Variation in the production of nasal coarticulation by speaker age and speech style.

This study investigates apparent-time variation in the production of anticipatory nasal coarticulation in California English. Productions of consonant-vowel-nasal words in clear vs casual speech by 58 speakers aged 18-58 (grouped into three generations) were analyzed for degree of coarticulatory vowel nasality. Results reveal an interaction between age and style: the two younger speaker groups produce greater coarticulation (measured as A1-P0) in clear speech, whereas older speakers produce less variable coarticulation across styles. Yet, duration lengthening in clear speech is stable across ages. Thus, age- and style-conditioned changes in produced coarticulation interact as part of change in coarticulation grammars over time.