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Figure 1.  Study Flowchart
Study Flowchart

PTA indicates pure-tone audiometry.

Figure 2.  Hearing Thresholds as a Function of Cumulative Noise Exposure (CNE) at Different Frequencies Among Workers Aged 40 Years or Younger
Hearing Thresholds as a Function of Cumulative Noise Exposure (CNE) at Different Frequencies Among Workers Aged 40 Years or Younger

The black solid line is a fitting line with an intercept of 0. dBA indicates A-weighted dB; HL, hearing level.

Figure 3.  Longitudinal Progression in Hearing Thresholds of Workers Followed up From 2015 to 2019
Longitudinal Progression in Hearing Thresholds of Workers Followed up From 2015 to 2019

Data are shown as means, with whiskers indicating SDs. HL indicates hearing level.

Figure 4.  Auditory Processing Test Scores in Noise Exposed Group 1 (NG 1), Noise Exposed Group 2 (NG 2), and the Control Group
Auditory Processing Test Scores in Noise Exposed Group 1 (NG 1), Noise Exposed Group 2 (NG 2), and the Control Group

CST indicates competing sentences test; DLT, dichotic listening test; GDT, gap detection threshold; NS, not significant; SINT, speech-in-noise test; SIQT, speech-in-quiet test.

Table.  Demographic Characteristics of the Sample
Demographic Characteristics of the Sample
1.
Gourévitch  B, Edeline  JM, Occelli  F, Eggermont  JJ.  Is the din really harmless? long-term effects of non-traumatic noise on the adult auditory system.   Nat Rev Neurosci. 2014;15(7):483-491. doi:10.1038/nrn3744PubMedGoogle ScholarCrossref
2.
Zhou  X, Merzenich  MM.  Environmental noise exposure degrades normal listening processes.   Nat Commun. 2012;3:843. doi:10.1038/ncomms1849PubMedGoogle ScholarCrossref
3.
Fitzgibbons  PJ, Gordon-Salant  S.  Temporal gap resolution in listeners with high-frequency sensorineural hearing loss.   J Acoust Soc Am. 1987;81(1):133-137. doi:10.1121/1.395022PubMedGoogle ScholarCrossref
4.
Moore  DR, Edmondson-Jones  M, Dawes  P,  et al.  Relation between speech-in-noise threshold, hearing loss and cognition from 40-69 years of age.   PLoS One. 2014;9(9):e107720. doi:10.1371/journal.pone.0107720PubMedGoogle Scholar
5.
Lin  FR, Albert  M.  Hearing loss and dementia—who is listening?   Aging Ment Health. 2014;18(6):671-673. doi:10.1080/13607863.2014.915924PubMedGoogle ScholarCrossref
6.
Sheppard  A, Ralli  M, Gilardi  A, Salvi  R.  Occupational noise: auditory and non-auditory consequences.   Int J Environ Res Public Health. 2020;17(23):E8963. doi:10.3390/ijerph17238963PubMedGoogle Scholar
7.
Rabinowitz  PM, Galusha  D, Slade  MD, Dixon-Ernst  C, Sircar  KD, Dobie  RA.  Audiogram notches in noise-exposed workers.   Ear Hear. 2006;27(6):742-750. doi:10.1097/01.aud.0000240544.79254.bcPubMedGoogle ScholarCrossref
8.
Nondahl  DM, Shi  X, Cruickshanks  KJ,  et al.  Notched audiograms and noise exposure history in older adults.   Ear Hear. 2009;30(6):696-703. doi:10.1097/AUD.0b013e3181b1d418PubMedGoogle ScholarCrossref
9.
Wilson  M, Reynolds  G, Kauppinen  RA, Arvanitis  TN, Peet  AC.  A constrained least-squares approach to the automated quantitation of in vivo 1H magnetic resonance spectroscopy data.   Magn Reson Med. 2011;65(1):1-12. doi:10.1002/mrm.22579PubMedGoogle ScholarCrossref
10.
Wilson  RH.  Some observations on the nature of the audiometric 4000 Hz notch: data from 3430 veterans.   J Am Acad Audiol. 2011;22(1):23-33. doi:10.3766/jaaa.22.1.4PubMedGoogle Scholar
11.
Sayler  SK, Roberts  BJ, Manning  MA, Sun  K, Neitzel  RL.  Patterns and trends in OSHA occupational noise exposure measurements from 1979 to 2013.   Occup Environ Med. 2019;76(2):118-124. doi:10.1136/oemed-2018-105041PubMedGoogle ScholarCrossref
12.
Coles  RR, Lutman  ME, Buffin  JT.  Guidelines on the diagnosis of noise-induced hearing loss for medicolegal purposes.   Clin Otolaryngol Allied Sci. 2000;25(4):264-273. doi:10.1046/j.1365-2273.2000.00368.xPubMedGoogle ScholarCrossref
13.
Knight  KR, Kraemer  DF, Winter  C, Neuwelt  EA.  Early changes in auditory function as a result of platinum chemotherapy: use of extended high-frequency audiometry and evoked distortion product otoacoustic emissions.   J Clin Oncol. 2007;25(10):1190-1195. doi:10.1200/JCO.2006.07.9723PubMedGoogle ScholarCrossref
14.
Yu  KK, Choi  CH, An  YH,  et al.  Comparison of the effectiveness of monitoring cisplatin-induced ototoxicity with extended high-frequency pure-tone audiometry or distortion-product otoacoustic emission.   Korean J Audiol. 2014;18(2):58-68. doi:10.7874/kja.2014.18.2.58PubMedGoogle ScholarCrossref
15.
Antonioli  CA, Momensohn-Santos  TM, Benaglia  TA.  High-frequency audiometry hearing on monitoring of individuals exposed to occupational noise: a systematic review.   Int Arch Otorhinolaryngol. 2016;20(3):281-289.PubMedGoogle Scholar
16.
Mehrparvar  AH, Mirmohammadi  SJ, Ghoreyshi  A, Mollasadeghi  A, Loukzadeh  Z.  High-frequency audiometry: a means for early diagnosis of noise-induced hearing loss.   Noise Health. 2011;13(55):402-406. doi:10.4103/1463-1741.90295PubMedGoogle ScholarCrossref
17.
Laffoon  SM, Stewart  M, Zheng  Y, Meinke  DK.  Conventional audiometry, extended high-frequency audiometry, and DPOAEs in youth recreational firearm users.   Int J Audiol. 2019;58(sup1):S40-S48. doi:10.1080/14992027.2018.1536833PubMedGoogle ScholarCrossref
18.
Liberman  MC, Kujawa  SG.  Cochlear synaptopathy in acquired sensorineural hearing loss: manifestations and mechanisms.   Hear Res. 2017;349:138-147. doi:10.1016/j.heares.2017.01.003PubMedGoogle ScholarCrossref
19.
Kujawa  SG, Liberman  MC.  Adding insult to injury: cochlear nerve degeneration after “temporary” noise-induced hearing loss.   J Neurosci. 2009;29(45):14077-14085. doi:10.1523/JNEUROSCI.2845-09.2009PubMedGoogle ScholarCrossref
20.
Ralli  M, Greco  A, De Vincentiis  M,  et al.  Tone-in-noise detection deficits in elderly patients with clinically normal hearing.   Am J Otolaryngol. 2019;40(1):1-9. doi:10.1016/j.amjoto.2018.09.012PubMedGoogle ScholarCrossref
21.
Prendergast  G, Couth  S, Millman  RE,  et al.  Effects of age and noise exposure on proxy measures of cochlear synaptopathy.   Trends Hear. 2019;23:2331216519877301. doi:10.1177/2331216519877301PubMedGoogle Scholar
22.
Fitzgibbons  PJ, Wightman  FL.  Gap detection in normal and hearing-impaired listeners.   J Acoust Soc Am. 1982;72(3):761-765. doi:10.1121/1.388256PubMedGoogle ScholarCrossref
23.
Shi  L, Chang  Y, Li  X, Aiken  S, Liu  L, Wang  J.  Cochlear synaptopathy and noise-induced hidden hearing loss.   Neural Plast. 2016;2016:6143164. doi:10.1155/2016/6143164PubMedGoogle Scholar
24.
Saunders  GH, Frederick  MT, Arnold  M, Silverman  S, Chisolm  TH, Myers  P.  Auditory difficulties in blast-exposed veterans with clinically normal hearing.   J Rehabil Res Dev. 2015;52(3):343-360. doi:10.1682/JRRD.2014.11.0275PubMedGoogle ScholarCrossref
