Acoustic and articulatory analysis of French vowels produced by congenitally blind adults and sighted adults

Abstract

In a previous paper [M enard et al., J. Acoust. Soc. Am. 126, 1406-1414(2009, it was demonstrated that, despite enhanced auditory discrimination abilities for synthesized vowels, blind adult French speakers produced vowels that were closer together in the acoustic space than those produced by sighted adult French speakers, suggesting finer control of speech production in the sighted speakers. The goal of the present study is to further investigate the articulatory effects of visual deprivation on vowels produced by 11 blind and 11 sighted adult French speakers. Synchronous ultrasound, acoustic, and video recordings of the participants articulating the ten French oral vowels were made. Results show that sighted speakers produce vowels that are spaced significantly farther apart in the acoustic vowel space than blind speakers. Furthermore, blind speakers use smaller differences in lip protrusion but larger differences in tongue position and shape than their sighted peers to produce rounding and place of articulation contrasts. Trade-offs between lip and tongue positions were examined. Results are discussed in the light of the perception-for-action control theory.

Maintaining Distinctiveness at Increased Speaking Rates: A Comparison between Congenitally Blind and Sighted Speakers

“…This pattern was also found in our previous studies of speech production in blind speakers [16,17,23]. Furthermore, as expected, vowels produced in the fast speech condition were significantly shorter than those produced in the normal speech condition (F[1,17] = 68.75; p < 0.01; η 2 = 0.79).…”

“…These results can be interpreted in the light of the multimodal cues that speakers transmit to their perceivers while they move their lips and jaw during speech production. We have reported elsewhere [17,23] that visible articulatory gestures (lip and jaw movements) are more heavily weighted in the phonological representations of sighted speakers, compared to their blind peers. When required to enhance distinctiveness, such as in a clear speech condition, sighted speakers increase the amplitude of lip and jaw movements more than blind speakers, presumably to enhance audiovisual perceptual saliency.…”

“…When required to enhance distinctiveness, such as in a clear speech condition, sighted speakers increase the amplitude of lip and jaw movements more than blind speakers, presumably to enhance audiovisual perceptual saliency. Congenitally blind speakers who have never had access to visual cues, do not use these articulators to the same extent; instead, they use tongue movements more to enhance saliency [17]. In the current experiment, speakers were asked to talk at an increased rate, a condition that jeopardizes distinctiveness.…”

“…Twenty participants were recruited from our previous studies [2,16,17]. Ten congenitally blind adults (5 males and 5 females) and 10 sighted adult control speakers (6 males and 4 females) participated in the study.…”

Effects of Congenital Visual Deprivation on the Auditory Perception of Anticipatory Labial Coarticulation

“…Participants were Quebec French congenitally blind adults who had taken part in previous speech perception and production experiments conducted in our laboratory [10,12,13]. Age-matched sighted adults were also tested.…”