title: Cortical processing of speech sounds and their analogues in a spatial auditory environment.
abstract: We used magnetoencephalographic (MEG) measurements to study how speech sounds presented in a realistic spatial sound environment are processed in human cortex. A spatial sound environment was created by utilizing head-related transfer functions (HRTFs), and using a vowel, a pseudo-vowel, and a wide-band noise burst as stimuli. The behaviour of the most prominent auditory response, the cortically generated N1m, was investigated above the left and right hemisphere. We found that the N1m responses elicited by the vowel and by the pseudo-vowel were much larger in amplitude than those evoked by the noise burst. Corroborating previous observations, we also found that cortical activity reflecting the processing of spatial sound was more pronounced in the right than in the left hemisphere for all of the stimulus types and that both hemispheres exhibited contralateral tuning to sound direction.
authors.affiliation: Speech and Hearing Research Group, Department of Computer Science, University of Sheffield, Sheffield, UK. kalle.palomaki@hut.fi
authors.forename: Kalle J
authors.initials: KJ
authors.lastname: Palomäki
authors.forename: Hannu
authors.initials: H
authors.lastname: Tiitinen
authors.forename: Ville
authors.initials: V
authors.lastname: Mäkinen
authors.forename: Patrick
authors.initials: P
authors.lastname: May
authors.forename: Paavo
authors.initials: P
authors.lastname: Alku
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D000328:Adult; D000704:Analysis of Variance; D002540:Cerebral Cortex / Q000502:physiology*; D005260:Female; D006801:Humans; D015225:Magnetoencephalography / Q000379:methods; D008297:Male; D013017:Sound Localization / Q000502:physiology*; D013067:Speech Perception / Q000502:physiology*