25.
Schaette  R, McAlpine  D.  Tinnitus with a normal audiogram: physiological evidence for hidden hearing loss and computational model.   J Neurosci. 2011;31(38):13452-13457. doi:10.1523/JNEUROSCI.2156-11.2011PubMedGoogle ScholarCrossref
26.
Lobarinas  E, Salvi  R, Ding  D.  Selective inner hair cell dysfunction in chinchillas impairs hearing-in-noise in the absence of outer hair cell loss.   J Assoc Res Otolaryngol. 2016;17(2):89-101. doi:10.1007/s10162-015-0550-8PubMedGoogle ScholarCrossref
27.
Prendergast  G, Guest  H, Munro  KJ,  et al.  Effects of noise exposure on young adults with normal audiograms I: electrophysiology.   Hear Res. 2017;344:68-81. doi:10.1016/j.heares.2016.10.028PubMedGoogle ScholarCrossref
28.
Kujawa  SG, Liberman  MC.  Acceleration of age-related hearing loss by early noise exposure: evidence of a misspent youth.   J Neurosci. 2006;26(7):2115-2123. doi:10.1523/JNEUROSCI.4985-05.2006PubMedGoogle ScholarCrossref
29.
Villavisanis  DF, Schrode  KM, Lauer  AM.  Sex bias in basic and preclinical age-related hearing loss research.   Biol Sex Differ. 2018;9(1):23. doi:10.1186/s13293-018-0185-7PubMedGoogle ScholarCrossref
30.
Agrawal  Y, Niparko  JK, Dobie  RA.  Estimating the effect of occupational noise exposure on hearing thresholds: the importance of adjusting for confounding variables.   Ear Hear. 2010;31(2):234-237. doi:10.1097/AUD.0b013e3181c6b9fdPubMedGoogle ScholarCrossref
31.
Kujala  T, Shtyrov  Y, Winkler  I,  et al.  Long-term exposure to noise impairs cortical sound processing and attention control.   Psychophysiology. 2004;41(6):875-881. doi:10.1111/j.1469-8986.2004.00244.xPubMedGoogle ScholarCrossref
32.
Tepe  V, Papesh  M, Russell  S, Lewis  MS, Pryor  N, Guillory  L.  Acquired central auditory processing disorder in service members and veterans.   J Speech Lang Hear Res. 2020;63(3):834-857. doi:10.1044/2019_JSLHR-19-00293PubMedGoogle ScholarCrossref
33.
National Health and Family Planning Commission of the People’s Republic of China. Measurement of physical agents in the workplace—part 8: noise. November 9, 2007. Accessed August 3, 2021. https://www.chinesestandard.net/PDF/BOOK.aspx/GBZT189.8-2007
34.
Wong  LL, Soli  SD, Liu  S, Han  N, Huang  MW.  Development of the Mandarin Hearing in Noise Test (MHINT).   Ear Hear. 2007;28(2)(suppl):70S-74S. doi:10.1097/AUD.0b013e31803154d0PubMedGoogle ScholarCrossref
35.
Feng  Y, Yin  S, Kiefte  M, Wang  J.  Temporal resolution in regions of normal hearing and speech perception in noise for adults with sloping high-frequency hearing loss.   Ear Hear. 2010;31(1):115-125. doi:10.1097/AUD.0b013e3181bb69bePubMedGoogle ScholarCrossref
36.
Li  K, Xia  L, Zheng  Z,  et al.  A preliminary study on time-compressed speech recognition in noise among teenage students who use personal listening devices.   Int J Audiol. 2019;58(3):125-131. doi:10.1080/14992027.2018.1536298PubMedGoogle ScholarCrossref
37.
Korres  GS, Balatsouras  DG, Tzagaroulakis  A, Kandiloros  D, Ferekidis  E.  Extended high-frequency audiometry in subjects exposed to occupational noise.   B-ENT. 2008;4(3):147-155.PubMedGoogle Scholar
38.
Škerková  M, Kovalová  M, Mrázková  E.  High-frequency audiometry for early detection of hearing loss: a narrative review.   Int J Environ Res Public Health. 2021;18(9):4702. doi:10.3390/ijerph18094702PubMedGoogle ScholarCrossref
39.
Bharadwaj  HM, Masud  S, Mehraei  G, Verhulst  S, Shinn-Cunningham  BG.  Individual differences reveal correlates of hidden hearing deficits.   J Neurosci. 2015;35(5):2161-2172. doi:10.1523/JNEUROSCI.3915-14.2015PubMedGoogle ScholarCrossref
40.
Xiong  H, Chen  L, Yang  H,  et al.  Hidden hearing loss in tinnitus patients with normal audiograms: implications for the origin of tinnitus.  Article in Chinese.  Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi. 2013;27(7):362-365.PubMedGoogle Scholar
41.
Spankovich  C, Gonzalez  VB, Su  D, Bishop  CE.  Self-reported hearing difficulty, tinnitus, and normal audiometric thresholds, the National Health and Nutrition Examination Survey 1999-2002.   Hear Res. 2018;358:30-36.PubMedGoogle ScholarCrossref
42.
Grose  JH, Buss  E, Hall  JW  III.  Loud music exposure and cochlear synaptopathy in young adults: isolated auditory brainstem response effects but no perceptual consequences.   Trends Hear. 2017;21:2331216517737417. doi:10.1177/2331216517737417PubMedGoogle Scholar
43.
Fulbright  ANC, Le Prell  CG, Griffiths  SK, Lobarinas  E.  Effects of recreational noise on threshold and suprathreshold measures of auditory function.   Semin Hear. 2017;38(4):298-318. doi:10.1055/s-0037-1606325PubMedGoogle Scholar
44.
Prendergast  G, Millman  RE, Guest  H,  et al.  Effects of noise exposure on young adults with normal audiograms II: behavioral measures.   Hear Res. 2017;356:74-86. doi:10.1016/j.heares.2017.10.007PubMedGoogle ScholarCrossref
45.
Yeend  I, Beach  EF, Sharma  M, Dillon  H.  The effects of noise exposure and musical training on suprathreshold auditory processing and speech perception in noise.   Hear Res. 2017;353:224-236. doi:10.1016/j.heares.2017.07.006PubMedGoogle ScholarCrossref
46.
Guest  H, Munro  KJ, Prendergast  G, Millman  RE, Plack  CJ.  Impaired speech perception in noise with a normal audiogram: no evidence for cochlear synaptopathy and no relation to lifetime noise exposure.   Hear Res. 2018;364:142-151. doi:10.1016/j.heares.2018.03.008PubMedGoogle ScholarCrossref
47.
Valderrama  JT, Beach  EF, Yeend  I, Sharma  M, Van Dun  B, Dillon  H.  Effects of lifetime noise exposure on the middle-age human auditory brainstem response, tinnitus and speech-in-noise intelligibility.   Hear Res. 2018;365:36-48. doi:10.1016/j.heares.2018.06.003PubMedGoogle ScholarCrossref
48.
Lobarinas  E, Salvi  R, Ding  D.  Gap detection deficits in chinchillas with selective carboplatin-induced inner hair cell loss.   J Assoc Res Otolaryngol. 2020;21(6):475-483. doi:10.1007/s10162-020-00744-5PubMedGoogle ScholarCrossref
49.
Salvi  R, Sun  W, Ding  D,  et al.  Inner hair cell loss disrupts hearing and cochlear function leading to sensory deprivation and enhanced central auditory gain.   Front Neurosci. 2017;10:621. doi:10.3389/fnins.2016.00621PubMedGoogle ScholarCrossref
50.
Starr  A, Michalewski  HJ, Zeng  FG,  et al.  Pathology and physiology of auditory neuropathy with a novel mutation in the MPZ gene (Tyr145->Ser).   Brain. 2003;126(Pt 7):1604-1619. doi:10.1093/brain/awg156PubMedGoogle Scholar
51.
Fernandez  KA, Jeffers  PW, Lall  K, Liberman  MC, Kujawa  SG.  Aging after noise exposure: acceleration of cochlear synaptopathy in “recovered” ears.   J Neurosci. 2015;35(19):7509-7520. doi:10.1523/JNEUROSCI.5138-14.2015PubMedGoogle ScholarCrossref
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    Original Investigation
    Environmental Health
    September 3, 2021

