Representation of the vocal roughness of aperiodic speech sounds in the auditory cortex.
Aperiodicity of speech alters voice quality. The current study investigated the relationship between vowel aperiodicity and human auditory cortical N1m and sustained field (SF) responses with magnetoencephalography. Behavioral estimates of vocal roughness perception were also collected. Stimulus aperiodicity was experimentally varied by increasing vocal jitter with techniques that model the mechanisms of natural speech production. N1m and SF responses for vowels with high vocal jitter were reduced in amplitude as compared to those elicited by vowels of normal vocal periodicity. Behavioral results indicated that the ratings of vocal roughness increased up to the highest jitter values. Based on these findings, the representation of vocal jitter in the auditory cortex is suggested to be formed on the basis of reduced activity in periodicity-sensitive neural populations.
Department of Signal Processing and Acoustics, Helsinki University of Technology, P.O. Box 3000, FI-02015 TKK, Finland. santeri.yrttiaho@tkk.fi
Santeri
S
Yrttiaho
Paavo
P
Alku
Patrick J C
PJ
May
Hannu
H
Tiitinen
D000161:Acoustic Stimulation; D000328:Adult; D000704:Analysis of Variance; D001303:Auditory Cortex / Q000502:physiology*; D005072:Evoked Potentials, Auditory; D005260:Female; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D010700:Phonetics; D013060:Speech; D013061:Speech Acoustics; D013067:Speech Perception / Q000502:physiology*; D013997:Time Factors; D014833:Voice Quality