Auditory Deficits in Employees of Business Process Outsourcing (BPO): Need to Take Preventative Action.

The present study aimed to explore auditory deficits in full-time call center workers. A total of sixty participants participated, which was divided into two groups, viz. experimental group and control group. The complete audiological test battery was performed. On comparing the groups, significant differences were obtained for both ears while analyzing the TEOAEs, PTA1, and PTA2 (high-frequency audiometry). From the results, it can be delineated that BPO employees are at risk for sensorineural hearing loss following continuous noise exposure. We conclude that this type of hearing loss may be considered an iceberg, and to overcome all the issues related to noise exposure, all BPO employees should undergo periodic audiological, psychological, and health screening.

Occupational noise exposure, noise annoyance, hearing-related symptoms, and emotional exhaustion - a participatory-based intervention study in preschool and obstetrics care.

A participatory-based intervention was performed in Sweden, aimed at improving the sound environment in one preschool (n = 20) and one obstetric ward (n = 50), with two controls each (n = 28, n = 66). Measured sound levels, and surveys of noise annoyance, hearing-related symptoms and emotional exhaustion were collected before, and three and nine months after the interventions, comparing intervention and control groups over time. The results of this first implementation in a limited number of workplaces showed significantly worsening of hyperacusis, sound-induced auditory fatigue, emotional exhaustion and increased sound levels in the preschool, and worsening of noise annoyance in both intervention groups. Increased risk awareness, limited implementation support and lack of psychosocial interventions may explain the worsening in outcomes, as might the worse baseline in the intervention groups. The complexity of the demands in human-service workplaces calls for further intervention studies.

Parameters influencing auditory fatigue among professionals working in the amplified music sector: noise exposure and individual factors.

OBJECTIVE: Hearing disorders are common among music professionals, as they are frequently exposed to sound levels exceeding 100 dB(A). By assessing auditory fatigue, situations that are deleterious for hearing could be identified, allowing the deployment of preventive measures before permanent impairment occurs. However, little is known about the factors contributing to auditory fatigue. The objective is to determine the exposure parameters most influencing auditory fatigue during occupational exposure to amplified music. DESIGN: Auditory fatigue was defined as variations of both pure tone auditory (ΔPTA) and efferent reflex thresholds (ΔER) during the workday. Noise exposure was monitored and information on the volunteers was gathered using a questionnaire. STUDY SAMPLE: The population consisted of 43 adult volunteers exposed to amplified music (sound, light or stage technicians, security agents, barmen) and 24 unexposed administrative agents. RESULTS: ΔPTA and ΔER were positively correlated with the energy of noise exposure and its stability over time, i.e a steady noise tends to create more auditory fatigue. CONCLUSION: In addition to a global decrease of music levels and a systematic use of hearing protection, our results advocate for the provision of quiet periods within noise exposures as they reduce auditory fatigue accumulation and long-term risks for hearing.

Working in preschool increases the risk of hearing-related symptoms: a cohort study among Swedish women.

PURPOSE: To assess whether working in preschools increases the risk of hearing-related symptoms and whether age, occupational noise, and stressful working conditions affect the risk. METHODS: Questionnaire data on hearing-related symptoms were analysed in women aged 24-65 (4718 preschool teachers, and 4122 randomly selected general population controls). Prevalence and risk ratio (RR) of self-reported hearing loss, tinnitus, difficulty perceiving speech, hyperacusis and sound-induced auditory fatigue were assessed by comparing the cohorts in relation to age and self-reported occupational noise and stressful working conditions (effort-reward imbalance and emotional demands). RR was calculated using log-binomial regression models adjusted for age, education, income, smoking, hearing protection, and leisure noise. Incidence rates and incidence rate ratios (IRR) were calculated for retrospectively reported onset of all symptoms except sound-induced auditory fatigue. RESULTS: Compared to the controls, preschool teachers had overall more than twofold RR of sound-induced auditory fatigue (RR 2.4, 95% confidence interval 2.2-2.5) and hyperacusis (RR 2.3, 2.1-2.5) and almost twofold for difficulty perceiving speech (RR 1.9, 1.7-2.0). Preschool teachers had a threefold IRR of hyperacusis (IRR 3.1, 2.8-3.4) and twofold for difficulty perceiving speech (IRR 2.4, 2.2-2.6). Significantly although slightly less increased RR and IRR were observed for hearing loss and tinnitus. RR and IRR were generally still increased for preschool teachers when stratified by age and occupational exposure to noise and stress. CONCLUSIONS: This large cohort study showed that working as preschool teacher increases the risk of self-reported hearing-related symptoms, indicating a need of preventative measures.

