Vowel production and perception in French blind and sighted adults

It is well known that visual cues play an important role in speech perception and production. Early in life, blind speakers, who do not have access to visual information related to lip and jaw movements, show a delay in the acquisition of phonological contrasts based on these visible articulatory features [A. E. Mills, Hearing by eye: The psychology of lip‐reading, pp. 145–161 (1987)]. It has also been claimed that blind speakers have better auditory discrimination abilities than sighted speakers. The goal of this study is to describe the production‐perception relationships involved in French vowels for blind and sighted speakers. Six blind adults and six sighted adults served as subjects. The auditory abilities of each subject were evaluated by auditory discrimination tests (AXB). At the production level, ten repetitions of the ten French oral vowels were recorded. Formant values and fundamental frequency values were extracted from the acoustic signal. Measures of contrasts (Euclidean distances) and dispersion (standard deviations) were computed and compared for each feature (height, place, roundedness) and group (blind, sighted). Regression analyses between discrimination scores and produced contrasts were carried out. Despite between‐speaker variability, results show an effect of speakers group (blind versus sighted) on the produced contrast distances.