family history of hearing problems could be elicited. A high resolution CT scan revealed bilateral middle ear anomalies. There were no images of the oval window and stapes suprastructure in his left ear, with abnormal facial nerve canal position and patent foramen spinosum . The staThe middle ear exploration of the right ear discovered a bright red pulsatile vessel across the promontory, in a cranial to caudal position, covering the round window and associating the absence of the stapes and the oval window. The diagnostic of persistent stapedial artery (PSA) was made, which resulted in postponing the right ear ossicular chain reconstruction. During the following 3 years the child underwent surgical approaches for his left ear hearing loss. Stapes agenesis, but with oval window presence were recorded, with no associated PSA on that side. A stapedotomy and a Teflon wire piston attached to the incus were performed for reconstruction of the ossicular chain. This was followed by two other consecutive ossicular chain release surgeries, due to recurrent bony fixation of the incus and malleus to the middle ear walls, as observed intraoperatively. Hearing in the left ear had later degraded, as the monitoring audiograms showed, with minor improvement of the ABP persisting on long term follow-up (from 51.6 dB preoperatively to 41.6 dB after surgery). Hearing loss in patient’s right ear (with PSA) was addressed by performing an ossiculoplasty with a total ossicular replacement prosthesis (TORP). After a thorough preoperative planning based on prior surgical middle ear exploration and CT imaging, a transcanalar approach to the middle ear was used. A standard tympanomeatal flap was raised and the PSA was inspected. Large dimensions, complete coverage of the oval window site and crossing over the round window niche were again noted . The PSAThe patient reported immediate postoperative good hearing but failed to present at our Department for performing an audiogram. His hearing was firstly evaluated at 2 months after right ear surgery demonstrating an air-bone gap of 41.6 dB (from 56.6 dB preoperatively). We could not explain at that moment the results but, at 9 months after surgery we were able to have another CT scan performed. The imaging showed good positioning of the ossicular prosthesis . WithoutFuture surgical alternative approaches were contemplated in this case for hearing rehabilitation, considering the presented abnormalities, and the patient has been planned for osseointegrated implant surgery (OSIA).PSA is a rare condition of the middle ear, with an estimated incidence of 0.02–0.5%, discovered mostly incidentally, thus creating a great impact on surgeons who can be forced to discontinue interventions, such as Govaerts et al. show in their paper . It evolves during embryologic stages from the hyoid artery, a branch of the external carotid artery which derives from the pharyngeal artery in the second aortic arch . It runs2 laser or simply avoiding it when possible. In our presented case, the large diameter of the vessel (possibly favored by stapes absence) prevented us from trying to coagulate or manipulate it, thus avoiding a high-risk bleeding that would have made the intervention impossible to be continued or extend it beyond its rehabilitation purposes. The absence of the stapes and the oval window, which would have oriented us towards a stapedotomy, forced us to perform a cochleostomy, while avoiding PSA trajectory.Understanding the embryological development of PSA can increase the confidence of handling it, either by cutting or coagulating it with COThe multitude of divisions of the stapedial artery pave the way for multiple anatomical variations of the PSA. Apart from this variety of anatomical disposals, literature review demonstrates that PSA is often associated with other middle ear structure deviations, like stapes footplate ankylosis ,11, malfPreoperative CT imaging of middle ear surgery patients is mandatory and careful interpretation of the results can sometimes prevent accidental injuries brought to a PSA. The usual findings are a small, abnormal, canaliculus leaving the carotid canal or the facial nerve, a straight line structure crossing over the promontory, an unusual widening of the fallopian canal or a different canal parallel to it between the geniculate and the oval window niche and absence of the foramen spinosum . Our CT Even if there are many reports on CT findings and embryologic explanations on persistent stapedial artery, there are few literature data regarding the main surgical approaches to the persistent stapedial artery, as this can be an incidental CT or intraoperative finding complicating middle ear surgery or cochlear implantation, always a great dilemma to the surgeon, who must decide whether to abort or complete the procedure and how to manage the PSA. Successful surgical implantation in the presence of PSA has been described by some authors , also reBeing sometimes asymptomatic, the act to manipulate the PSA or avoid it is a decision each surgeon has to take during intervention, based on the patients’ needs and