Categorical perception of lexical tones based on acoustic-electric stimulation

The effect of low-frequency acoustic input on the categorical perception of lexical tones was investigated with simulated electric-acoustic hearing. A synthesized T1-T2 (flat-rising) tone continuum of Mandarin monosyllables /i/ was used, and they were manipulated as five conditions: unprocessed, low-frequency acoustic-only, electric-only, electric-acoustic stimulation, and bimodal stimulation. Results showed the performance under electric-only condition was the significantly lowest, and the difference of other pairwise comparisons between conditions was quite small. These findings suggest that the low-frequency acoustic input can shape the categorical perception, and the combinations of acoustic and electric hearing within or across ears have no significant effect.