Dialectal and Individual Influences on Nasality Perception: Evidence From Midland and Inland North

This study examined how dialectal background and individual production patterns influence nasality perception in American English, focusing on Midland and Inland North listeners. Forty-one adults from the two dialect regions completed nasometric testing to index oral–nasal balance characteristics (nasalance). Nasality perception was assessed using direct magnitude estimation (DME) of phrase-level synthetic stimuli, representing a continuum of synthesized velopharyngeal (VP) port sizes (0–0.20 cm², in 0.04 cm² steps). Results showed no significant between-dialect differences in nasalance. In contrast, DME ratings increased systematically with synthesized VP port size and differed by dialect, with Inland North listeners assigning higher ratings than Midland listeners, particularly at larger synthesized VP port sizes, yielding a significant dialect-by-synthesized VP port size interaction. Correlation analyses further examined production-perception relationships and revealed a significant negative association between nasalance and DME ratings for the 0.08 cm² stimulus among Midland listeners, whereas no such association emerged among Inland North listeners. These findings indicate that perceptual judgments of nasality may vary even when production measures appear comparable. One possible explanation is that dialect contact may reduce production differences while perceptual representations remain relatively stable. The production-perception relationship observed exclusively for the 0.08 cm² stimulus among Midland listeners further suggests that such links may be most evident when external stimulus contrast is minimal and listeners’ production and perceptual norms remain aligned. More broadly, these findings support the view that nasality perception is shaped by experience-based listener factors, consistent with exemplar and normalization accounts of speech perception.