The perception of frequency modulated sounds in tone and non-tone language speakers: An electroencephalography study

Abstract

Speakers of tone languages acquire expertise in discriminating and identifying frequency modulated auditory signals [Chandrasekaran et al., Brain Res., 1128, 148–156 (2007); Kaan et al., Brain Res. 1148, 113–122 (2007)], as their native language utilizes such acoustic properties to cue lexical differences. How this expertise influences auditory neurophysiological responses to non-speech stimuli, however, remains poorly understood. We tested adult tone and non-tone language speakers in their automatic brain processing of non-speech frequency modulated (FM) tone chirps. Participants were presented with a series of FM tones in a many-to-one oddball mismatch negativity [MMN; Naatanen and Winkler, Psychol. Bull. 125, 826–856 (1999)] paradigm that varied in whether the modulation was concave or convex in nature and whether the difference between the tone chirp onset and offset frequencies was relatively large or small. The results revealed that the tone group produced a larger MMN than the non-tone group. Moreover, tone language participants produced significantly larger negative deflections in the event-related potential than the non-tone participants in response to both deviant types across a large post-stimulus time-window. Consequently, tone language speakers’ expertise in processing frequency cues impacts their neurophysiological responses to non-linguistic stimuli that vary along similar acoustic properties to linguistic stimuli.