Detection of nasals as a function of duration

Abstract

Previous studies have shown distributional restrictions on nasal stops. Specifically, in many languages nasal stops are followed only by a nasal vowel, which is also usually comparatively longer to contrast with the vocalic context adjacent to oral stops. This was observed as a phonological constraint in Taiwanese (Southern Min), but not in French. This study tests the discriminability of Taiwanese and French listeners on plain and nasal stops. The speech stimuli were cross spliced nasal versus oral stops and oral versus nasal vowels: CV, NV, CṼ, NṼ. The vowel duration was also manipulated to see if the perceived nasality will be enhanced when the vowels are longer, and further affect the intelligibility for the consonants before them. Preliminary results indicated that the Taiwanese listeners predicted wrong consonantal categories when the nasality of the following vowel is not agree with the preceding consonant. French listeners showed no such effect. The durational effect shows the opposite: Taiwanese listeners perceived the same stop category regardless of the duration of the following vowel, whereas French listeners are biased toward the nasal category when the following vowel is longer.