Neurophysiologic processing of Ling-6 speech sounds

The Ling-6 speech sounds have been widely in the fields of audiology and speech-language pathology. However, there is little knowledge of the neurophysiologic processing of speech sounds at a cortical level, hence the need for this study. The aim of this study was to examine the neurophysiologic processing of Ling-6 sounds. Sixteen adults were recruited for the study. The stimuli included natural digitized speech stimuli of the Ling-6 phonemes: /a/, /i/, /u/, /s/, /ʃ/, /m/. Electroencephalography was recorded in a sound attenuated booth and a passive paradigm was used. The responses were processed, analyzed, and the brain responses specifically, amplitudes and latencies of P1, N1, and P2 responses were measured. Descriptive statistics and inferential statistics were performed, specifically, analysis of variance (ANOVA) was used. The N1 latencies were shorter for /s/, P2 latencies were longer for /ʃ/ relative to the other sonorants. In terms of amplitudes, /u/ had the lowest P1 amplitudes and /m/ had the highest amplitude. N1 amplitudes were significantly lesser (p < 0.05) for vowels relative to fricatives. Results from this research have clinical implications and allow for future research in electrophysiology toward aural rehabilitation.