Individual and group differences in the perception of regional dialect variation in a second language

In this dissertation, four studies investigated the perception of regional dialect variability in a second language (L2). The first study examined the perception of regional dialects in American English by non-native Korean listeners. Overall, the non-native listeners had more difficulty recognizing speech produced by talkers from different U.S. dialect regions in a multi-dialect sentence recognition task and categorizing talkers by region of origin in a forced-choice regional dialect categorization task compared to native listeners. However, their perception of the dialects was greatly influenced by the task demands, the specific regional varieties in the tasks, and their language background and experience.;Sources of individual differences attested in the first study were also explored. The second study investigated the relation between L2 phonological and lexical knowledge and performance on the multi-dialect sentence recognition task and the forced-choice dialect categorization task. A third study examined the relation between several neurocognitive abilities and performance on the two tasks. Results of the two studies showed that L2 phonological and lexical knowledge was related to scores on the multi-dialect sentence recognition task, while several neurocognitive abilities were related to scores on both perception tasks.;The final study investigated the effects of regional dialect categorization training on native and non-native listeners' perception of regional dialects of American English. Listeners who received the training improved in their ability to categorize regional dialects. Additionally, the listeners' language background did not influence the effectiveness of the training. However, listeners' performance on a set of transfer perception tasks showed no evidence of any transfer effects from the training.;Taken together, the four studies establish basics concerning the perception of regional dialect variation in L2 acquirers, provide indications about sources of individual differences in L2 speech perception, and probe the relation between the processing of linguistic and indexical information in speech.