Effects of acoustic-phonetic access on audiovisual speech perception in children

Abstract

Visual speech helps compensate for degraded acoustic input, especially when redundancy between the accessible acoustic and visual cues is low. Recent findings indicate that children who are hard of hearing benefit more from visual speech than their peers with normal hearing, yet the two groups demonstrate similar speechreading ability. It is unclear whether this increased benefit reflects differences in auditory and multisensory development or differences in redundancy between the visual and acoustic cues available to each group. This study examines the extent to which acoustic-phonetic access (acoustic frequency content) influences auditory and audiovisual word recognition in children with normal hearing. Isolated word and word-in-sentence recognition accuracy are measured for auditory-only and audiovisual speech that were high-pass filtered and low-pass filtered with a 2 kHz cutoff frequency. Data collection is ongoing. We hypothesize that children will demonstrate greater audiovisual benefit when acoustic speech is low-pass filtered than when it is high-pass filtered, because low-frequency acoustic content is less redundant with visual speech cues than high-frequency acoustic content. These findings will elucidate whether acoustic-phonetic access can explain differences in audiovisual benefit between children with normal hearing and children who are hard of hearing. [Work supported by NIH R21DC020544.]