    Analysis of Early Biomarkers Associated With Noise-Induced Hearing Loss Among Shipyard Workers

    Author Affiliations
    • 1Department of Otolaryngology–Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, China
    • 2Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China
    • 3Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai, China
    • 4Department of Occupational Disease, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai, China
    • 5School of Communication Science and Disorders, Dalhousie University, Halifax, Nova Scotia, Canada
    • 6Center for Hearing and Deafness, University at Buffalo, Buffalo, New York
    JAMA Netw Open. 2021;4(9):e2124100. doi:10.1001/jamanetworkopen.2021.24100
    Key Points

    Question  Is the increase of hearing loss among shipyard workers more rapid at 12.5 kHz than at lower frequencies, and do any auditory processing deficits occur before there is significant hearing loss?

    Findings  In this cross-sectional study of 7890 shipyard workers, hearing loss at 12.5 kHz was more rapid than at lower frequencies. Greater cumulative noise exposure was associated with auditory processing deficits among those with near-normal hearing.

    Meaning  These findings suggest that a 12.5-kHz threshold and auditory processing disorders could serve as early indicators of noise-induced hearing impairment.

    Abstract

    Importance  It is important to determine what frequencies and auditory perceptual measures are the most sensitive early indicators of noise-induced hearing impairment.

    Objectives  To examine whether hearing loss among shipyard workers increases more rapidly at extended high frequencies than at clinical frequencies and whether subtle auditory processing deficits are present in those with extensive noise exposure but little or no hearing loss.

    Design, Setting, and Participants  This cross-sectional study collected audiometric data (0.25-16 kHz), survey questionnaires, and noise exposure levels from 7890 shipyard workers in a Shanghai shipyard from 2015 to 2019. Worsening hearing loss was evaluated in the group with hearing loss. Speech processing and temporal processing were evaluated in 610 participants with noise exposure and clinically normal hearing to identify early biomarkers of noise-induced hearing impairment. Data analysis was conducted from November to December 2020.

    Main Outcomes and Measures  Linear regression was performed to model the increase in hearing loss as function of cumulative noise exposure and compared with a group who were monitored longitudinally for 4 years. Auditory processing tests included speech-in-noise tests, competing sentence tests, dichotic listening tests, and gap detection threshold tests and were compared with a control group without history of noise exposure.

    Results  Of the 5539 participants (median [interquartile range (IQR)] age, 41.0 [34.0-47.0] years; 3861 [86.6%] men) included in the cross-sectional analysis, 4459 (80.5%) were hearing loss positive and 1080 (19.5%) were hearing loss negative. In younger participants (ie, ≤40 years), the maximum rate of increase in hearing loss was 0.40 (95% CI, 0.39-0.42) dB per A-weighted dB–year (dB/dBA-year) at 12.5 kHz, higher than the growth rates of 0.36 (95% CI, 0.35-0.36) dB/dBA-year at 4 kHz, 0.32 (95% CI, 0.31-0.33) dB/dBA-year at 10 kHz, 0.31 (95% CI, 0.30-0.31) dB/dBA-year at 6 kHz, 0.27 (95% CI, 0.26-0.27) dB/dBA-year at 3 kHz, and 0.27 (95% CI, 0.27-0.28) dB/dBA-year at 8 kHz. In the 4-year longitudinal analysis of hearing loss among 403 participants, the mean (SD) annual deterioration in hearing was 2.70 (2.98) dB/y at 12.5 kHz, almost twice as that observed at lower frequencies (eg, at 3kHz: 1.18 [2.15] dB/y). The auditory processing scores of participants with clinically normal hearing and a history of noise exposure were significantly lower than those of control participants (eg, median [IQR] score on speech-in-noise test, noise-exposed group 1 vs control group: 0.63 [0.55-0.66] vs 0.78 [0.76-0.80]; P < .001).

    Conclusions and Relevance  These findings suggest that the increase in hearing loss among shipyard workers was more rapid at 12.5 kHz than at other frequencies; workers with clinically normal hearing but high cumulative noise exposure are likely to exhibit deficits in speech and temporal processing.

    Introduction

    Prolonged and/or intense noise exposure contributes to numerous health problems, in particular noise-induced hearing loss (NIHL) that damages the cochlea.1,2 Noise-induced damage not only leads to hearing loss but can make it difficult to understand speech.3-5 Although many countries have established health and safety regulations,6 early detection of NIHL is of great importance for prevention.

    The most common biomarker used to identify NIHL is the shape of the audiogram.7-9 Historically, the so-called 4-kHz noise notch has been considered a hallmark of NIHL and is used to distinguish it from other types of sensorineural hearing losses associated with aging, ototoxic effects, and genetic factors.7,8,10-12 On the other hand, it has been suggested that notches can occur in the absence of a positive noise history.8 For the purpose of early detection and diagnosis of NIHL, extended high frequency (EHF) audiometry has gradually become a tool for routine clinical evaluation. Advocates point out the advantage of EHF in early identification of hearing loss due to ototoxic drugs and noise exposure.13-16 However, a systematic review failed to arrive at a robust conclusion regarding the advantage of EHF vs conventional audiometry.15 Most of the conclusions have been derived from a pool of participants with unclear durations and/or doses of noise exposure.16,17 In addition, many studies lacked longitudinal measurement of hearing. Therefore, the utility of EHF audiometry to test for early onset NIHL remains an open question.

