The effect of cumulative noise exposure on distortion product otoacoustic emissions

Abstract

Objective

This study aimed to identify the characteristics of distortion product otoacoustic emissions (DPOAEs) that can be used to differentiate noise-induced hearing loss (NIHL) from age-related hearing loss. A potential index to detect NIHL was defined in terms of its susceptibility to cumulative noise exposure but not to age.

Design

In this cross-sectional cohort study, a job-exposure matrix was used to calculate the cumulative noise exposure. Multivariate linear regression models were used to examine how age and cumulative noise exposure associated with DPOAEs at individual frequencies after adjusting for hypertension, dyslipidaemia, tobacco use and alcohol consumption.

Study sample

The pure-tone audiometry and DPOAEs data collected from 239 male workers in a steel factory.

Results

DPOAEs and DPOAE signal-to-noise ratios (SNRs) at all frequencies were found to be correlated with age, and those at 2, 3, 4 and 6 kHz were correlated with both age and noise exposure. The difference between DPOAE SNR at 1 and 3 kHz showed significant correlation with noise exposure but not with age.

Conclusions

The results showed that this DPOAE index, the DPOAE SNR at 1 kHz minus the DPOAE SNR at 3 kHz, could add values to audiometric evaluation of NIHL.

Keywords:

• Hearing loss
• hearing impairment
• noise-induced hearing loss
• distortion product otoacoustic emission

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was financially supported by Taipei Medical University and Shuang Ho Hospital [grant no. 108TMU-SHH-17 and TMU108-AE1-B38]; Ministry of Science and Technology, Taiwan [grant no. 109-2314-B-038-022]; Institute of Occupational Safety and Health of the Council of Labor Affairs, Taiwan [grant no. IOSH96-M309] and National Cheng-Kung University Hospital [grant no. NCKUH-10702022].