considering the significant risk of permanent hemiplegia, facial nerve paralysis, tabes dorsalis-like symptoms, and hearing loss, even if multiple papers describe successful discontinuations of the artery, as well. Carefully preparing of the surgery cannot rule out the possibility of misinterpreting the presence of the PSA but certain anatomical aspects of the CT imaging specific to the PSA can warn the surgeon of such possible malformation of the middle ear, thus making the approach more cautious. Considering our case once again, we could try stapedial artery coagulation but with the risk of neurologic damage or impossibility to achieve useful hemostasis. That would have also incured the presence of a normal oval window, in order to use it for TORP reconstruction. In our case, no such structure existed, leaving just the cochleostomy option as the only approach. We can also mention that the inferior traject of the stapedial artery partially covered the round window niche. Its presence and free movement is also important to consider when functional reconstruction is the target.PSA is a rare disease, sometimes difficult to diagnose before surgery, even with imaging. Middle ear surgery in the presence of a PSA is possible without any major complications, but the surgeon alone must decide whether to manipulate the artery from its bed or to coagulate it. High resolution CT imaging is a good tool to assess the possibility of any middle ear associated abnormalities. Dimension of the artery is the main risk factor for final surgical outcome and intraoperative complications. Cochleostomy and ossicular chain reconstruction could represent an effective approach to managing hearing loss in cases with PSA. Different possible types of ossicular chain replacement prothesis could eventually yield better results, in terms of hearing restoration.


To screen the COL1A1 and COL1A2 gene mutation sites in a family with type I osteogenesis imperfecta (OI)/hearing loss and analyze the characteristics and recovery of hearing loss in patients with osteogenesis imperfecta.The basic clinical data of OI proband and her parents were collected, and the COL1A1 and COL1A2 genes were detected in peripheral blood by PCR amplification and generation Sanger sequencing. Literature of stapedial surgery in patients with osteogenesis imperfecta was collected.The heterozygous mutation of the 26 exon c.1922_1923 ins C in the OI progenitor COL1A1 gene led to the amino acid frameshift mutation of p.Pro 601FS, which was not detected in the phenotypic parents. The homozygous of exon 28 c.1782>G in COL1A2 was detected in the proband and her parents, resulting in changes in the protein p.Pro 549Ala.The clinical symptoms of the OI proband is caused by heterozygous mutation of the 26 exon c.1922_1923 ins C in COL1A1 gene. Stapedial surgery can provide short-term and long-term hearing benefits for OI patients with hearing loss.Level 4. Therefore, we identified a novel mutation locus in COL1A1 by genetic testing of OI patients and summarized the current status and prognosis of hearing loss studies in OI patients, with the aim of providing some help in the diagnosis and treatment of OI patients with hearing loss.3, PTH, thyroid function, gonadal six items , blood calcium and phosphorus.The proband, a 38-year-old woman who complained with progressive right hearing loss and tinnitus for 30 years and her parents (non-inbreeding) were brought into the study. Clinical characteristics and laboratory examinations were collected, including height, weight, scleral color, hearing, tooth condition, fracture history, bone mineral density, X-ray of the fracture site, 25-(OH) DPeripheral blood Deoxyribonucleic Acid (DNA) samples were collected, and DNA was extracted by DNA Kit from TIANGEN BIOTHECH (DP348), all exons of COL1A1 and COL1A2 were sequenced by Polymerase Chain Reaction (PCR) amplification and generation Sanger sequencing using the kit. The results were compared with the public database, and the pathogenicity was tested by Mutation Taster, Polyphen2 and SIFT online prediction software.The proband suffered from asthma, high blood pressure, multiple cavities, and recurrent limb fracture for three times previously. Physical examination found bilateral blue sclera , the norA stapes surgery with otomicroscope under general anesthesia was performed. The soft Incudomalleolar joint, fixed stapes foot plate and slender stapes crura were found intraoperatively which was the same to the previous findings. The incudostapedial joint as well as the anterior and posterior arches of the stapes were disconnected, and the Piston was implanted to reconstruct the ossicular chain. Postoperative hearing (8 months after the surgery) was significantly improved. The air-bone gap was decreased from 45 dB to 8 dB. There was a slight increase in the sensorineural threshold after the surgery, which was thought be the natural progress or the measuring error.Peripheral blood samples were collected from the proband and her parents for DNA detection of all exons of COL1A1 and COL1A2 by PCR amplification and Sanger sequencing by kit , and NM000088 and NM000089 were used as reference sequences respectively. The results showed that the proband had a heterozygous mutation of c.1922_1923 ins C in exon 26 of the COL1A1 gene, leading to the change of p.Pro 601 fs protein , which wWe report a novel missense mutation c.1922_1923 insC p.Pro 601 fs in COL1A1 in an OI proband, which is not present in the asymptomatic parents. The mutation was predicted to be pathogenic. This frameship-mutation is of great significance, since the first 601 amino acids are fixed, but the subsequent amino acids have changed and may generate a new reading frame, thus expressing a completely different protein. 