Acoustic and Perceptual Analysis of Speech through Electronic HPD in Noisy Situations

Abstract

Background: Globally, 16% of disabling hearing loss in adults is caused by occupational noise. Hearing Protection Devices (HPDs) successfully prevent occupational hearing loss to a marked extent. However, simultaneously, the use of HPDs hamper personal speech communication. Electronic HPDs are introduced to prevent the loss of communication while wearing HPDs. The present study aimed to measure the effect of electronic HPDs on acoustic and perceptual characteristics of speech. Method: The study procedure involved acoustic analysis and perceptual analysis. The speech stimuli in noise at different SNRs, with and without HPDs, were recorded using a sound level meter in a KEMAR for acoustic analysis. Perceptual analysis was done on 30 normal subjects; the subjects were asked to rate the naturalness and overall quality on a Likert rating scale, and listening effort was rated using a visual analog scale. Results: Acoustic analysis revealed a significant effect of HPD on the acoustic parameters, viz., pitch (SD), jitter, HNR, NHR, LTASS (α, β, γ) for words; pitch (SD), jitter, and LTASS (α, β, γ) for sentences, in the presence of speech babble noise. The acoustic characteristics of speech improved with HPD. The perceptual analysis also revealed a significant effect of HPD on the perception of speech naturalness, overall quality, and listening effort in different types of noise for different stimuli at different SNRs. However, the perception of speech was better without HPD than with HPD. Conclusion: These findings of the present study showed that the HPDs improve speech clarity through acoustic enhancements while introducing perceptual trade-offs that may affect user experience. These results highlight the effects of HPDs on speech perception, suggesting avenues for improving device design with speech communication needs in diverse listening conditions.