A Study of Temporal Features and FrequencyCharacteristics in American English Foreign

In this paper, a detailed acoustic feature study of foreign accent using temporal features, intonation patterns, and frequency characteristics in American English is performed. Using a database which consists of words uttered in isolation, temporal features such as voice onset time, word-nal stop closure duration, and characteristics of duration are investigated. Accent diierences for native-produced versus Mandarin, German, and Turkish accented English utterances are analyzed. Of the dimensions considered the most important is found to be word-nal stop closure duration. Mandarin accented English utterances show signiicant diierences in terms of this feature when compared to native speaker utterances. In addition, the intonation characteristics across a set of foreign accents in American English is investigated. It is shown that Mandarin speaker utterances possess a larger negative continuative intonation slope than native speaker utterances, and German speaker utterances had a more positive intonation slope when compared to native speaker utterances. Finally, a detailed frequency analysis of foreign accented speech is conducted. It is shown that the mid-frequency range (1500-2500 Hz) is the most sensitive frequency band to non-native speaker pronunciation variations. Based on this knowledge a new frequency scale for the calculation of cepstrum coeecients is formulated which is shown to outperform the Mel-scale in terms of its ability to classify accent automatically among four accent classes. PACS Code 43.72Lw Language Acquisition z Permission is hereby granted to publish this abstract separately.