Acoustic-Phonetic Approach toward Understanding Neural Processes and Speech Perception

This review paper describes an “acoustic-phonetic” experimental approach aimed at understanding normal and abnormal speech perception processes from both a behavioral and an electrophysiologic perspective. First, we consider the relevant acoustic characteristics of speech and identify a set of acoustic-phonetic classes that represent the parameters most important for making an acoustic signal sound like speech. Second, we review what is known about the neurophysiologic representation of acoustic-phonetic speech parameters in animal and human subjects. Third, we describe how an acoustic-phonetic approach has been useful in understanding the biologic basis of some auditory learning problems in children and in characterizing the behavioral and neurophysiologic changes resulting from speech-sound training. Finally, we discuss these findings and how they may expand the diagnostic and rehabilitative repertoire of practicing audiologists. Abbreviations: F0 = fundamental frequency; F1, F2, etc. = first formant, second formant, etc; fMRI = functional magnetic resonance imaging; JND = just noticeable difference; MMN = mismatch negativity