Speech perception in noise, gap detection and amplitude modulation detection in suspected hidden hearing loss

Abstract

Objectives The objectives of the study were to investigate speech in noise perception, gap detection, and amplitude modulation detection in construction workers exposed to occupational noise, but had normal peripheral hearing. Hidden hearing loss characterized by suprathreshold processing deficits in the absence of affected hearing sensitivity was thus probed. Materials and methods Participants were 12 construction workers with chronic exposure to high levels of noise, but had hearing sensitivity and distortion product otoacoustic emissions within normal limits. The control group consisted of age-matched participants with no significant noise exposure. Speech in noise perception was assessed at 0 dB SNR using bi-syllabic words and Gap detection as well as Amplitude modulation detection were assessed with broadband noise. Results Speech in noise perception and Gap detection thresholds were significantly poorer in the noise-exposed group while Amplitude modulation detection performance did not differ significantly between the two groups. Conclusions Affected suprathreshold perception in the absence of peripheral hearing loss suggests the presence of a hidden hearing loss due to noise exposure. However, the disorder is subtle, and the variability is high, leading to heterogeneity in findings across studies. Studies with higher power and active replications are required to characterize cochlear synaptopathy better.