Individual differences in the production of nasal coarticulation and perceptual compensation

- Perceptual evaluation of oral, nasal, and hypernasal vowels in C_C, C_N and N_N words.
- Listeners' produced coarticulatory proportion measured.
- Listeners' nasal vowel discrimination correlates with produced coarticulation.
- Greater produced coarticulation predicts veridical phonetic discrimination.
- Produced coarticulation did not correlate with vowel nasality ratings.

The current study investigates correlations between individual differences in the production of nasal coarticulation and patterns of perceptual compensation in American English. A production study (Experiment 1) assessed participants' nasal coarticulation repertoires by eliciting productions of CVC, CVN and NVN words. Stimuli for two perception tasks were created by cross-splicing oral vowels (from C_C words), nasal vowels (from C_N words), and hypernasal vowels (from N_N words) into C_C, C_N, and N_N consonant contexts. Stimuli pairs were presented to listeners in a paired discrimination task (Experiment 2), where similarity of vowels was assessed, and a nasality ratings task (Experiment 3), where relative nasalization of vowels was judged. In the discrimination task, individual differences in produced nasal coarticulation predicted patterns of veridical acoustic perception. Individuals who produce less extensive anticipatory nasal coarticulation exhibit more veridical acoustic perception (indicating less compensation for coarticulation) than individuals who produce greater coarticulatory nasality. However, in the ratings task, listeners' produced nasal coarticulation did not predict perceptual patterns. Rather, more veridical perceptual response patterns were observed across participants in context-inappropriate coarticulatory conditions, i.e., for hypernasal vowels in C_N contexts (e.g. bẽ̃n) and nasal vowels in N_N contexts (e.g. mẽn). The results of this study suggest a complex and multifaceted relationship between representations used to produce and perceive speech.