The effect of context duration on Mandarin listeners' tone normalization.

Tone normalization has been observed in Mandarin listeners, who contrastively adjust tone recognition using context pitch cues. This study tested the effect of context duration on Mandarin tone normalization. The target tones varied from Tone 1 (high-flat) to Tone 2 (mid-rising). The preceding phrase was modified to have different durations with 160- or 200-Hz mean fundamental frequencies (F0s). The results showed that the high-F0 context elicited significantly more Tone-2 responses than the low-F0 context, even when the contexts were 125 ms. The contrastive context effect saturated with the 250-ms contexts, indicating a 250-ms critical context duration for robust tone normalization.