Detection Of Noise-induced Hearing Loss Research Articles

Predictive value of serum proteomic biomarkers for noise-induced hearing loss.

Early detection of noise-induced hearing loss (NIHL) in patients with long-term noise exposure is vital for improving public health and reducing social burden. However, at present, the diagnosis of NIHL mainly depends on audiometric testing, and the primary test is pure-tone audiometry. Moreover, testing requires professional operators and complex equipment; thus, NIHL is often diagnosed at a later disease stage. Using a liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomic approach, we identified 9 differentially expressed proteins (DEPs), namely, 6 upregulated serum proteins and 3 downregulated serum proteins, in samples from 50 ground crew personnel working at an air force station. Then, according to the results, we predicted that caldesmon (CALD1), myocilin (MYOC), zyxin (ZYX), creatine kinase M-type (CKM), insulin-like growth factor-binding protein 2 (IGFBP2), complement factor H-related protein 4 (CFHR4), prenylcysteine oxidase 1 (PCYOX1), heat shock cognate 71 kDa protein (HSPA8), and immunoglobulin lambda variable 3-21 (IGLV3-21) were associated with NIHL. We selected these DEPs as variables to perform logistic regression. Finally, a logistic regression model was constructed based on IGFBP2, ZYX, CKM, and CFHR4. The area under the curve was 0.894 (95% CI = 0.812 to 0.977). These findings suggested that IGFBP2, ZYX, CKM, and CFHR4 in serum are differentially expressed in NIHL patients and have the potential to be biomarkers for predicting the risk for NIHL. Further experiments in mice showed that ZYX and IGFBP2 in the cochlear were increased after noise exposure. ZYX and IGFBP2 may be involved in the occurrence and development of NIHL.

Early detection of noise-induced hearing loss.

BACKGROUNDNoise-induced hearing loss (NIHL) is the second most common acquired hearing loss following presbycusis. Exposure to recreational noise and minimal use of hearing protection increase the prevalence of NIHL in young females. NIHL is irreversible. Identifying minor hearing pathologies before they progress to hearing problems that affect daily life is crucial.AIMTo compare the advantages and disadvantages of extended high frequency (EHF) and otoacoustic emission and determine an indicator of hearing pathologies at the early sub-clinical stage. METHODSThis cross-sectional study was implemented in West China Hospital of Sichuan University from May to September 2019. A total of 86 participants, aged 18-22 years, were recruited to establish normative thresholds for EHF. Another 159 adults, aged 18-25 years with normal hearing (0.25-8 kHz ≤ 25 dBHL), were allocated to low noise and noise exposure groups. Distortion otoacoustic emission (DPOAE), transient evoked otoacoustic emissions (TEOAE), and EHF were assessed in the two groups to determine the superior technique for detecting early-stage noise-induced pathologies. The chi-square test was used to assess the noise and low noise exposure groups with respect to extended high-frequency audiometry (EHFA), DPOAE, and TEOAE. P ≤ 0.05 was considered statistically significant.RESULTSA total of 86 participants (66 females and 20 males) aged between 18 and 22 (average: 20.58 ± 1.13) years were recruited to establish normative thresholds for EHF. The normative thresholds for 9, 10, 11.2, 12.5, 14, 16, 18, and 20 kHz were 15, 10, 20, 15, 15, 20, 28, and 0 dBHL, respectively. A total of 201 participants were recruited and examined for eligibility. Among them, 159 adults aged between 18 and 25 years were eligible in this study. No statistical difference was detected between the noise exposure and the low noise exposure groups using EHFA, DPOAE, and TEOAE (P > 0.05) except in the right ear at 4 kHz using TEOAE (abnormal rate 20.4% vs 5.2%, respectively; P = 0.05).CONCLUSIONThese results showed TEOAE as the earliest indicator of minor pathology compared to DPOAE and EHFA. However, a multicenter controlled study or prospective study is essential to verify these results.

High-Frequency Audiometry in Women with and without Exposure to Workplace Noise.

For this study, high-frequency audiometry was used to compare the hearing thresholds, with respect to age, among women exposed to noise in their working environment, as well as those not exposed to such noise. The cohort comprised 243 women (average age 36.2 years), of which 88 women were employed in a noisy (LAeq,8h 85–105 dB) workplace, while 155 women did not experience noise. Age categories were determined according to the World Health Organization (Geneva, Switzerland). Hearing thresholds were measured at frequencies of 0.125–16 kHz. Higher hearing thresholds were found in the youngest age groups (18–29 and 30–44 years) among those exposed to noise, as compared to those who were not. The difference in hearing thresholds between the exposed and unexposed groups increased with age, as well as with the frequencies. The highest difference in hearing thresholds for these age categories was measured at 11.25 kHz. The oldest age group (45–63 years) exposed to noise showed lower hearing thresholds than the unexposed group at all frequencies from 4 kHz to 16 kHz. High-frequency audiometry can be used for the early detection of increased hearing thresholds at high frequencies. High-frequency audiometry could be included in preventive programs, especially for younger people exposed to noise, in order to enable earlier detection of noise-induced hearing loss.