    Traditionally, NIHL was defined by the permanent threshold shifts (PTS), while noise exposures that do not cause PTS were considered relatively safe. However, this idea has been challenged by data from animals in which significant noise-induced damage to the synapses between inner hair cells and spiral ganglion neurons occurred without PTS.18,19 This subclinical hearing damage, called hidden hearing loss, is not easily detected by routine hearing tests focused on thresholds, but it could contribute to temporal processing deficits or difficulty detecting or interpreting sounds in background noise.20-22 Some of these functional deficits are believed to be due to noise-induced synaptic damage.18,23 Several studies have tried to verify hidden hearing loss in human participants with mixed results.24-27 One problem with many studies is the lack of documented history of noise exposure, heterogeneity of participants, and a limited sample size from which to draw firm conclusions.28-32 With these limitations in mind, this study aimed to assess the growth of hearing loss in the clinical and EHF ranges and to identify auditory processing disorders (APDs) among workers with noise exposure to identify early biomarkers of noise-induced hearing impairment.

    Methods
    Study Design and Subjects

    Cross-sectional physical examination data were obtained from 7890 sanding, welding, metal, and cutting workers between June 2015 and June 2019. A questionnaire was filled out by each participant with demographic features; noise exposure history; type of work; smoking and alcohol drinking habits; history of major diseases, including genetic and drug-related hearing loss; and the use of hearing protection devices. This study was approved by the institutional ethics review board of the Shanghai Sixth People’s Hospital, affiliated with Shanghai Jiao Tong University, and was registered in the Chinese Clinical Trial Registry (ChiCTR-RPC-17012580). Potential consequences and benefits were explained, and written informed consent was obtained from each participant before this study. This study adheres to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline.

    Figure 1 outlines the procedures and criteria for participant inclusion and exclusion. A total of 5539 individuals were included in the cross-sectional analysis. Among them, 4459 participants had varying degrees of hearing loss (ie, pure-tone audiometry [PTA] >25 dB hearing level at any frequency from 0.25 to 8 kHz) and were classified as hearing loss positive. The remaining 1080 participants with clinical normal hearing (ie, PTA ≤25 dB from 0.25 to 8 kHz) were classified as hearing loss negative. More extensive auditory processing tests were carried out on a subgroup of 610 participants from the hearing loss–negative group according to the following criteria: younger than 40 years, right handed, and native Mandarin speaker. Among them, 110 participants had hearing level thresholds of 25 dB in both the clinical audiometric range (ie, 0.25-8 kHz) and the EHF range (10, 12.5, and 16 kHz); this group was considered noise-exposed group 1 (NG 1). The remaining 500 participants with PTA of 25 dB or less from 0.25 to 8 kHz but PTA of greater than 25 dB at EHFs were considered noise-exposed group 2 (NG 2). Another 110 participants with normal hearing and without a history of occupational noise exposure served as the control group; these individuals were matched with those in the NG 1 group in terms of age, sex, and years of education. Furthermore, the longitudinal analysis was restricted to 403 participants younger than 40 years old at the time of the first test who were followed up for 4 years (from 2015 to 2019) to calculate a hearing threshold difference statistic at each frequency.

    Noise Exposure Estimation

    Industrial noise was measured with an ASV5910-R digital recorder (Aihua Instruments) across the work areas of different jobs according to the national standard of China.33 Sound levels were measured using A-weighted dB (dBA). The long-term equivalent (leq) noise level was adopted as the primary exposure metric and measured 3 times at each spot. The mean value of the leq in each spot was transformed into an 8-hour continuous equivalent sound pressure level (leq-8h). Cumulative noise exposure (CNE, measured in dBA-years) was calculated using the leq-8h during the years of on-duty time, as follows: CNE = leq-8h + 10 × log(T), where the T is the career length in years.

    Audiological Evaluation

    Audiologic evaluations were performed on 7890 workers on site by qualified medical assistants in soundproof chambers. The tests were performed at least 12 hours after the participant’s last shift in the noise-exposed job. Otoscopic inspection and tympanometry were performed on each participant to establish the normal function of their external and middle ears. Tympanograms were measured using a TympStar tympanometer (Grason-Stadler). The passing criterion was a type A tympanogram (peak between −100 and 100 daPa). PTA was measured separately for each ear using a Type 1066 manual audiometer (Natus Hearing & Balance) with Sennheiser HDA-300 headphones for the clinical and EHF audiometric ranges. All thresholds were calculated in dB hearing level, and audiometers were calibrated annually according to the ISO 389-5-2006 standard. If a participant did not respond to at the maximum output of the audiometer at the EHFs (90, 80, and 60 dB hearing level for 10, 12.5, and 16 kHz), the data were removed to eliminate saturation effects.

    Auditory Processing Tests

    A battery of 5 auditory processing tests was performed in 2 soundproof rooms using an audiometer equipped with TDH-39 headphones; stimuli were presented at 40 dB sensation level. The speech-in-quiet test (SIQT), speech-in-noise test (SINT), and competing sentences test (CST) were assessed using the Mandarin version of the hearing-in-noise test that was developed with MATLAB version R2012a software.34 The dichotic listening test (DLT) was obtained from both the left ear and right ear. The gap detection threshold (GDT) was measured using a 3-interval forced-choice procedure designed with MATLAB software. The procedures used for these measurements have been described in previous studies.35,36 Speech recognition and DLT were scored as the percentage of correct responses. The GDT threshold (in milliseconds) was calculated from the mean value of the last 8 reversals.

    Statistical Analysis

    The baseline characteristics of participants were summarized as number and percentage for categorical variables and mean and SD for most continuous variables. Median and interquartile range (IQR) were used for skewed continuous variables. Differences in demographic characteristics and results of auditory processing measurements were analyzed by the nonparametric Kruskal-Wallis test and post hoc pairwise comparison with Bonferroni correction if the data were not normally distributed. Categorical data were compared using Pearson χ2 test. A linear regression line with a forced intercept of 0 was fit to the data to determine the rate of hearing loss increase (slope) from 3 to 12.5 kHz, which was compared using the Z test in a younger group (ie, ≤40 years) and older group (ie, >40 years). Repeated measures analysis of variance with 2 factors (year and frequency) were used to compare the difference between hearing thresholds from 2015 to 2019. A 2-tailed P < .05 was considered statistically significant. Data analyses were performed using R version 4.02 (R Project for Statistical Computing) and Prism version 8.4 (GraphPad Software).