Auditory fatigue among call dispatchers working with headsets.

OBJECTIVES: To determine whether call center dispatchers wearing headsets are subject to auditory fatigue at the end of a work shift. MATERIAL AND METHODS: Data was gathered at times when call centers were busiest. All call operators wore a headset for up to 12 h. Acoustic environment and noise exposure under the headset were continuously recorded during the entire work shift. Variations in auditory parameters were assessed using pure-tone air-conduction audiometry and an objective test based on distortion product otoacoustic emissions - contralateral suppression of distortion product otoacoustic emission (DPOAE) amplitudes (EchoScan test). Thirty-nine operators and 16 controls, all volunteers, were selected from 3 call centers (sales, assistance, and emergency) where all cognitive tasks were accomplished by phone and on computers. RESULTS: No acoustic shock was detected during the investigation. The highest normalized noise exposure (daily noise exposure level - LEX,8 h) measured was 75.5 dBA. No significant variation in auditory performances was detected with either pure-tone air-conduction audiometry or the EchoScan test. Nevertheless, dispatchers expressed a feeling of tiredness. CONCLUSIONS: For an equivalent diffuse field noise exposure, the use of a headset does not seem to worsen auditory fatigue for call center operators. The dispatcher's fatigue was probably due to the duration of the work shift or to the tasks they performed rather than to the noise exposure under a headset. Int J Occup Med Environ Health 2018;31(2):217-226.

Evaluation of the Auditory Pathway in Traffic Policemen.

BACKGROUND: Traffic policemen working at heavy traffic junctions are continuously exposed to high level of noise and its health consequences. OBJECTIVE: To assess the hearing pathway in traffic policemen by means of brainstem evoked response audiometry (BERA), mid-latency response (MLR), and slow vertex response (SVR). METHODS: In this observational comparative study, BERA, MLR, and SVR were tested in 35 male traffic policemen with field posting of more than 3 years. 35 age-matched men working in our college served as controls. RESULTS: Increase in the latencies of waves I and III of BERA, and IPL I-III were observed. Compared to controls, the MLR and SVR waves showed no significant changes in studied policemen. CONCLUSION: We found that chronic exposure of traffic policemen to noise resulted in delayed conduction in peripheral part of the auditory pathway, ie, auditory nerve up to the level of superior olivary nucleus; no impairment was observed at the level of sub-cortical, cortical, or the association areas.

Validating self-reporting of hearing-related symptoms against pure-tone audiometry, otoacoustic emission, and speech audiometry.

OBJECTIVE: To validate self-reported hearing-related symptoms among personnel exposed to moderately high occupational noise levels at an obstetrics clinic. DESIGN: Sensitivity, specificity, and predictive values were calculated for questionnaire items assessing hearing loss, tinnitus, sound sensitivity, poor hearing, difficulty perceiving speech, and sound-induced auditory fatigue. Hearing disorder was diagnosed by pure-tone audiometry, distortion product otoacoustic emissions, and HINT (Hearing In Noise Test). STUDY SAMPLE: Fifty-five female obstetrics personnel aged 22-63 participated; including 26 subjects reporting hearing loss, poor hearing, tinnitus, or sound sensitivity, and 29 randomly selected subjects who did not report these symptoms. RESULTS: The questionnaire item assessing sound-induced auditory fatigue had the best combination of sensitivity ≥85% (95% CIs 56 to 100%) and specificity ≥70% (95% CIs 55 to 84%) for hearing disorder diagnosed by audiometry or otoacoustic emission. Of those reporting sound-induced auditory fatigue 71% were predicted to have disorder diagnosed by otoacoustic emission. Participants reporting any hearing-related symptom had slightly worse measured hearing. CONCLUSIONS: We suggest including sound-induced auditory fatigue in questionnaires for identification of hearing disorder among healthcare personnel, though larger studies are warranted for precise estimates of diagnostic performance. Also, more specific and accurate hearing tests are needed to diagnose mild hearing disorder.

[Auditory fatigue]. / Fatiga auditiva.