Implementation of a method to visualize noise-induced hearing loss in mass stranded cetaceans

Assessment of the impact of noise over-exposure in stranded cetaceans is challenging, as the lesions that lead to hearing loss occur at the cellular level and inner ear cells are very sensitive to autolysis. Distinguishing ante-mortem pathology from post-mortem change has been a major constraint in diagnosing potential impact. Here, we outline a methodology applicable to the detection of noise-induced hearing loss in stranded cetaceans. Inner ears from two mass strandings of long-finned pilot whales in Scotland were processed for scanning electron microscopy observation. In one case, a juvenile animal, whose ears were fixed within 4 hours of death, revealed that many sensory cells at the apex of the cochlear spiral were missing. In this case, the absence of outer hair cells would be compatible with overexposure to underwater noise, affecting the region which transduces the lowest frequencies of the pilot whales hearing spectrum. Perfusion of cochlea with fixative greatly improved preservation and enabled diagnostic imaging of the organ of Corti, even 30 hours after death. This finding supports adopting a routine protocol to detect the pathological legacy of noise overexposure in mass stranded cetaceans as a key to understanding the complex processes and implications that lie behind such stranding events.

High-frequency audiometry in normal hearing military firemen exposed to noise

The study of high frequencies has proven its importance for detecting inner ear damage. In some cases, conventional frequencies are not sensitive enough to pick up early changes to the inner ear.AimTo analyze the results of threshold high frequency analysis of individuals exposed to noise with normal conventional audiometry.Materials and MethodsThis was a retrospective cross-sectional cohort study, in which we studied 47 firefighters of the Fire Department of Rio de Janeiro, based on Santos Dumont airport and 33 military men without noise exposure. They were broken down into two age groups: 30-39years and 40-49years. The high frequencies were studied immediately after conventional audiometry.ResultsThe results were most significant in the 40 to 49 years of age range, where the experimental group showed significantly higher threshold values than the control group 14000Hz (p = 0.008) and 16,000Hz (p = 0.0001).ConclusionsWe concluded that noise interfered with high frequency thresholds, where all the mean values found in the experimental group were higher than those in the control group. We suggest that these data reinforce the importance of studying high frequencies, even with normal conventional audiometry in the early detection of noise-induced hearing loss.

An Assessment of Threshold Shifts in Nonprofessional Pop/Rock Musicians Using Conventional and Extended High-Frequency Audiometry

The clinical value of extended high-frequency audiometry for the detection of noise-induced hearing loss has not been established conclusively. The purpose of this study was to assess the relative temporary threshold shift (TTS) in two frequency regions (conventional versus extended high frequency). In this exploratory study, pure-tone thresholds from 0.5 to 14 kHz were measured in both ears of 16 nonprofessional pop/rock musicians (mean age, 35 yr; range, 27 to 49 yr), before and after a 90-minute rehearsal session. All had experienced repeated exposures to intense sound levels during at least 5 yr of their musical careers. After the rehearsal, median threshold levels were found to be significantly poorer for frequencies from 0.5 to 8 kHz (Wilcoxon signed rank test, p <or= 0.004) but were unchanged in the extended high-frequency range from 9 to 14 kHz. Decreases in the median threshold values measured before the rehearsal were present across the conventional frequency range, most notably at 6 kHz, but were not observed in the extended high-frequency range. On the basis of these results, extended high-frequency audiometry does not seem advantageous as a means of the early detection of noise-induced hearing loss.

Risk of Damage to Hearing from Personal Listening Devices in Young Adults

To investigate the effects of personal listening device use on hearing in young listeners. Conventional frequency audiometry (0.5-8 kHz) and extended high-frequency audiometry (10-20 kHz) were performed on 120 personal listening device users and 30 normal-hearing young adults. The hearing thresholds in the 3 to 8 kHz frequency range were significantly increased in the personal listening device listeners. The frequency range of the increased thresholds became broad as the exposure duration was increased. Impaired hearing was detected in 14.1% (34 of 240 ears) of ears (> 25 dB HL in one or more frequencies in 0.5-8 kHz). The hearing thresholds of extended high-frequency audiometry in personal listening device users could also be increased even if their hearing thresholds in conventional frequency audiometry were normal. Our results suggest that long-term use of personal listening devices can impair hearing function The data also indicate that extended high-frequency audiometry is a sensitive method for early detection of noise-induced hearing loss.

Extratympanic electrocochleographic changes on noise-induced temporary threshold shift

Objective Electrocochleography (ECoG) is a sensitive evoked-response test for evaluating changes in cochlear function. We investigated the extratympanic ECoG in a noise-induced temporary threshold shift (TTS) to evaluate the usefulness of ECoG in the early detection of noise-induced hearing loss (NIHL). Study design and methods In a prospective analysis, 15 healthy ears were exposed to 90.3- to 105.0-dB noise for 3 hours in the same computer-game arcade. Pure-tone audiometry and ECoG were performed before, immediately after, and 24 hours after the exposure. Results Before the exposure, the average hearing level was 5.8 ± 2.7 dB, which increased significantly to 12.8 ± 2.8 dB immediately after exposure. A marked increment in the SP/AP (summating potential/action potential) ratio was observed with the TTS. The mean ratio was 0.22 ± 0.11 before the exposure, 0.46 ± 0.18 in the TTS phase, and 0.20 ± 0.11 after resolution. Conclusion The results of this study suggest that the SP/AP ratio is useful for the early detection and monitoring of NIHL.

