Modern psychophysical models of auditory modulation processing suggest that concurrent auditory features with syllabic (∼5 Hz) and phonemic rates (∼20 Hz) are processed by different modulation filterbank elements, whereas features at similar modulation rates are processed together by a single element. The neurophysiology of concurrent modulation processing at speech-relevant rates is here investigated using magnetoencephalography. Results demonstrate expected neural responses to stimulus modulation frequencies; nonlinear interaction frequencies are also present, but, critically, only for nearby rates, analogous to "beating" in a cochlear filter. This provides direct physiological evidence for modulation filterbanks, allowing separate processing of concurrent syllabic and phonemic modulations.
ASJC Scopus subject areas
- Arts and Humanities (miscellaneous)
- Acoustics and Ultrasonics