    Results
    Characteristics of Participants

    The Table presents an overview of the demographic and hearing characteristics of the participants. Of the 5539 participants, 4459 (80.5%) had mild or greater hearing loss, the median (IQR) age was 41.0 (34.0-47.0) years, and 3861 (86.6%) were men. The median (IQR) career length was 7.5 (4.2-10.7) years, and the median (IQR) CNE was 92.9 (89.1-97.7) dBA-years. There were 1705 individuals (38.2%) who currently smoked, and 1685 (37.8%) who currently drank. In the hearing loss–negative group, the participants in the 3 groups (ie, NG 1, NG 2, and the control group) were fairly well matched except for PTAs. The median (IQR) PTAs at 0.25 to 2 kHz in NG 1 (9.7 [6.7-11.9] dB) and NG 2 (12.5 [9.4-15.0] dB) groups were significantly different from those in the control group (10.6 [8.8-12.5] dB; NG 1 vs control group: H = −2.247; P = .02; NG 2 vs control group: H = −4.675; P < .001), while there was no statistical difference between NG 1 and NG 2. The median (IQR) PTAs at 3 to 6 kHz and 10 to 16 kHz did not differ between the NG 1 group (3-6 kHz: 8.3 [6.7-11.7] dB; 10-16 kHz: 10.4 [6.7-13.3] dB) and the control group CG (3-6 kHz: 10.0 [7.5-12.5] dB; H = −0.524; P = .60; 10-16 kHz: 11.3 [8.3-16.7] dB; H = −0.130; P = .90), while there was a significant difference between the NG 2 group (3-6 kHz: 11.7 [8.3-15.0] dB; 10-16 kHz: 25.8 [19.2-33.3] dB) and the control group (3-6 kHz: H = −5.192; P < .001; 10-16 kHz: H = −15.964; P < .001). The mean (SD) age in the 2015 of the 403 workers in the longitudinal study was 31.7 (3.2) years, and the mean (SD) career length was 5.7 (1.7) years.

    Frequency-Dependent Increase in NIHL With CNE

    To determine the association of NIHL with an individual’s CNE, which combines exposure intensity and duration, scatterplots were constructed at frequencies from 3 to 12.5 kHz showing the hearing threshold as a function of CNE for each participant. In the younger group (ie, ≤40 years), the largest slopes were 0.40 (95% CI, 0.39-0.42) dB/dBA-year at 12.5 kHz, 0.36 (95% CI, 0.35-0.36) dB/dBA-year at 4 kHz, 0.32 (95% CI, 0.31-0.33) dB/dBA-year at 10 kHz, and 0.31 (95% CI, 0.30-0.31) dB/dBA-year at 6 kHz (Figure 2). The slopes at 3 and 8 kHz were both 0.27 (95% CI for 3 kHz, 0.26-0.27; 95% CI for 8 kHz, 0.27-0.28) dB/dBA-year. The growth rate of 12.5 kHz was significantly different from the other frequencies in the younger group and the older group (12.5 kHz vs 3 kHz: z = 33.78; P < .001; 12.5 kHz vs 4 kHz: z = 20.39; P < .001; 12.5 kHz vs 6 kHz: z = 30.87; P < .001; 12.5 kHz vs 8 kHz: z = 32.96; P < .001; 12.5 kHz vs 10 kHz: z = 20.90; P < .001). The same frequency-dependent trend was present in the older group (>40 years) (eFigure 1 in the Supplement). Scatterplots were also constructed showing the hearing threshold as a function of career length and leq-8h for each participant. The same trends were found, with the maximum slope at 12.5 kHz (eFigures 2-5 in the Supplement).

    Longitudinal Progression of Hearing Loss in Younger Participants

    Longitudinal progression of hearing loss was plotted as a function of frequency (Figure 3). During the 4-year study period, hearing loss increased by a mean (SD) of 4.7 (8.6) dB at 3 kHz, 5.0 (8.0) dB at 4 kHz, 3.5 (8.6) dB at 6 kHz and 5.5 (9.8) dB at 8 kHz, 8.3 (12.4) dB at 10 kHz, and 10.8 (11.9) dB at 12.5 kHz. A 2-way repeated analysis of variance showed that hearing thresholds in 2019 were significantly worse than in 2015 at 3, 4, 6, 8, 10, and 12.5 kHz; the mean (SD) annual deterioration in hearing was 2.70 (2.98) dB/y at 12.5 kHz, almost twice as great as at lower frequencies (mean [SD] annual deterioration at 3 kHz: 1.18 [2.15] dB/y; 4 kHz: 1.25 [2.00] dB/y; 6 kHz: 0.88 [2.15] dB/y; 8 kHz: 1.38 [2.45] dB/y; 10 kHz: 2.08 [3.10]).

    APDs Among Workers With Noise Exposure

    The NG 1, NG 2, and control groups had similar scores on the SIQT, with no overall or between-group differences (Figure 4A). However, when the 3 groups were evaluated on the SINT (Figure 4B), the median (IQR) scores in the control group were 0.78 (0.76-0.80), whereas those in the NG 1 group were 0.63 (0.55-0.66) and those in the NG 2 group was 0.65 (0.55-0.67). The median (IQR) scores in the NG 1 group and NG 2 group were significantly less than those in the CG group (NG 1 vs control: H = 11.71; P < .001; NG 2 vs control: H = 14.29; P < .001), but there was no significant difference between the NG 1 and NG 2 groups. The median (IQR) CST score (Figure 4C) in the CG group was 0.71 (0.66-0.74), while median (IQR) scores in the NG 1 and NG 2 groups were 0.51 (0.45-0.56) and 0.53 (0.45-0.56), respectively. CST scores in the NG 1 and NG-II group were significantly less than those in the control group (NG 1 vs control: H = 11.458; P < .001; NG 2 vs control: H = 14.142; P < .001). There was no significant difference between the NG 1 and NG 2 groups. The median (IQR) score on the DL left ear was 0.75 (0.65-0.89) in the control group vs 0.60 (0.50-0.75) for the NG 1 group and 0.60 (0.50-0.80) for the NG 2 group (Figure 4D). The DL left scores for the NG 1 and NG 2 groups were significantly less than those in the control group (NG 1 vs control: H = 6.417; P < .001; NG 2 vs control: H = 7.754; P < .001), but there was no significant difference between the NG 1 and NG 2 groups. In the right ear (Figure 4E), the median (IQR) DL score was 0.90 (0.80-0.95) in the control group, whereas the median (IQR) values were 0.70 (0.65-0.85) and 0.70 (0.65-0.85) in the NG 1 and NG 2 groups, respectively. The DL right ear scores in the NG 1 group and NG 2 group were significantly less than those in the control group (NG 1 vs control: H = 9.973; P < .001; NG 2 vs control: (H = 7.750; P < .001). There was no significant difference between the NG 1 and NG 2 groups. The median (IQR) GDT values in the control group were 2.75 (2.25-3.25) ms compared with 3.08 (2.67-3.67) ms in the NG 1 group and 3.17 (2.75-3.68) ms in the NG 2 group (Figure 4F). The GDT scores were significantly longer in the NG 1 and NG 2 groups compared with those in the control group (NG 1 vs control: H = 4.891; P < .001; NG 2 vs control: H = 7.584; P < .001), but there was no significant difference between the NG 1 and NG 2 groups.

    Discussion

    Among shipyard workers, we found that hearing thresholds were greater and increased more rapidly at EHFs compared with conventional audiometric frequencies. These trends were observed in both the cross-sectional and longitudinal analyses. Importantly, we found that workers with noise exposure in the NG 1 group (who had normal hearing at both clinical and EHFs) as well as workers in NG 2 (who had clinically normal hearing but elevated thresholds at EHFs) performed worse than the control group on the SINT, DLT, CST and GDT.

