Audiovisual Speech Perception in People with Hearing Loss across Languages: A Systematic Review of English and Mandarin

Abstract

Audiovisual (AV) information has been reported to facilitate speech understanding among the English-speaking population. However, it is not clear whether audiovisual benefits also exist among people who speak languages other than English. A systematic review was conducted to investigate the audiovisual effects on speech perception among people with hearing loss who speak English and people with hearing loss who speak Mandarin. The results of the review demonstrated audiovisual benefits in the English-speaking population with hearing loss regardless of age, degree of hearing loss, use and type of hearing technology, and acoustic environment. By contrast, significant audiovisual benefits were only found for Mandarin phoneme and word recognition but not for tone recognition in pre-lingually deafened adults with cochlear implants and for phoneme recognition in children with hearing aids. No significant audiovisual benefits were revealed in Mandarin-speaking post-lingually deafened adults with cochlear implants and for speech perception at higher intensity levels. Heterogeneity in the results across studies and limitations of the included studies were discussed.