Effects of phonetic reduction and regional variation on lexical access

This study investigates the impact of acoustic variability on speech processing using a cross-modal priming experiment. Participants heard an audio prime consisting of a single lexical item followed by a printed word on the computer screen and were asked to indicate whether or not the word they heard was the same as the word on the screen. Auditory primes were balanced for linguistic factors that contribute to phonetic reduction, including lexical neighborhood density and whether the token was the first or second mention of the word in the larger context from which it was extracted. Primes were also balanced for social factors which contribute to phonetic variation, including regional dialect. To analyze the effect of these factors on speech processing, reaction times to matching prime-target pairs were analyzed. The results show that reaction times for Midland listeners were significantly faster following Midland primes than Northern primes, suggesting a native dialect benefit. However, the effect of dialect was smaller for words with a lower neighborhood density and for second mention primes relative to first mention primes. Together, these results suggest that dialect variation may have a smaller impact on speech processing in contexts that favor phonetic reduction.