Prevalence of hearing protection use and subjective auditory symptoms among Spanish classical orchestral musicians.

INTRODUCTION: Sensorineural hearing loss caused by exposure to noise is one of the most frequent causes of deafness. Professional musicians have significant occupational exposure to high levels of noise. Use of hearing protection among musicians could substantially prevent hearing damage, though the rate of use is quite low. METHODS AND MATERIAL: A questionnaire on the use of protective hearing devices, hearing care, and subjective judgments of hearing difficulties was completed by a group of classical musicians from Spain. We analysed the frequency of device use by instrument based on contingency tables analysed by χ2 tests. RESULTS: One hundred and ninety-four Spanish classical orchestral musicians voluntarily completed the questionnaire. The percentage of musicians who reported using hearing protection in our survey was very low and varied with the type of instrument played. However, we found a high prevalence of subjective auditory disorders within this group. CONCLUSION: Few Spanish musicians use hearing protection. Training on hearing-loss prevention in this field and better protective devices could increase device use and improve the auditory health of this group.

Prevalence of hearing protection use and subjective auditory symptoms among Spanish classical orchestral musicians / Prevalencia del uso de protección auditiva y síntomas auditivos subjetivos entre los intérpretes de orquesta de música clásica españoles

Introduction: Sensorineural hearing loss caused by exposure to noise is one of the most frequent causes of deafness. Professional musicians have significant occupational exposure to high levels of noise. Use of hearing protection among musicians could substantially prevent hearing damage, though the rate of use is quite low.Methods and materialA questionnaire on the use of protective hearing devices, hearing care, and subjective judgments of hearing difficulties was completed by a group of classical musicians from Spain. We analysed the frequency of device use by instrument based on contingency tables analysed by χ2 tests.ResultsOne hundred and ninety-four Spanish classical orchestral musicians voluntarily completed the questionnaire. The percentage of musicians who reported using hearing protection in our survey was very low and varied with the type of instrument played. However, we found a high prevalence of subjective auditory disorders within this group.ConclusionFew Spanish musicians use hearing protection. Training on hearing-loss prevention in this field and better protective devices could increase device use and improve the auditory health of this group. (AU)

Introducción: La hipoacusia neurosensorial motivada por la exposición al ruido es una de las causas más frecuentes de sordera. Los músicos profesionales tienen una exposición ocupacional significativa a los altos niveles de ruido. El uso de protección auditiva entre los músicos podría prevenir sustancialmente el daño auditivo, aunque su tasa de utilización es bastante baja.Métodos y materialUn grupo de intérpretes de orquesta de música clásica españoles completó un cuestionario sobre el uso de dispositivos de protección auditiva, cuidados auditivos, y opiniones subjetivas sobre las dificultades auditivas. Analizamos la frecuencia del uso de dispositivos por instrumento basada en tablas de contingencia analizadas mediante pruebas χ2.ResultadosCiento noventa y cuatro intérpretes de orquesta de música clásica españoles completaron el cuestionario voluntariamente. El porcentaje de músicos que reportaron el uso de protección auditiva en nuestra encuesta fue muy bajo, y variable dependiendo del tipo de instrumento interpretado. Sin embargo, encontramos una alta prevalencia de trastornos auditivos subjetivos dentro de este grupo.ConclusiónPocos músicos españoles utilizan protección auditiva. La formación sobre prevención de hipoacusia en este campo y la mejora de los dispositivos protectores podría incrementar el uso y mejorar la salud auditiva de este colectivo. (AU)

Attitudes to noise in young adults and associated factors: adaptation of the youth attitude to noise scale into Spanish using item response theory analysis.

OBJECTIVE: This study aimed to identify the attitudes to noise in young adults and the possible effects of gender, age, and a positive history of auditory symptoms related to recreational noise exposure on the attitudes to noise in this population. DESIGN: The Youth Attitude to Noise (YANS) and the hearing symptom description (HSD) scales were adapted into Spanish to be used with young adults. The validity was determined using factor analyses and Item Response Theory (IRT) models. Linear regression models were used to determine whether the YANS scores were associated with gender, age, and auditory symptoms. STUDY SAMPLE: Both instruments were given to a sample of 728 Chilean young adults. Data obtained from this sample was used to determine the YANS and HSD scales' validity and to assess the effects of gender, age, and auditory symptoms on attitudes. RESULTS: Our results showed that the YANS and HSD scales had adequate validity and reliability. Differences in the items' capacity to discriminate attitudes to noise were noted using the IRT model. Auditory symptoms were significantly associated with the YANS scores. CONCLUSIONS: The attitudes to noise in Chilean young adults are influenced by self-perception of auditory symptoms, age, and gender.

