Predicting hearing thresholds and occupational hearing loss with multiple-frequency auditory steady-state responses.

Area of Science:

• Audiology
• Occupational Health
• Otoacoustic Emissions

Background:

• Work-related noise exposure can cause sensorineural hearing loss (SNHL).
• Objective hearing assessment is crucial for medicolegal arbitration of noise-induced hearing loss (NIHL).
• Multiple-frequency auditory steady-state responses (Mf-ASSRs) offer an objective measure of hearing thresholds.

Purpose of the Study:

• To investigate the accuracy of Mf-ASSRs in individuals with SNHL, comparing those with and without occupational noise exposure.
• To evaluate Mf-ASSRs as a tool for medicolegal assessment of NIHL.
• To develop a predictive equation for hearing thresholds using Mf-ASSRs.

Main Methods:

• A cross-sectional study was conducted at a tertiary referral medical center.
• Pure-tone audiometry and Mf-ASSRs were performed on 88 subjects: 34 with NIHL, 36 with SNHL without noise exposure, and 18 normal controls.
• Inter- and intragroup comparisons were made, and multiple linear regression analysis was used to derive a predictive equation.

Main Results:

• A strong correlation was found between Mf-ASSRs and pure-tone thresholds (PTTs) across all subjects (r = .77–.94).
• The difference between Mf-ASSRs and PTTs was significantly greater in the NIHL group compared to the non-noise-induced SNHL group (p < .001).
• A predictive equation was derived to estimate hearing thresholds.

Conclusions:

• Mf-ASSR is a promising objective tool for hearing threshold evaluation.
• The predictive value of Mf-ASSR may be reduced in cases of occupational hearing loss.
• Mf-ASSR can aid in detecting auditory pathway injury from noise exposure and assist in medicolegal evaluations.