Speech audiometry in noise: Signal noise ratio loss values according speech signal level presentation in normal hearing subjects

This study aimed to evaluate the psychometric function curve and signal-to-noise ratio (SNR) loss values during the "Vocale Rapide dans le Bruit" (VRB) speech-in-noise test with speech level presentations at 65dB SPL (VRB65) and 45dB SPL (VRB45) in normal-hearing subjects. Adult normal-hearing subjects underwent an audiological evaluation including tympanometry, pure-tone audiometry, speech recognition threshold in silence and speech-in-noise audiometry following the recommended protocol (65dB SPL, VRB65), followed by a second series of tests with a lower sentence presentation level (45dB SPL, VRB45). Among the 29 normal-hearing subjects, there was no significant variation in the psychometric function curves or SNR loss values for VRB65 or VRB45. The "Vocale Rapide dans le Bruit" speech-in-noise test is a relevant tool for assessing auditory difficulties in noisy environments. In normal-hearing subjects, presenting sentences at different intensity levels did not show a significant difference. This was an essential prerequisite for its use at various signal presentation levels, which could enable the evaluation of the functional state of high- and low-threshold auditory nerve fibers. This, in turn, would refine clinical diagnosis and improve the management of hearing disorders associated with hidden hearing loss.