Field assessment of acute auditory responses to environmental exposures in close quarters tactics training.

OBJECTIVE: The purpose of this study was to evaluate auditory performance of military instructors as part of a training course involving noise and blast exposure. Boothless audiometry was used to estimate the test-retest reliability of the auditory measures under realistic field conditions and to determine risk of acute auditory injury during standard training practices. DESIGN AND STUDY SAMPLE: Thirteen U.S. Marine instructors participated in study activities. An audiologic testing suite embedded in a noise-attenuating headset was used to test various tone detection tasks on subjects after exposure. Acoustic exposures were captured with sound level meters. RESULTS: Boothless audiometry provide highly repeatable results for various tests of auditory performance in the field environment. In this test population, changes in auditory performance pre- and post-noise exposure were minimal for most measures. The notable exception was binaural (NoSπ) tone detection, which showed significant degradations both as a function of pre- and post-noise exposure on the same day and as a result of cumulative noise exposure over the period of the study. CONCLUSIONS: Study outcomes are consistent with prior laboratory and epidemiological work and suggest a link between the binaural processes required for NoSπ detection and the hearing-related issues reported by blast-exposed service members.

Mhealth hearing screening for children by non-specialist health workers in communities.

OBJECTIVES: To compare outcomes of a community-based hearing screening programme using smartphone screening audiometry operated by specialist (School Health Nurses - SHNs) and non-specialist health workers (Community Health Workers - CHWs) in school children. DESIGN: This study used a two-group comparison of screening outcomes as conducted by SHNs and CHWs using smartphone screening for children in communities. STUDY SAMPLE: The study included 71 CHWs and 21 SHNs who conducted community-based hearing screening on 6805 children. One thousand one hundred and fifteen hearing screening tests were conducted by the CHWs and 5690 tests by the SHNs. RESULTS: No significant difference in screening outcome was evident between CHWs and SHNs using a binomial logistic regression analysis considering age, test duration and noise levels as independent variables. Final screening result was significantly affected by age (p < 0.005), duration of test (p < 0.005) and noise levels exceeding at 1 kHz in at least one ear (p < 0.005). Test failure was associated with longer test duration (p < 0.005; B: 119.98; 95% CI: 112.65-127.30). CHWs had significantly (p < 0.005) longer test durations (68.70 s; 70 SD) in comparison to SHNs (55.85 s; 66.1 SD). CONCLUSION: Low-cost mobile technologies with automated testing facilitated from user-friendly interfaces allow minimally trained persons to provide community-based screening comparable to specialised personnel.

Does person-centred care improve outcomes for musicians fitted with hearing protectors?

Objective: To reduce the risk of hearing injury, musicians are often recommended custom-made musicians' hearing protectors (MHP). Studies report benefits of use however, many still report challenges leading to relatively low uptake and inconsistent usage. Person-centred approaches to health have been shown to improve patient outcomes, and these principles may be translatable to musicians' hearing care. The aim was to investigate if use of, and satisfaction with, MHP is influenced by the treatment delivered to musicians by audiologists.Design: Participants were randomly allocated to one of four conditions that varied in extent of person-centred care.Study sample: Forty-two musicians with an interest in purchasing MHP were recruited.Results: Satisfaction with MHP was high overall and users reported a reduction in incidence of tinnitus. Participants reported few issues related to sound quality, however insertion difficulty was the main problem reported. Only one musician self-identified the need for alterations to their MHP.Conclusions: Adoption of person-centred approaches to MHP was not found to increase likelihood of use, however, satisfaction was high across all conditions. Most often, the need for MHP alterations were clinician-identified during fitting appointments or follow-up contact, underscoring the importance of including these components when providing audiological services to musicians.

Population-based age adjustment tables for use in occupational hearing conservation programs.