INTRODUCTION AND OBJECTIVES: Given the relevance of possible hearing losses due to sound overloads and the short list of references of objective procedures for their study, we provide a technique that gives precise data about the audiometric profile and recruitment factor. Our objectives were to determine peripheral fatigue, through the cochlear microphonic response to sound pressure overload stimuli, as well as to measure recovery time, establishing parameters for differentiation with regard to current psychoacoustic and clinical studies. MATERIAL AND METHOD: We used specific instruments for the study of cochlear microphonic response, plus a function generator that provided us with stimuli of different intensities and harmonic components. In Wistar rats, we first measured the normal microphonic response and then the effect of auditory fatigue on it. RESULTS: Using a 60dB pure tone acoustic stimulation, we obtained a microphonic response at 20dB. We then caused fatigue with 100dB of the same frequency, reaching a loss of approximately 11dB after 15minutes; after that, the deterioration slowed and did not exceed 15dB. By means of complex random tone maskers or white noise, no fatigue was caused to the sensory receptors, not even at levels of 100dB and over an hour of overstimulation. CONCLUSIONS: No fatigue was observed in terms of sensory receptors. Deterioration of peripheral perception through intense overstimulation may be due to biochemical changes of desensitisation due to exhaustion. Auditory fatigue in subjective clinical trials presumably affects supracochlear sections. The auditory fatigue tests found are not in line with those obtained subjectively in clinical and psychoacoustic trials.

Assessment of impulse noise level and acoustic trauma in military personnel.

BACKGROUND: Military personnel are usually exposed to high levels of impulse noise (IN) which can lead to hearing loss. OBJECTIVES: The purpose of this study was to assess the effects of relatively low level exposure of impulse noise (IN) during shooting practice on hearing using pure tone audiometry (PTA) and transiently evoked otoacoustic emission (TEOAE) in military personnel. MATERIALS AND METHODS: Forty male soldiers (mean age 20.08 years) were recruited for the study. Prior to their first shooting practice, PTA and TEOAE were recorded. After 15 minutes and one week post- practice PTA and TEOAE were compared. RESULTS: Immediately after shooting practice significant differences in PTA at 500, 1000, and 4000 Hz were observed for the right ear and no significant difference at any frequency for the left ear. There was a significant difference in the amplitude of TEOAE 15 minutes after shooting practice at 500, 1000, 2000, 3000, and 4000 Hz in the right ear, while for the left ear the difference was significant at 1000 and 2000 Hz. One week after exposure a significant difference at 500 and 4000 Hz was found only in the right ear and a significant difference in the amplitude of TEOAE was observed at 500, 1000, 2000, 3000, and 4000 Hz. CONCLUSIONS: Even exposure lower than permissible levels may lead to acoustic trauma. TEOAE is more sensitive than PTA in detecting early hearing loss after military shooting exercises. Hearing protection equipment and appropriate surveillance programs are recommended.

The Relationship between the Change of Otoacoustic Emission and Temporary Threshold Shift after Broad Band Noise Stimulation / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: A distortion product otoacoustic emission (DPOAE) is a non-invasive method which is commonly used to assess the hearing function of the cochlea and to reflect objective information of specific frequency in the cochlea. We hypothesize that after applying a broad band noise (BBN), the outer hair cell's function will change and cause reduction in the amplitude of DPOAEs and signal to noise ratio (SNR). SUBJECTS AND METHOD: We performed the examination on 40 subjects (80 ears) who have a normal hearing function. DPOAEs were recorded before and after BBN stimulation (intensity: 90 dB HL, duration: 10 minutes). RESULTS: After the BBN stimulation, the amplitude of DPOAEs and SNR were decreased at all frequencies. The amplitude of DPOAEs and SNR decreased 0.3-1.6 dB SPL, 0.6-1.5 dB SPL, respectively. Decreases in the amplitude had statistical significances after 3 and 6 minutes in 1 kHz, 3 and 6 minutes in 2 kHz, immediately after noise exposure, and after 3 and 6 minutes in 6 kHz. However, the SNR changes had statistical significance only after 3 minutes in 1 kHz. After the stimulation, pure tone threshold at 4 kHz increased 3.2+/-3.9 dB HL. After the BBN exposure, the amplitude of DPOAEs and SNR decreased at all frequencies and most of them recovered within 12 minutes. CONCLUSION: These results suggest that DPOAE could be a clinically useful method for the purpose of screening, managing and assessing the prognosis of acoustic trauma and noise induced sensorineural hearing loss.