Compensation to articulatory perturbation: Perceptual data

Abstract

The perceptual adequacy of vowels, stop consonants, and fricatives produced under conditions of articulatory perturbation was explored. In a previous study [McFarland and Baum, J. Acoust. Soc. Am. 97, 1865-1873 (1995)], acoustic analyses of segments produced in two subtests (immediate compensation and postconversation) revealed small but significant changes in spectral characteristics of vowels and consonants under bite-block as compared to normal conditions. For the vowels only, adaptation increased subsequent to a period of conversation with the bite block in place, suggesting that compensation may develop over time and that consonants may require a longer period of adaptation. The present follow-up investigation examined whether the acoustic differences across conditions were perceptually salient. Ten listeners performed an identification and a quality rating task for stimuli from the earlier acoustic study. Results revealed reductions in identification scores and quality ratings for a subset of the vowels and consonants in the bite-block conditions relative to the normal condition in the immediate compensation subtest. In the postconversation subtest, quality ratings for the fricatives in the bite-block condition remained low as compared to those in the normal condition. Perceptual results are compared to the previous acoustic data gathered on these stimuli.

Voice responses to changes in pitch of voice or tone auditory feedback

“…Such compensatory behavior and error correction have also been observed in other sensory and motor systems including the visual, auditory, and articulatory systems (Baum et al, 1996;Cole and Abbs, 1988;Gracco and Abbs, 1985;Held, 1965;Shaiman and Gracco, 2002). In an investigation on the role of auditory adaptation in the speech domain, human subjects were provided auditory feedback in which the vowel formants being produced were shifted slowly over time (Houde and Jordan, 1998).…”

Learning to produce speech with an altered vocal tract: The role of auditory feedback

“…For example, Honda and Kaburagi ͑2000͒ tracked compensations made to dynamical structural perturbations of the palate shape while we imposed a static perturbation. Recovery from other static perturbations such as the restriction of articulator movement with a bite block is enhanced by the presence of auditory feedback ͑e.g., Hoole, 1987;Flege et al, 1988;McFarland and Baum, 1995;Baum, McFarland, and Diab, 1996;McFarland et al, 1996͒. Even in the absence of vocal-tract modifications, auditory feedback has been shown to increase the precision with which speech categories are produced. For instance, studies of cochlear implant patients for whom feedback can be directly manipulated by turning the implanted device on and off have shown rapid modifications in speaking level, F 0 , and vowel formants ͑Svirsky and Tobey, 1991͒.…”

fMRI investigation of unexpected somatosensory feedback perturbation during speech

“…Despite the large number of behavioral studies that have utilized static and dynamic perturbations to the articulators (e.g., Abbs and Gracco, 1984; Baum et al, 1996; Baum et al, 1997; Baum, 1999; Folkins and Abbs, 1975; Folkins and Zimmerman, 1982; Gay et al, 1981; Gomi et al, 2002; Gracco and Abbs, 1985; Jacks, 2008; Kelso et al, 1984; Lane et al, 2005; Lindblom et al, 1979; McFarland and Baum, 1995; Nasir and Ostry, 2006, 2008, 2009; Tremblay et al, 2003), few researchers have attempted to use non-invasive imaging techniques to investigate the neural substrates underlying the somatosensory feedback control of fluent speech production. Part of the challenge is that a device must be created that not only perturbs subjects’ articulator movements, but is also MR compatible.…”