The timing of changes in parameters of speech production was investigated in six cochlear implant users by switching their implant microphones off and on a number of times in a single experimental session. The subjects repeated four short, two-word utterances, /dV₁n#SV₂d/ (S=/s/ or /ʃ/), in quasi-random order. The changes between hearing and nonhearing states were introduced by a voice-activated switch at V1 onset. "Postural" measures were made of vowel sound pressure level (SPL), duration, F0; contrast measures were made of vowel separation (distance between pair members in the formant plane) and sibilant separation (difference in spectral means). Changes in parameter values were averaged over multiple utterances, lined up with respect to the switch. No matter whether prosthetic hearing was blocked or restored, contrast measures for vowels and sibilants did not change systematically. Some changes in duration, SPL and F0 were observed during the vowel within which hearing state was changed, V1, as well as during V2 and subsequent utterance repetitions. Thus, sound segment contrasts appear to be controlled differently from the postural parameters of speaking rate and average SPL and F0. These findings are interpreted in terms of the function of hypothesized feedback and feedforward mechanisms for speech motor control.
Hearing aids, speech changes
Intelligibility of speech, Speech, Hearing
Speech and Hearing Science
Acoustical Society of America
This article may be downloaded for personal use only. Any other use requires prior permission of the author and the Acoustical Society of America.
©2007 Acoustical Society of America
Perkell, Joseph S.; Lane, Harlan; Denny, Margaret; Matthies, Melanie L.; Tiede, Mark; Zandipour, Majid; Vick, Jennell; and Burton, Ellen, "Time course of speech changes in response to unanticipated short-term changes in hearing state" (2007). Psychology Faculty Publications. Paper 21. http://hdl.handle.net/2047/d20000868
Click button above to open, or right-click to save.