1782>Gp.Pro 549 ala homozygous mutation of COL1A2 is found in all three subjects. Given that the parents have no clinical symptoms of OI and the mutation site is predicted to be “neutral”. Therefore, we believe that the clinical symptoms of OI proband may not be related to the c.1782>Gp.Pro 549 ala mutation in exon 28 of COL1A2, but the c1922incC p.Pro 601 fs mutation in exon 26 of COL1A1. This discovery enriches the gene pool of congenital osteogenesis imperfecta and provides a scientific basis for prenatal diagnosis.There have been a large number of clinical studies on the epidemiology, type, severity and treatment of hearing loss in OI patients, but there is no unified conclusion at present, and the treatment is to reconstruct the sound transmission and sensory system by surgery. It is generally believed that HL in OI patients occur mostly in the second to fourth decade of life and tends to stabilize after the age of 50.Most patients with ABG can benefit from the stapes surgery. Fixation, thickening, easy fragility of the stapes foot plate, fracture, and atrophy of the stapes crura, bleeding and thickening of the middle ear mucosa, and atresia of the oval window can be found in the temporal bone of OI/hearing loss . This paOur study finds a novel mutation site c.1922_1923 ins C in COL1A1 causing osteogenesis imperfecta/hearing loss. Stapes surgery leads to a significant improvement in hearing thresholds and reduction in ABG. Patients with hearing loss in OI can obtain short-term and long-term benefit from the stapes surgery.This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.This study was approved by the Administration Committee of Peking University People’s Hospital, China (2021-278).Ethical approval to report this case was obtained from the Administration Committee of Peking University People’s Hospital, China.Written informed consent was obtained from the patients for their anonymized information to be published in this article.The authors declare no conflicts of interest.


A relatively loud sound is audible when a vibrator is attached to the aural cartilage. This form of conduction is referred to as cartilage conduction (CC). In Japan, a new type of hearing aid has been developed using CC and has been available in clinical practice since 2017. A clinical study conducted prior to its launch demonstrated its benefits, particularly in patients with aural atresia who were unable to use air conduction hearing aids. Several studies have been published on the benefits of CC hearing aids since their introduction into clinical practice. Most of the patients included in these studies had canal stenosis or aural atresia, and the purchase rates of CC hearing aids in these patients were relatively high. However, the number of patients with canal-open ears was small, with overall poor results in the trials, with the exception of patients with continuous otorrhea. CC hearing aids are considered a good option for compensating for hearing loss in ears with canal stenosis or atresia in both bilateral and unilateral cases. However, CC hearing aids are not currently considered the first choice for patients with a canal-open ear. Sound is generally delivered to the ear via air conduction (AC) in conventional hearing aids. AC hearing aids amplify signals to help patients with various hearing losses. Unfortunately, some patients are unable to receive adequate benefits from AC hearing aids. For instance, in patients with aural atresia, hearing aids cannot be worn owing to anatomical issues or they receive inadequate benefits even if they can be worn . In addiWhen a vibrator is attached to the aural cartilage, hearing is significantly improved compared with that in the unattached condition. This phenomenon was confirmed by using a probe microphone . PreviouCC hearing aids are new hearing devices utilizing CC ,17,18. CThe initial prototype CC hearing aid was a box type, and the transducer was not compact ,17. FurtCommercially available CC hearing aids are small BTE hearing aids, which were developed based on those used in clinical studies. The main body was designed based on that used in commercially available receiver-in-canal (RIC)-style AC hearing aids. The vibrator is connected to the main body with a wire that encapsulates the electrode within. Three types of vibrator units  are employed . The sizTwo CC hearing aid  models are commercially available . The traCC hearing aids were newly devised and first launched in