Effects of blindness on production–perception relationships: Compensation strategies for a lip-tube perturbation of the French [u]

ABSTRACT

The impact of congenital visual deprivation on speech production in adults was examined in an ultrasound study of compensation strategies for lip-tube perturbation. Acoustic and articulatory analyses of the rounded vowel /u/ produced by 12 congenitally blind adult French speakers and 11 sighted adult French speakers were conducted under two conditions: normal and perturbed (with a 25-mm diameter tube inserted between the lips). Vowels were produced with auditory feedback and without auditory feedback (masked noise) to evaluate the extent to which both groups relied on this type of feedback to control speech movements. The acoustic analyses revealed that all participants mainly altered F2 and F0 and, to a lesser extent, F1 in the perturbed condition – only when auditory feedback was available. There were group differences in the articulatory strategies recruited to compensate; while all speakers moved their tongues more backward in the perturbed condition, blind speakers modified tongue-shape parameters to a greater extent than sighted speakers.

KEYWORDS:

• Auditory feedback
• blindness
• compensations to perturbations
• speech production

Acknowledgments

The authors would like to thank the participants, Dominique Côté for her help in data processing, and Marlene Busko for copy-editing the paper.

Declaration of interest

The authors report having no conflict of interest. This research was supported by grants from the government of Canada's Social Science and Humanities Research Council (SSHRC) and the Natural Sciences and Engineering Research Council of Canada (NSERC).