Objective: In occupational hearing conservation programmes, age adjustments may be used to subtract expected age effects. Adjustments used in the U.S. came from a small dataset and overlooked important demographic factors, ages, and stimulus frequencies. The present study derived a set of population-based age adjustment tables and validated them using a database of exposed workers.Design: Cross-sectional population-based study and retrospective longitudinal cohort study for validation.Study sample: Data from the U.S. National Health and Nutrition Examination Survey (unweighted n = 9937) were used to produce these tables. Male firefighters and emergency medical service workers (76,195 audiograms) were used for validation.Results: Cross-sectional trends implied less change with age than assumed in current U.S. regulations. Different trends were observed among people identifying with non-Hispanic Black race/ethnicity. Four age adjustment tables (age range: 18-85) were developed (women or men; non-Hispanic Black or other race/ethnicity). Validation outcomes showed that the population-based tables matched median longitudinal changes in hearing sensitivity well.Conclusions: These population-based tables provide a suitable replacement for those implemented in current U.S. regulations. These tables address a broader range of worker ages, account for differences in hearing sensitivity across race/ethnicity categories, and have been validated for men using longitudinal data.

Noise exposures of sugar cane mill workers in Guatemala.

Objective: To describe personal noise exposure measurements obtained on Guatemala sugar cane mill workers as a function of job category.Design: This is a descriptive evaluation of existing data.Sample: The data set included 51 representative noise dosimetry surveys utilising NIOSH sampling protocol, completed on workers performing 21 jobs in a Guatemalan sugar cane mill. Results: Noise doses ranged from a low of 50.9% to an extreme of 25174%. The highest observed mean noise doses were for evaporator cleaners (15761%) and juice extractors (2047%). Ninety percent of noise dosimetry samples were between 50% to 1200% dose. Annual noise exposures are also reported after considering the 7-month seasonal work schedule.Conclusions: The majority of sugar cane mill workers were exposed to hazardous occupational noise exceeding the Guatemalan permissible exposure limit (GMLSW), which is consistent with U.S. NIOSH recommended exposure limit of 100% noise dose (85 dBA time-weighted average). Consequently, the majority of workers should be enrolled in a hearing conservation programme including engineering noise control in order to prevent long-term adverse effects on workers' hearing.

Conventional audiometry, extended high-frequency audiometry, and DPOAEs in youth recreational firearm users.

To determine if conventional audiometry, EHFA, and pDPOAEs are useful as early indicators of cochlear damage from recreational firearm impulse noise exposure in youth firearm users. Quantitative cross-sectional descriptive pilot study. Descriptive statistics and MANOVA with post hoc Tukey Honestly Significant Difference test were used to compare pDPOAEs (1-10 kHz), conventional audiometry (0.25-8 kHz), and EHFA (10-16 kHz) in YFUs. 25 YFUs (n = 11 7-12 years; n = 14 13-17 years) with self-reported poor compliance with hearing protector device wear. Conventional audiometric thresholds at 2-, 3- and 4 kHz were significantly poorer than normal but did not distinguish between older and younger YFUs or between the GBE and the contralateral ear. EHFA thresholds at 14- and 16 kHz were significantly poorer than for other frequencies, and differentiate between older and younger youths, but do not distinguish the GBE from the contralateral ear. Finally, pDPOAE levels were significantly reduced at 8- and 10 kHz but did not show any differences for the younger versus older YFUs or for the GBE from the contralateral ear. Conclusion: Both EHFA and pDPOAEs provide early evidence of NIHL in YFUs, and may be useful for the early detection of NIHL in YFUs.

Cochrane corner: platinum-induced hearing loss after treatment for childhood cancer.

This Cochrane Corner features the review entitled "Platinum-induced hearing loss after treatment for childhood cancer" published in 2016. In their review, van As et al. identified 13 cohort studies including 2837 participants with a hearing test after treatment with a platinum-based therapy for different types of childhood cancers. All studies had problems related to quality of the evidence. The reported frequency of hearing loss varied between 1.7% and 90.1% for studies that included a definition of hearing loss; none of the studies provided data on tinnitus. Only two studies evaluated possible risk factors. One study found a higher risk of hearing loss in people treated with the combination of cisplatin plus carboplatin compared to treatment with cisplatin only and for exposure to aminoglycosides. The other found that age at treatment (lower risk in older children) and single maximum cisplatin dose (higher risk with an increasing dose) were significant predictors for hearing loss, while gender was not. This systematic review shows that children treated with platinum analogues are at risk of developing hearing loss, but the exact prevalence and risk factors remain unclear.