THE LIKELIHOOD OF DETECTING A SIGNIFICANT HEARING THRESHOLD SHIFT AMONG NOISE-EXPOSED WORKERS SUBJECTED TO ANNUAL; AUDIOMETRIC TESTING

The ability of annual audiometric surveillance to detect significant deteriorations in hearing sensitivity is examined considering the time pattern of the growth of noise-induced hearing loss. The yearly rate of change in hearing level due to the effects of noise exposure and age is computed from a mathematical model put forward in the International Standard ISO 1999 (1989). The first-order derivative of hearing level associated with noise and age was compared with different criteria of significant threshold shift (STS). The results show that the potential annual variation in hearing level at 4 kHz, the audiometric frequency most affected by noise, is always less than the minimum margin of error of audiometry under exposure to 90 dBA-8 h. At 100 dBA it nearly equals the margin of error only for the very first year of exposure and for the most sensitive individuals. The rate of change in hearing threshold at 4 kHz is less than or equal to 1 dB per year for a major portion of a population exposed to an average noise level of 90 dBA-8 h (+/- 5 dB SD). For other audiometric frequencies, or for combinations of frequencies, this rate is even lower. It is also demonstrated that, using annual hearing tests, the likelihood of measuring an STS in a noise-exposed population is very small. It would be nearly equal to the likelihood of some workers being exposed to 100 dBA-8 h or more for a first year. Such results throw doubt on the validity of audiometric surveillance as a procedure for early detection of noise-induced hearing loss. They also imply that the detection by audiometric tests of true cases of significant threshold shift due to noise is excessively expensive.

騒音性聴力損失者のコムニケーション障害に関する研究

Up to the present social evaluation of the degree of hearing loss is made by the average threshold values for several, pure tones involved in the acoustic range related to speech. This average indicates numerically only a qualitative aspect of the communication capacity. The language used in our daily life is formed by tones of various frequencies and intensities. Accordingly, the degree of actual competence of communication can not simply. be indicated by such average values. Threshold is the sound-level which is just noticeable. Therefore, the scale related to easiness for hearing should be included into the social evaluation on the degree of hearing loss.From the above-mentioned view point, this study was made for clarifying the relationship between the auditory threshold and the most comfortable loudness level (MCL) elicitable by pure-tone and speech audiometry. And more over a classification on 20 monosyllables was made by using the “hard-easy” scale for listening. The subjects were 124 male workers (248 ears) engaged in noisy work-shops. Noise levels in these work-shops were 90 dB (A) or over.The following results were obtained : (1) High positive correlations were found between the threshold at 4000 Hz and those at 3000 and 6000 Hz, and between the threshold at 1000 Hz and those at 500 and 2000 Hz. From these facts, 1000 Hz and 4000 Hz were useful test-frequencies for early detection of noise-induced hearing loss.(2) High positive correlation between the threshold and MCL was found in at each frequency, especially in high frequencies.(3) Inverse correlation was found as significant between the threshold and MCL-threshold. That is, a recruitment phenomenon was observed in workers with noise-induced hearing loss.(4) The auditory threshold at which MCL begins to increase significantly above the normal MCL level was 30 dB at 4000 Hz and 0 dB at the average frequency value (C2+2C3+C4) /4 or (C2+2C3+2C4+C5) /6.The auditory threshold at which the impairment of communication in daily life begins was 50 dB at 4000 Hz, 0 dB at the average value (C2+2C3+C4) /4, and 20 dB at the average value (C2+ 2C3+2C4+C5) /6.(5) Monosyllables listened easily were “A”, “Wa”, “To” and “O”, while those hard of listening were “Ji”, “Ki”, “Ne”, “Su”, “Shi”, “Te” and “Ri”.(6) Monosyllables with which the subjects frequently tended to confused were as follows : “Ha”, “Ta”, “Mo”, “Ba”, “Ga”, “Te” and “Ne”. The confusion was mainly related to the consonant coming at the top of the word.(7) In the examination of articulation of the monosyllables at the minimum intelligible level, “Ni”, “Shi”, “Ga”, “Ki” and “Su” showed higher rates in subjects with normal auditory threshold than in those with hearing loss.(8) In the examination of articulation of the monosyllables at MCL (for sentence), “Ki”, “Su”, “Te” and “Ji” showed higher rate in subjects with normal auditory threshold than in those with hearing loss.(9) In the examination of MCL for monosyllables, those monosyllables which showed the same pattern mentioned above were “Ni”, “Su” and “Ji”, but “Ri” showed significantly lower articulation rate in subjects with hearing loss.