    Hearing loss has long relied on hearing tests that evaluate sensitivity in speech frequencies. While the equipment for conducting clinical audiometric tests is widely available, that for assessing hearing at the EHFs is more expensive and not widely available. The use of EHF audiometry as an early indicator of NIHL is still controversial, but our results, as well as previous studies,37,38 suggest that EHF audiometry (from 9-20 kHz) could identify the first signs of NIHL, especially at 12.5 to 18 kHz. We conducted a large-scale study on shipyard workers in China aged 20 to 60 years, on the assumption that people in this age range would be old enough for noise exposure effects to be measurable but young enough that aging effects would be minimized. The univariate linear regression showed that the maximum increase of hearing loss as a function of career length, type of work setting, and CNE occurred at 12.5 kHz, not only in young workers but even in those aged of 40 years and older in the group with hearing loss.

    In the longitudinal analysis (Figure 3), workers entering our longitudinal study in 2015 had the greatest hearing loss at 16 kHz; however, there was relatively little growth in hearing loss during the following 4 years, largely due to the fact that the maximum output of our transducer was 60 dB hearing level at 16 kHz so that thresholds saturated. The increase in hearing loss during the 4-year observation periods was 10.8 dB at 12.5 kHz, more than twice as that at 4 kHz (5.0 dB). These results suggest that the 12.5-kHz notch could be a more useful early indicator of NIHL than lower frequency notches.

    Considerable effort has been made to identify APDs in humans with a history of noise exposure. While some studies have identified APD (eg, speech in noise, temporal processing) in individuals with a history of noise exposure,39-41 many others have reported little or no correlation between the amount of noise exposure and APD.21,42-47 In our study, the suprathreshold deterioration in hearing function was seen in challenging speech processing tasks such as the SINT, CST, and DLT as well as the GDT. This result was observed even in the NG 1 group, in which the PTAs in both the conventional frequency range and EHFs showed no difference from participants in the control group. One possible source of these APDs is subclinical damage that disrupts the transmission of information from the inner hair cells to the afferent auditory nerve fibers or damage to the spiral ganglion neurons, as suggested by previous human and animal studies.26,48-50 However, in the absence of histopathological data, this interpretation remains speculative.

    Limitations

    This study has limitations. Some of the changes observed could be the result of aging, noise alone, or the interaction between early NIHL and aging.51 Further work is needed to better control for the effects of aging, but finding participants with minimal exposure to noise is becoming increasingly difficult in a world filled with numerous sound-generating devices. The definition of normal hearing in most studies is a threshold of 25 dB hearing level or less. While this may be a practical definition in a clinical setting, only those with thresholds of 0 dB (±10 dB) presumably have normal hearing. Also, there may be some bias in using self-reported data to calculate important variables.

    Conclusions

    Our findings suggest that growth of hearing loss among shipyard workers was more rapid at 12.5 kHz than at 4 kHz, suggesting that 12.5 kHz could be a sensitive biomarker of early NIHL. Workers with high CNE values, even those with normal hearing at both clinical frequencies and EHFs, were more likely to exhibit APD on SINT, DLT, CST and GDT, especially when CNE values exceeded 80 dBA-year. This was observed even among workers with normal hearing in both the clinical and EHF ranges.

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    Article Information

    Accepted for Publication: June 24, 2021.

    Published: September 3, 2021. doi:10.1001/jamanetworkopen.2021.24100

    Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2021 Jiang Z et al. JAMA Network Open.

    Corresponding Author: Hui Wang, PhD, Department of Otolaryngology–Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, 600 Yishan Rd, Shanghai 200233, China (wangh2005@alumni.sjtu.edu.cn).

    Author Contributions: Drs H. Wang and Yin had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

    Concept and design: Jiping Wang, Shi, Jian Wang, H. Wang, Yin.

    Acquisition, analysis, or interpretation of data: Jiang, Jiping Wang, Feng, Sun, Zhang, Shi, Jian Wang, Salvi, H. Wang.

    Drafting of the manuscript: Jiang, Jiping Wang, Zhang, Shi, Jian Wang, Salvi, H. Wang.

    Critical revision of the manuscript for important intellectual content: Feng, Sun, Shi, Jian Wang, H. Wang, Yin.

    Statistical analysis: Jiang, Feng, Shi, Jian Wang, Salvi, H. Wang.

    Obtained funding: Yin.

    Administrative, technical, or material support: Jiping Wang, Sun, Zhang, Salvi, H. Wang.

    Supervision: Feng, Shi, H. Wang, Yin.

    Conflict of Interest Disclosures: Dr Salvi reported receiving grants from the National Institutes of Health and serving as a consultant for Auris Pharmaceutical, CilCare, and law firms outside the submitted work. No other disclosures were reported.

    Funding/Support: This study was supported by grant 81720108010 from the International Cooperation and Exchange of the National Natural Science Foundation of China, grant 82071041 from the National Natural Science Foundation of China, grant 18DZ2260200 from the Shanghai Municipal Commission of Science and Technology, and grant 81530029 from the State Key Program of the National Natural Science Foundation of China.

    Role of the Funder/Sponsor: The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

    Additional Contributions: We would like to acknowledge all the participants and team members in this research. We thank Qiong Luo, MD, Yanyan Huang, MD, Chunyan Li, PhD, Yunyan Xia, PhD, Yang Guo, PhD, Ke Lai, PhD, Haosong Shi, PhD, Liang Xia, MD, Juanjuan Zou, PhD, Xinyi Li, PhD, Yingjun Qian, PhD, Min Liang, PhD, Yuyu Wang, PhD, Huiqun Jie, PhD, Zhipeng Li, PhD, Hengchao Chen, PhD, Shujian Huang, PhD, Mingxian Li, PhD, Liqiang Fan, MD, Lina Gong, PhD, Hanwei Liu, PhD, Qingxiu Yao, PhD, Fan Song, MD, Xiaolong Zhao, PhD, Yupu Liu, PhD, Jiajia Feng, PhD, Zhiyuan Song, MD, Zhen Zhang, PhD, Wenyue Xue, MD, Ru Tang, MD, Pengjun Wang, PhD, Fan Wang, PhD, Zhihui Fu, MD, Yuxin Tian, MD, Zhuangzhuang Li, MD, Zhenqi Liu, PhD, Guangyi Ba, MD, Jiajia Zhang, MD, and Qianqian Zhang, MD, all affiliated with the Otolaryngology Institute of Shanghai Jiao Tong University, for help with data acquisition. They were not compensated for their time.

    Additional Information: The data of this study are not publicly available due to the issue of intellectual property but are available from the corresponding author on reasonable request.

