The relative contribution of visual cues and acoustic enhancement strategies in improving speech perception of individuals with auditory neuropathy spectrum disorders

Abstract

Background and Objectives: The present study aimed to assess the relative benefits of visual cue supplementation and acoustic enhancement in improving speech perception of individuals with Auditory Neuropathy Spectrum Disorders (ANSD). Methods: The study utilized repeated measure research design. Based on the purposive sampling 40 participants with ANSD were selected. They were assessed for their speech identification of monosyllables in auditory only (A), visual only (V), and auditory-visual (AV) modalities. In the A and AV modalities, the perception of the primary, temporally enhanced, and spectrally enhanced syllables were assessed in quiet as well as 0 dB signal to noise ratio (SNR) conditions. The identification scores were compared across modalities, stimuli, and conditions to derive the relative benefits of visual cues and acoustic enhancement on speech perception of individuals with ANSD. Results: The group data showed a significant effect of modality with the mean identification score being the maximum in AV modality. This was true both in quiet and 0 dB SNR. The mean identification scores in quiet were significantly higher compared to that in 0 dB SNR. However, acoustic enhancement of speech did not significantly enhance speech perception. When acoustic enhancement and visual cues were simultaneously provided, speech perception was determined only by visual cues. The evidence from individual data showed that most of the individuals benefit from AV modality. Conclusions: The findings indicate that both auditory and visual modality needs to be facilitated in ANSD to enhance speech perception. The acoustic enhancements in the current form have negligible influence. However, the inference shall be restricted to the perception of stop consonants.