Effects of hearing protector devices on speech intelligibility: the importance of individualized assessment

Abstract

Objectives. This study aimed to compare speech intelligibility in noise with and without hearing protection devices (HPDs). Methods. Fifty-one workers were distributed into three groups: noise-induced hearing loss group (NIHLG), normally hearing noise-exposed group (NG) and normally hearing non-exposed to noise group (CG). A free field system was used to emit monosyllables (65, 70 and 75 dB) and pink noise in different signal-to-noise ratios (SNRs) (0, −5, −10 and −15). Results. In situations with HPDs, all groups showed a decrease in the percentage of correct responses with an increase in noise level. The HPD had little effect on speech intelligibility in the NIHLG and NG. Considering the effect caused by the HPD on speech intelligibility, it was observed that the group with the greatest loss was the CG for SNRs of −5, −10 and −15. Conclusion. Although speech intelligibility is influenced by the hearing threshold, the noise level and SNR are crucial for good speech intelligibility, either with or without an HPD. It is highlighted that the NG had worse results when compared with the CG, which may indicate changes in the auditory pathway resulting from continuous noise exposure, even in the absence of changes in the audiometric thresholds.

Keywords:

• ear-protective devices
• noise
• occupational
• signal-to-noise ratio
• speech discrimination tests
• speech intelligibility

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplemental data and research materials

Supplemental data for this article can be accessed at https://doi.org/10.1080/10803548.2021.1880763.

Additional information

Funding

This work was supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior [Grant Number 001].