    References
    1.
    Gourévitch  B, Edeline  JM, Occelli  F, Eggermont  JJ.  Is the din really harmless? long-term effects of non-traumatic noise on the adult auditory system.   Nat Rev Neurosci. 2014;15(7):483-491. doi:10.1038/nrn3744PubMedGoogle ScholarCrossref
    2.
    Zhou  X, Merzenich  MM.  Environmental noise exposure degrades normal listening processes.   Nat Commun. 2012;3:843. doi:10.1038/ncomms1849PubMedGoogle ScholarCrossref
    3.
    Fitzgibbons  PJ, Gordon-Salant  S.  Temporal gap resolution in listeners with high-frequency sensorineural hearing loss.   J Acoust Soc Am. 1987;81(1):133-137. doi:10.1121/1.395022PubMedGoogle ScholarCrossref
    4.
    Moore  DR, Edmondson-Jones  M, Dawes  P,  et al.  Relation between speech-in-noise threshold, hearing loss and cognition from 40-69 years of age.   PLoS One. 2014;9(9):e107720. doi:10.1371/journal.pone.0107720PubMedGoogle Scholar
    5.
    Lin  FR, Albert  M.  Hearing loss and dementia—who is listening?   Aging Ment Health. 2014;18(6):671-673. doi:10.1080/13607863.2014.915924PubMedGoogle ScholarCrossref
    6.
    Sheppard  A, Ralli  M, Gilardi  A, Salvi  R.  Occupational noise: auditory and non-auditory consequences.   Int J Environ Res Public Health. 2020;17(23):E8963. doi:10.3390/ijerph17238963PubMedGoogle Scholar
    7.
    Rabinowitz  PM, Galusha  D, Slade  MD, Dixon-Ernst  C, Sircar  KD, Dobie  RA.  Audiogram notches in noise-exposed workers.   Ear Hear. 2006;27(6):742-750. doi:10.1097/01.aud.0000240544.79254.bcPubMedGoogle ScholarCrossref
    8.
    Nondahl  DM, Shi  X, Cruickshanks  KJ,  et al.  Notched audiograms and noise exposure history in older adults.   Ear Hear. 2009;30(6):696-703. doi:10.1097/AUD.0b013e3181b1d418PubMedGoogle ScholarCrossref
    9.
    Wilson  M, Reynolds  G, Kauppinen  RA, Arvanitis  TN, Peet  AC.  A constrained least-squares approach to the automated quantitation of in vivo 1H magnetic resonance spectroscopy data.   Magn Reson Med. 2011;65(1):1-12. doi:10.1002/mrm.22579PubMedGoogle ScholarCrossref
    10.
    Wilson  RH.  Some observations on the nature of the audiometric 4000 Hz notch: data from 3430 veterans.   J Am Acad Audiol. 2011;22(1):23-33. doi:10.3766/jaaa.22.1.4PubMedGoogle Scholar
    11.
    Sayler  SK, Roberts  BJ, Manning  MA, Sun  K, Neitzel  RL.  Patterns and trends in OSHA occupational noise exposure measurements from 1979 to 2013.   Occup Environ Med. 2019;76(2):118-124. doi:10.1136/oemed-2018-105041PubMedGoogle ScholarCrossref
    12.
    Coles  RR, Lutman  ME, Buffin  JT.  Guidelines on the diagnosis of noise-induced hearing loss for medicolegal purposes.   Clin Otolaryngol Allied Sci. 2000;25(4):264-273. doi:10.1046/j.1365-2273.2000.00368.xPubMedGoogle ScholarCrossref
    13.
    Knight  KR, Kraemer  DF, Winter  C, Neuwelt  EA.  Early changes in auditory function as a result of platinum chemotherapy: use of extended high-frequency audiometry and evoked distortion product otoacoustic emissions.   J Clin Oncol. 2007;25(10):1190-1195. doi:10.1200/JCO.2006.07.9723PubMedGoogle ScholarCrossref
    14.
    Yu  KK, Choi  CH, An  YH,  et al.  Comparison of the effectiveness of monitoring cisplatin-induced ototoxicity with extended high-frequency pure-tone audiometry or distortion-product otoacoustic emission.   Korean J Audiol. 2014;18(2):58-68. doi:10.7874/kja.2014.18.2.58PubMedGoogle ScholarCrossref
    15.
    Antonioli  CA, Momensohn-Santos  TM, Benaglia  TA.  High-frequency audiometry hearing on monitoring of individuals exposed to occupational noise: a systematic review.   Int Arch Otorhinolaryngol. 2016;20(3):281-289.PubMedGoogle Scholar
    16.
    Mehrparvar  AH, Mirmohammadi  SJ, Ghoreyshi  A, Mollasadeghi  A, Loukzadeh  Z.  High-frequency audiometry: a means for early diagnosis of noise-induced hearing loss.   Noise Health. 2011;13(55):402-406. doi:10.4103/1463-1741.90295PubMedGoogle ScholarCrossref
    17.
    Laffoon  SM, Stewart  M, Zheng  Y, Meinke  DK.  Conventional audiometry, extended high-frequency audiometry, and DPOAEs in youth recreational firearm users.   Int J Audiol. 2019;58(sup1):S40-S48. doi:10.1080/14992027.2018.1536833PubMedGoogle ScholarCrossref
    18.
    Liberman  MC, Kujawa  SG.  Cochlear synaptopathy in acquired sensorineural hearing loss: manifestations and mechanisms.   Hear Res. 2017;349:138-147. doi:10.1016/j.heares.2017.01.003PubMedGoogle ScholarCrossref
    19.
    Kujawa  SG, Liberman  MC.  Adding insult to injury: cochlear nerve degeneration after “temporary” noise-induced hearing loss.   J Neurosci. 2009;29(45):14077-14085. doi:10.1523/JNEUROSCI.2845-09.2009PubMedGoogle ScholarCrossref
    20.
    Ralli  M, Greco  A, De Vincentiis  M,  et al.  Tone-in-noise detection deficits in elderly patients with clinically normal hearing.   Am J Otolaryngol. 2019;40(1):1-9. doi:10.1016/j.amjoto.2018.09.012PubMedGoogle ScholarCrossref
    21.
    Prendergast  G, Couth  S, Millman  RE,  et al.  Effects of age and noise exposure on proxy measures of cochlear synaptopathy.   Trends Hear. 2019;23:2331216519877301. doi:10.1177/2331216519877301PubMedGoogle Scholar
    22.
    Fitzgibbons  PJ, Wightman  FL.  Gap detection in normal and hearing-impaired listeners.   J Acoust Soc Am. 1982;72(3):761-765. doi:10.1121/1.388256PubMedGoogle ScholarCrossref
    23.
    Shi  L, Chang  Y, Li  X, Aiken  S, Liu  L, Wang  J.  Cochlear synaptopathy and noise-induced hidden hearing loss.   Neural Plast. 2016;2016:6143164. doi:10.1155/2016/6143164PubMedGoogle Scholar
    24.
    Saunders  GH, Frederick  MT, Arnold  M, Silverman  S, Chisolm  TH, Myers  P.  Auditory difficulties in blast-exposed veterans with clinically normal hearing.   J Rehabil Res Dev. 2015;52(3):343-360. doi:10.1682/JRRD.2014.11.0275PubMedGoogle ScholarCrossref
    25.
    Schaette  R, McAlpine  D.  Tinnitus with a normal audiogram: physiological evidence for hidden hearing loss and computational model.   J Neurosci. 2011;31(38):13452-13457. doi:10.1523/JNEUROSCI.2156-11.2011PubMedGoogle ScholarCrossref
    26.
    Lobarinas  E, Salvi  R, Ding  D.  Selective inner hair cell dysfunction in chinchillas impairs hearing-in-noise in the absence of outer hair cell loss.   J Assoc Res Otolaryngol. 2016;17(2):89-101. doi:10.1007/s10162-015-0550-8PubMedGoogle ScholarCrossref
    27.
