The development of the perception of cues to the [m]-[n] distinction in CV syllables

The contribution of the nasal murmur and vocalic formant transition to the perception of the [m]-[n] distinction by adult listeners was investigated for speakers of different ages. Children, aged 3, 5, and 7, and an adult female and male produced consonant-vowel (CV) syllables consisting of either [m] or [n] and followed by [i ae u a]. Three productions of each syllable were computer edited into the following segments: (1) full murmur; (2) 50-ms murmur preceding release; (3) 25-ms murmur preceding release; (4) 25-ms murmur preceding release +25-ms transition following release; (5) 25-ms transition following release; (6) 50-ms transition following release; and (7) full transition+vowel. The results indicate that both the murmur and transition provide cues to place of articulation, but that the latter property is more prominent in perception than the former across speaker age. The salience of the murmur and vocalic transition cues was greater for adults than children indicating a developmental progression of the encoding of gestures associated with these properties. Although the simultaneous presence of murmur and vocalic transition cues surrounding the point of spectral discontinuity improved perception of place of articulation across speakers, there was evidence of a developmental progression of this property also. For speakers of all ages, as segment duration decreased, consistent decrements in identification of place of articulation occurred only for transition stimuli. The murmur+transition was the most salient cue supporting the importance of spectral discontinuities and/or relational properties in production and perception particularly in the acquisition of sound features.