Japan in 2017. To date, no clinical data are available concerning CC. To determine the indications, a clinical survey was conducted in 2019. Nine medical institutions participated in the study, and 256 patients were registered . In totaIn addition to the abovementioned clinical surveys, several medical institutions have reported the results of CC hearing aid fittings. Sakamoto et al. evaluated the benefits of CC hearing aids in children with unilateral congenital atretic ears and reported that the speech recognition scores improved in noisy environments as well as with the FM system . The autNishiyama et al. assessed the efficacy of CC hearing aids in adult patients with hearing loss and with various anatomical ear canal conditions to identify suitable candidates for CC hearing aids . They caTakai et al. fitted CC hearing aids in 41 patients, 19 (65.9%) of whom purchased them after the trial . They coSeveral studies have reported the benefits of CC hearing aids in clinical practice in Japan. Most patients who attempted to use CC hearing aids experienced canal stenosis or aural atresia. The audiological benefits in these cases were significant, and the reported purchase rates were good. Patients with unilateral canal stenosis or aural atresia rarely used amplification devices before the CC hearing aid trial. However, the purchase rates of CC hearing aids in these cases were comparable to those in bilateral cases . No signCC hearing aids are currently used solely in Japan in clinical practice and cannot be purchased in other countries. However, clinical studies have already been conducted in two countries. In Indonesia, Suwento et al. measured the benefits of CC hearing aids in ten patients (aged <20 years) with microtia and aural atresia whose hearing dysfunction did not improve after ear reconstruction surgery . They foConsidering the effectiveness of CC hearing aids in the atretic ear, the difference between the benefits of BC devices and CC hearing aids is an interesting subject. In the United States, Nairn et al. compared the benefits of BC devices  and Ponto 4 ) and CC hearing aids (HB-A2CC) using a crossover study design . SixteenCC hearing aids are effective in the atretic ear, and most patients purchased them after the trial. From the viewpoint of signal transmission, the pathway to the cochlea in the atretic ear is quite different from that in the normal ear. The cartilage–AC predominantly contributes to hearing in normal ears. However, both direct and cartilage–AC pathways are absent in the atretic ear. Theoretically, the signal transmission pathway should include the skull bone in the atretic ear for conduction. Thus, the predominant pathway to the cochlea switches from cartilage–AC to cartilage–BC in the atretic ear B. The trAn absent ear canal can occur due to congenital anomalies, as well as acquired factors such as inflammation, injury, and surgical treatment. In the latter case, the ear canal is usually closed with no bony tissue, and signals delivered to the cartilaginous tissue travel via the fibrotic tissues to drive the remaining ossicles when fibrotic tissues are connected to the remaining ossicles (fibrotic tissue pathway) C. SignalOne benefit of binaural hearing is sound localization. Patients with bilateral aural atresia often exhibit poor sound localization due to BC features . However, most patients using CC hearing aids have reported improvements. Nishimura et al. evaluated sound localization by using eight loudspeakers positioned in a full-circle at 45 degree intervals in patients with bilateral aural atresia . They coKitama et al. measured the sound localization in patients with unilateral atretic ears using a CC hearing aid, BAHA, and ADHEAR on the atretic ear. Compared with the un-aided condition, no significant improvement was observed in any of the three aided conditions . HoweverEsthetic problems are considered a disadvantage of hearing devices. Compared to BC hearing aids, CC devices are smaller and a headband is not required for fixation. Unfortunately, CC hearing aids are not devoid of esthetic problems, despite the esthetic advantages in comparison with BC hearing aids. Congenital aural atresia is often accompanied by microtia, which also causes esthetic problems. Nishiyama et al. developed an auricular prosthesis incorporating a cartilage conduction hearing aid (APiCHA) to achieve the challenging goal of simultaneously improving both esthetic problems . CompareCC hearing aids were launched in Japan in 2017. The number of clinical cases in which this new device has been used has increased greatly, with several studies reporting its benefits. According to the results, CC hearing aids are considered a good option for compensating for hearing loss in ears with canal stenosis or aural atresia in both bilateral and unilateral cases. However, CC hearing aids are not currently considered the first choice in patients with a canal-open ear. Nevertheless, they can provide significant benefits in specific cases, such as continuous otorrhea. Further studies are warranted to clarify the indications for use in canal-open ears.