    Prendergast  G, Guest  H, Munro  KJ,  et al.  Effects of noise exposure on young adults with normal audiograms I: electrophysiology.   Hear Res. 2017;344:68-81. doi:10.1016/j.heares.2016.10.028PubMedGoogle ScholarCrossref
    28.
    Kujawa  SG, Liberman  MC.  Acceleration of age-related hearing loss by early noise exposure: evidence of a misspent youth.   J Neurosci. 2006;26(7):2115-2123. doi:10.1523/JNEUROSCI.4985-05.2006PubMedGoogle ScholarCrossref
    29.
    Villavisanis  DF, Schrode  KM, Lauer  AM.  Sex bias in basic and preclinical age-related hearing loss research.   Biol Sex Differ. 2018;9(1):23. doi:10.1186/s13293-018-0185-7PubMedGoogle ScholarCrossref
    30.
    Agrawal  Y, Niparko  JK, Dobie  RA.  Estimating the effect of occupational noise exposure on hearing thresholds: the importance of adjusting for confounding variables.   Ear Hear. 2010;31(2):234-237. doi:10.1097/AUD.0b013e3181c6b9fdPubMedGoogle ScholarCrossref
    31.
    Kujala  T, Shtyrov  Y, Winkler  I,  et al.  Long-term exposure to noise impairs cortical sound processing and attention control.   Psychophysiology. 2004;41(6):875-881. doi:10.1111/j.1469-8986.2004.00244.xPubMedGoogle ScholarCrossref
    32.
    Tepe  V, Papesh  M, Russell  S, Lewis  MS, Pryor  N, Guillory  L.  Acquired central auditory processing disorder in service members and veterans.   J Speech Lang Hear Res. 2020;63(3):834-857. doi:10.1044/2019_JSLHR-19-00293PubMedGoogle ScholarCrossref
    33.
    National Health and Family Planning Commission of the People’s Republic of China. Measurement of physical agents in the workplace—part 8: noise. November 9, 2007. Accessed August 3, 2021. https://www.chinesestandard.net/PDF/BOOK.aspx/GBZT189.8-2007
    34.
    Wong  LL, Soli  SD, Liu  S, Han  N, Huang  MW.  Development of the Mandarin Hearing in Noise Test (MHINT).   Ear Hear. 2007;28(2)(suppl):70S-74S. doi:10.1097/AUD.0b013e31803154d0PubMedGoogle ScholarCrossref
    35.
    Feng  Y, Yin  S, Kiefte  M, Wang  J.  Temporal resolution in regions of normal hearing and speech perception in noise for adults with sloping high-frequency hearing loss.   Ear Hear. 2010;31(1):115-125. doi:10.1097/AUD.0b013e3181bb69bePubMedGoogle ScholarCrossref
    36.
    Li  K, Xia  L, Zheng  Z,  et al.  A preliminary study on time-compressed speech recognition in noise among teenage students who use personal listening devices.   Int J Audiol. 2019;58(3):125-131. doi:10.1080/14992027.2018.1536298PubMedGoogle ScholarCrossref
    37.
    Korres  GS, Balatsouras  DG, Tzagaroulakis  A, Kandiloros  D, Ferekidis  E.  Extended high-frequency audiometry in subjects exposed to occupational noise.   B-ENT. 2008;4(3):147-155.PubMedGoogle Scholar
    38.
    Škerková  M, Kovalová  M, Mrázková  E.  High-frequency audiometry for early detection of hearing loss: a narrative review.   Int J Environ Res Public Health. 2021;18(9):4702. doi:10.3390/ijerph18094702PubMedGoogle ScholarCrossref
    39.
    Bharadwaj  HM, Masud  S, Mehraei  G, Verhulst  S, Shinn-Cunningham  BG.  Individual differences reveal correlates of hidden hearing deficits.   J Neurosci. 2015;35(5):2161-2172. doi:10.1523/JNEUROSCI.3915-14.2015PubMedGoogle ScholarCrossref
    40.
    Xiong  H, Chen  L, Yang  H,  et al.  Hidden hearing loss in tinnitus patients with normal audiograms: implications for the origin of tinnitus.  Article in Chinese.  Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi. 2013;27(7):362-365.PubMedGoogle Scholar
    41.
    Spankovich  C, Gonzalez  VB, Su  D, Bishop  CE.  Self-reported hearing difficulty, tinnitus, and normal audiometric thresholds, the National Health and Nutrition Examination Survey 1999-2002.   Hear Res. 2018;358:30-36.PubMedGoogle ScholarCrossref
    42.
    Grose  JH, Buss  E, Hall  JW  III.  Loud music exposure and cochlear synaptopathy in young adults: isolated auditory brainstem response effects but no perceptual consequences.   Trends Hear. 2017;21:2331216517737417. doi:10.1177/2331216517737417PubMedGoogle Scholar
    43.
    Fulbright  ANC, Le Prell  CG, Griffiths  SK, Lobarinas  E.  Effects of recreational noise on threshold and suprathreshold measures of auditory function.   Semin Hear. 2017;38(4):298-318. doi:10.1055/s-0037-1606325PubMedGoogle Scholar
    44.
    Prendergast  G, Millman  RE, Guest  H,  et al.  Effects of noise exposure on young adults with normal audiograms II: behavioral measures.   Hear Res. 2017;356:74-86. doi:10.1016/j.heares.2017.10.007PubMedGoogle ScholarCrossref
    45.
    Yeend  I, Beach  EF, Sharma  M, Dillon  H.  The effects of noise exposure and musical training on suprathreshold auditory processing and speech perception in noise.   Hear Res. 2017;353:224-236. doi:10.1016/j.heares.2017.07.006PubMedGoogle ScholarCrossref
    46.
    Guest  H, Munro  KJ, Prendergast  G, Millman  RE, Plack  CJ.  Impaired speech perception in noise with a normal audiogram: no evidence for cochlear synaptopathy and no relation to lifetime noise exposure.   Hear Res. 2018;364:142-151. doi:10.1016/j.heares.2018.03.008PubMedGoogle ScholarCrossref
    47.
    Valderrama  JT, Beach  EF, Yeend  I, Sharma  M, Van Dun  B, Dillon  H.  Effects of lifetime noise exposure on the middle-age human auditory brainstem response, tinnitus and speech-in-noise intelligibility.   Hear Res. 2018;365:36-48. doi:10.1016/j.heares.2018.06.003PubMedGoogle ScholarCrossref
    48.
    Lobarinas  E, Salvi  R, Ding  D.  Gap detection deficits in chinchillas with selective carboplatin-induced inner hair cell loss.   J Assoc Res Otolaryngol. 2020;21(6):475-483. doi:10.1007/s10162-020-00744-5PubMedGoogle ScholarCrossref
    49.
    Salvi  R, Sun  W, Ding  D,  et al.  Inner hair cell loss disrupts hearing and cochlear function leading to sensory deprivation and enhanced central auditory gain.   Front Neurosci. 2017;10:621. doi:10.3389/fnins.2016.00621PubMedGoogle ScholarCrossref
    50.
    Starr  A, Michalewski  HJ, Zeng  FG,  et al.  Pathology and physiology of auditory neuropathy with a novel mutation in the MPZ gene (Tyr145->Ser).   Brain. 2003;126(Pt 7):1604-1619. doi:10.1093/brain/awg156PubMedGoogle Scholar
    51.
    Fernandez  KA, Jeffers  PW, Lall  K, Liberman  MC, Kujawa  SG.  Aging after noise exposure: acceleration of cochlear synaptopathy in “recovered” ears.   J Neurosci. 2015;35(19):7509-7520. doi:10.1523/JNEUROSCI.5138-14.2015PubMedGoogle ScholarCrossref
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