title: Speaking Clearly for the Blind: Acoustic and Articulatory Correlates of Speaking Conditions in Sighted and Congenitally Blind Speakers.
abstract: Compared to conversational speech, clear speech is produced with longer vowel duration, greater intensity, increased contrasts between vowel categories, and decreased dispersion within vowel categories. Those acoustic correlates are produced by larger movements of the orofacial articulators, including visible (lips) and invisible (tongue) articulators. Thus, clear speech provides the listener with audible and visual cues that are used to increase the overall intelligibility of speech produced by the speaker. It is unclear how those cues are produced by visually impaired speakers who never had access to vision. In this paper, we investigate the acoustic and articulatory correlates of vowels in clear versus conversational speech, and in sighted and congenitally blind speakers. Participants were recorded using electroarticulography while producing multiple repetitions of the ten Quebec French oral vowels in carrier sentences in both speaking conditions. Articulatory variables (lip, jaw, and tongue positions) as well as acoustic variables (contrasts between vowels, within-vowel dispersion, pitch, duration, and intensity) were measured. Lip movements were larger when going from conversational to clear speech in sighted speakers only. On the other hand, tongue movements were affected to a larger extent in blind speakers compared to their sighted peers. These findings confirm that vision plays an important role in the maintenance of speech intelligibility.
authors.affiliation: Laboratoire de Phonétique, Université du Québec à Montréal, Center For Research on Brain, Language, and Music, Montreal, Quebec, Canada.
authors.forename: Lucie
authors.initials: L
authors.lastname: Ménard
authors.affiliation: Laboratoire de Phonétique, Université du Québec à Montréal, Center For Research on Brain, Language, and Music, Montreal, Quebec, Canada.
authors.forename: Pamela
authors.initials: P
authors.lastname: Trudeau-Fisette
authors.affiliation: Laboratoire de Phonétique, Université du Québec à Montréal, Center For Research on Brain, Language, and Music, Montreal, Quebec, Canada.
authors.forename: Dominique
authors.initials: D
authors.lastname: Côté
authors.affiliation: Laboratoire de Phonétique, Université du Québec à Montréal, Center For Research on Brain, Language, and Music, Montreal, Quebec, Canada.
authors.forename: Christine
authors.initials: C
authors.lastname: Turgeon
mesh_terms: D000328:Adult; D000368:Aged; D001766:Blindness / Q000453:epidemiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011792:Quebec / Q000453:epidemiology; D013061:Speech Acoustics; D013062:Speech Articulation Tests; D013065:Speech Intelligibility; D013067:Speech Perception; D013068:Speech Production Measurement; D019987:Persons with Visual Disabilities