| The effects of linguistic experience on the perceptual classification of phonological dialect variation were investigated in a series of behavioral experiments with naive listeners. A new digital speech corpus was collected which contains audio recordings of five male and five female talkers from each of six dialect regions in the United States (New England, Mid-Atlantic, North, Midland, South, and West). The speech materials recorded from each talker included isolated words, sentences, passages of connected text, and conversational speech. Acoustic analyses of the vowel systems of the talkers confirmed significant phonological variation due to regional dialect. Perceptual classification of dialect variation was assessed using sentence-length utterances from the new corpus with a six-alternative forced-choice categorization task and a free classification task. The independent variables examined in this study reflected the residential history of the listeners. In particular, two levels of the variables 'geographic mobility' and 'geographic location' were crossed to produce four different listener groups. For the mobility variable, listeners were either mobile (lived in more than one dialect region) or non-mobile (lived in only one dialect region). For the location variable, listeners came from either the Northern or the Midland dialect region of the United States. While residential history did not produce differences in overall accuracy in the forced-choice categorization task or classification strategy in the free classification task, residential history was found to affect the perceptual similarity of the six regional varieties examined. Clustering and multidimensional scaling analyses revealed that both geographic mobility and location help to shape the perceived similarity between geographically local dialects. In particular, the Northern listeners perceived a greater similarity between Northern and Midland talkers than the Midland listeners, while the Midland listeners perceived a greater similarity between the Midland and Southern talkers than the Northern listeners. In addition, the perceptual similarity spaces of the mobile listeners were less affected by geographic location than the similarity spaces of the non-mobile listeners. The perceptual classification results from this study contribute to the growing literature on the effects of linguistic experience on the perception of dialect variation by naive listeners. |