The reduction of gunshot noise and auditory risk through the use of firearm suppressors and low-velocity ammunition.

OBJECTIVE: This research assessed the reduction of peak levels, equivalent energy and sound power of firearm suppressors. DESIGN: The first study evaluated the effect of three suppressors at four microphone positions around four firearms. The second study assessed the suppressor-related reduction of sound power with a 3 m hemispherical microphone array for two firearms. RESULTS: The suppressors reduced exposures at the ear between 17 and 24 dB peak sound pressure level and reduced the 8 h equivalent A-weighted energy between 9 and 21 dB depending upon the firearm and ammunition. Noise reductions observed for the instructor's position about a metre behind the shooter were between 20 and 28 dB peak sound pressure level and between 11 and 26 dB LAeq,8h. Firearm suppressors reduced the measured sound power levels between 2 and 23 dB. Sound power reductions were greater for the low-velocity ammunition than for the same firearms fired with high-velocity ammunition due to the effect of N-waves produced by a supersonic bullet. CONCLUSIONS: Firearm suppressors may reduce noise exposure, and the cumulative exposures of suppressed firearms can still present a significant hearing risk. Therefore, firearm users should always wear hearing protection whenever target shooting or hunting.

Using tablet-based technology to deliver time-efficient ototoxicity monitoring.

OBJECTIVE: The goal of this article is to highlight mobile technology that is not yet standard of care but could be considered for use in an ototoxicity monitoring programme (OMP) as an adjunct to traditional audiometric testing. Current guidelines for ototoxicity monitoring include extensive test protocols performed by an audiologist in an audiometric booth. This approach is comprehensive, but it may be taxing for patients suffering from life-threatening illnesses and cost prohibitive if it requires serial clinical appointments. With the use of mobile technology, testing outside of the confines of the audiometric booth may be possible, which could create more efficient and less burdensome OMPs. DESIGN: A non-systematic review of new OMP technology was performed. Experts were canvassed regarding the impact of new technology on OMPs. STUDY SAMPLE: OMP devices and technologies that are commercially available and discussed in the literature. RESULTS: The benefits and limitations of portable, tablet-based technology that can be deployed for efficient ototoxicity monitoring are discussed. CONCLUSIONS: New mobile technology has the potential to influence the development and implementation of OMPs and lower barriers to patient access by providing time efficient, portable and self-administered testing options for use in the clinic and in the patient's home.

Chemoradiation-induced hearing loss remains a major concern for head and neck cancer patients.

OBJECTIVE: Review of the literature regarding hearing loss in patients with head and neck cancer treated with chemoradiation. DESIGN: Studies in the literature are reviewed that pertain to hearing loss sustained in head and neck cancer patients receiving cisplatin-based chemoradiation. Personal observations noted while treating these patients are also detailed. STUDY SAMPLE: PubMed was searched for pertinent articles regarding hearing loss in head and neck cancer patients receiving cisplatin chemotherapy and/or radiation. RESULTS: Studies on the incidence and severity of hearing loss in head and neck cancer patients are limited, but those studies suggest that the risk of hearing loss is greater with higher-dose regimens. CONCLUSIONS: Newer cisplatin chemotherapy regimens using lower, weekly doses may be associated with a lower incidence and severity of hearing loss; however, large prospective studies are needed. Such information will be paramount to effective pre-treatment counselling of head and neck cancer patients.

Acoustic reflexes are common but not pervasive: evidence using a diagnostic middle ear analyser.

OBJECTIVE: The objective of this study is to determine whether acoustic reflexes are pervasive (i.e. known with 95% confidence to be observed in at least 95% of people) by examining the frequency of occurrence using a friction-fit diagnostic middle ear analyser. DESIGN: Adult participants with very good hearing sensitivity underwent audiometric and middle ear testing. Acoustic reflexes were tested ipsilaterally and contralaterally in both ears across a range of elicitor frequencies. Reflex elicitors were 700 ms tones presented at maximum level of 100 dB HL. Two automated methods were used to detect the presence of an acoustic reflex. STUDY SAMPLE: A group of 285 adult volunteers with normal hearing. RESULTS: There were no conditions in which the proportion of participants exhibiting acoustic reflexes was high enough to be deemed pervasive. Ipsilateral reflexes were more likely to be observed than contralateral reflexes and reflexes were more common at 0.5 and 1 kHz elicitor frequencies as compared with 2 and 4 kHz elicitor frequencies. CONCLUSIONS: Acoustic reflexes are common among individuals with good hearing. However, acoustic reflexes are not pervasive and should not be included in damage risk criteria and health hazard assessments for impulsive noise.

