The role of experience in processing foreign-accented speech

The present study examines the perceptual accommodation of the bilabial stop-consonant voicing contrast (i.e., /b/ vs. /p/), in several English- and Spanish-accented contexts, by native Spanish listeners with different degrees of experience with accented speech. In a series of four experiments, we confronted three potential mechanisms for the perceptual accommodation of foreign-accented sounds. According to the first mechanism (phonetic relaxation), listeners accommodate foreign-accented sounds by relaxing the phonetic boundary between native speech sound categories. According to the second mechanism (phonetic calibration), listeners accommodate foreign-accented sounds by adjusting the location of native perceptual boundaries according to the phonetic realization of native categories in the foreign-accented speech context. Finally, according to the third mechanism (phonetic switching), foreign-accented speech sounds are accommodated by switching to a non-native system of phonetic representations that was previously developed through long-term experience with the speech norm of the foreign accent. Experimental results indicate that Spanish listeners did not relax the phonetic boundary between /b/ and /p/ in an English-accented Spanish context (Experiments 1 and 3). However, they accommodated English-accented Spanish voicing differently, depending on their degree of experience with the English-accented speech norm. When Spanish listeners had little or no experience with the English norm, they calibrated the location of the perceptual boundary between /b/ and /p/ according to the Spanish or English phonetic realization of these sounds in the speech context (Experiment 4). Alternatively, when they had a high degree of experience with English-accented speech, they accommodated English-accented Spanish /b/ and /p/ by using an English-like system of phonetic representations that was not predictable from the phonetic realization of /b/ and /p/ in the speech context (Experiments 1 and 2). These experimental results contribute to a better understanding of the role played by non-native experience in the perceptual accommodation of foreign-accents. In particular, they indicate that native listeners may rely on previous long-term experience with the native language of the foreign-accented speaker to efficiently accommodate foreign-accented speech variability in a different way to which they accommodate speech variability from different native-accented speakers