How You Look Is What You Find: Observing the Phonology of Deaf Speakers

The types of phonological pattern which are found in the speech of deaf people have a particular relationship with speech intelligibility. This needs to be taken into account when assessing speech if the results of assessment are to be useful for effective decisions about intervention. The influence of visual perception is relevant for the assessment of all speakers with a hearing loss who are referred to in this article as ‘deaf people’. In addition, many deaf people use both a sign language and a spoken language. Spoken language intelligibility may be enhanced by loan features from the sign language concerned. Visual and auditory factors, phonetic and phonological levels, segmental and non-segmental features, and their potential interactions, need to be included when assessing speech production. The Phonological Evaluation and Transcription of Audio-visual Language (known as the PETAL Speech Assessment) allows these aspects of phonology to be considered differentially for different speakers. There are general implications of this approach for speech and language therapy.