Costs and effectiveness of hearing conservation programs at 14 US metal manufacturing facilities.

OBJECTIVE: This study characterised overall and specific costs associated with hearing conservation programmes (HCPs) at US metal manufacturing sites, and examined the association between these costs and several noise-induced hearing loss (NIHL) outcomes. DESIGN: We interviewed personnel and reviewed records at participating facilities. We also measured noise for comparison to the ten-year average of measurements made by each facility. NIHL outcomes assessed included rates of standard threshold shifts (STS) and high-frequency hearing loss, as well as prevalence of hearing impairment, for each participating facility. We used linear regression to identify per-person HCP costs that best predicted the NIHL outcomes. STUDY SAMPLE: We evaluated 14 US metal manufacturing facilities operated by a single company. RESULTS: Annual HCP costs ranged from roughly $67,000 to $397,000 (average $308 ± 80 per worker). Our full-shift noise measurements (mean 83.1 dBA) showed good agreement with the facilities' measurements (mean 82.6 dBA). Hearing impairment prevalence was about 15% overall. Higher expenditures for training and hearing protector fit-testing were significantly associated with reduced STS prevalence. Higher training expenditures were also related to lower hearing impairment prevalence and high-frequency hearing loss rates. CONCLUSIONS: HCP costs were substantial and variable. Increased workplace spending on training and fit-testing may help minimise NIHL.

Caring for musicians' ears: insights from audiologists and manufacturers reveal need for evidence-based guidelines.

OBJECTIVE: This study investigated clinical care delivered to musicians in Australia by audiologists and manufacturers of musicians' hearing protectors (MHP). DESIGN: Audiologists with experience treating musicians were invited to complete a survey on their service delivery. A second survey was administered to manufacturers of MHPs. STUDY SAMPLE: Four manufacturers of MHP and 31 audiologists completed the surveys. Post hoc analyses were performed comparing the responses of audiologists with more versus less clinical experience; and those with and without musical training. RESULTS: There was considerable variation in the audiological care provided to musicians. Only one-third of audiologists performed pure-tone audiometry prior to MHP fitting, and there was little consistency across the sample in relation to impression taking, preferred attenuation or selection of canal length. There was also significant variation in the manufacturers' approach to MHP, each of whom provided different recommendations regarding preferred impression techniques and material viscosity. CONCLUSIONS: The results of this study reveal lack of consistency across the hearing healthcare sector with respect to care of musicians' hearing, with potential to impact upon the satisfaction with, and usage of, MHP. There is need for evidence-based, best practice guidelines and training to support clinical audiologists in providing optimal care.

Examining the noisy life of the college musician: weeklong noise dosimetry of music and non-music activities.

OBJECTIVE: To examine the contribution of all daily activities, including non-music activities, to the overall noise exposure of college student musicians, and to compare their "noise lives" with those of non-musician college students. DESIGN: Continuous week-long dosimetry measurements were collected on student musicians and non-musicians. During the measurement period, participants recorded their daily activities in journals. STUDY SAMPLE: 22 musicians and 40 non-musicians, all students (aged 18-24 years) at the University of Connecticut. RESULTS: On every day of the week, musicians experienced significantly higher average exposure levels than did non-musicians. Nearly half (47%) of the musicians' days exceeded a daily dose of 100%, compared with 10% of the non-musicians' days. When the exposure due to music activities was removed, musicians still led noisier lives, largely due to participation in noisier social activities. For some musicians, non-music activities contributed a larger share of their total weekly noise exposure than did their music activities. CONCLUSIONS: Compared with their non-musician peers, college student musicians are at higher risk for noise-induced hearing loss (NIHL). On a weekly basis, non-music activities may pose a greater risk to some musicians than music activities. Thus, hearing health education for musicians should include information about the contribution of lifestyle factors outside of music to NIHL risk.

Applying U.S. national guidelines for ototoxicity monitoring in adult patients: perspectives on patient populations, service gaps, barriers and solutions.

