Production and perception of n∼l alternation in Sichuan Mandarin

This study investigates the n∼l alternation in Sichuan Mandarin (SM), a Southwestern Mandarin variety showing signs of neutralization word-initially. Similar mergers have been reported in Cantonese and Fuzhou Min (To et al., 2015; Cheng et al., 2023), suggesting a broader phonological trend. Drawing on Labov’s (1994) framework of near-merger, we examine whether SM speakers maintain acoustic distinctions in production despite reduced perceptual sensitivity. Our design includes a picture-naming task, paired with an AX discrimination and forced-choice identification tasks, allowing us to explore the perception-production interface in a potential phonological merger. Perceptual stimuli form a 7-step /nV/–/lV/ continuum for two vowel contexts (/i/ and /a/), created via spectral interpolation of natural tokens and controlled for duration, intensity, and pitch. Following prior work (Zhang, 2007; Cheng et al., 2023), we predict production will be conditioned by vowel height and perception biased toward l. Social variables—age, gender, and Standard Mandarin exposure (Yao & Chang, 2016)—are also examined. Data collection is ongoing with ∼36 native SM speakers in Chengdu and Deyang. Preliminary results indicate a perceptual shift toward l, consistent with a merger-in-progress. This work contributes to our understanding of phonological contrast shift, sound change, and sociophonetic variation in Sino-Tibetan dialects.