OBJECTIVES: To promote establishment of effective ototoxicity monitoring programs (OMPs), this report reviews the U.S. national audiology guidelines in relation to "real world" OMP application. Background is provided on the mechanisms, risks and clinical presentation of hearing loss associated with major classes of ototoxic medications. DESIGN: This is a non-systematic review using PubMed, national and international agency websites, personal communications between ototoxicity experts, and results of unpublished research. Examples are provided of OMPs in various healthcare settings within the U.S. civilian sector, Department of Defense (DoD), and Department of Veterans Affairs (VA). STUDY SAMPLE: The five OMPs compared in this report represent a convenience sample of the programs with which the authors are affiliated. Their opinions were elicited via two semi-structured teleconferences on barriers and facilitators of OMP, followed by a self-administered questionnaire on OMP characteristics and practices, with responses synthesized herein. Preliminary results are provided from an ongoing VA clinical trial at one of these OMP sites. Participants were 40 VA patients who received cisplatin chemotherapy in 2014-2017. The study arms contrast access to care for OMP delivered on the treatment unit versus usual care as provided in the audiology clinic. RESULTS: Protocols of the OMPs examined varied, reflecting their diverse settings. Service delivery concerns included baseline tests missed or completed after the initial treatment, and monitoring tests done infrequently or only after cessation of treatment. Perceived barriers involved logistics related to accessing and testing patients, such as a lack of processes to help patients enter programs, patients' time and scheduling constraints, and inconvenient audiology clinic locations. Use of abbreviated or screening methods facilitated monitoring. CONCLUSIONS: The most effective OMPs integrated audiological management into care pathways of the clinical specialties that prescribe ototoxic medications. More OMP guidance is needed to inform evaluation schedules, outcome reporting, and determination of actionable ototoxic changes. Guidance is also lacking on the use of hearing conservation approaches suitable for the mass testing needed to support large-scale OMP efforts. Guideline adherence might improve with formal endorsement from organizations governing the medical specialty stakeholders in OMP such as oncologists, pulmonologists, infectious disease specialists, ototolaryngologists and pharmacists.

Knowledge and attitude of mothers regarding infant hearing loss in Changsha, Hunan province, China.

OBJECTIVE: The objective of this study was to explore the knowledge and attitude among mothers of newborns regarding infant hearing loss (HL) in Changsha, Hunan province, China. DESIGN: A questionnaire including 18 items was given to mothers. STUDY SAMPLE: A total of 115 mothers participated in the study. RESULTS: Seven risk factors for hearing loss were identified correctly by above 60% of respondents and the top three were prolonged noise (88.7%), high fever (82.6%) and ear discharge (82.6%). Poor knowledge was demonstrated on risk factors jaundice (20.0%), measles (22.6%), convulsion (33.0%) and traditional Chinese medicine (39.1%). Maternal knowledge scores in identification and intervention (2.68 ± 0.31) was slightly higher than the score in risk factors (2.47 ± 0.34). Ninety-nine per cent of the mothers expressed the willingness to test baby's hearing soon after birth and concern about hearing. CONCLUSIONS: Mothers were concerned about baby's hearing and the attitude was positive. However, the correct recognition rate towards some risk factors for HL was low. Action needs to be taken to raise awareness about ear and hearing care, prevent HL caused by preventable causes and prompt early identification, early diagnosis and intervention of HL.

Statistical tool to detect small hearing threshold shifts.

OBJECTIVE: The aim of this study is to present a new tool that can be used in the prevention of noise-induced hearing loss. Even in most countries where noise levels are well regulated, many workers are still exposed to high levels of noise and suffer from permanent threshold shifts. It is necessary to develop a new strategy to prevent such damage. METHOD: A statistical process control (SPC) scheme is presented that is able to detect both large and small hearing threshold shifts. Monte Carlo simulations were used to assess the performance of this hearing monitoring scheme. Different hearing threshold shifts were simulated to evaluate the performance of a variety of hearing development scenarios. RESULTS: It is possible to detect hearing threshold shifts smaller than the standard deviation of the hearing tests performed. This means that permanent hearing threshold shifts smaller than 5 dB can be detected and acted on. Outliers can also be automatically detected and treated, increasing the robustness of the monitoring scheme. CONCLUSION: The proposed statistical framework can be used as an early warning indicator of noise-induced hearing loss with the aim of improving workers' safety. Individual counteractions can be implemented, reducing the risk of further damage.