A New Approach to Accent Recognition and Conversion for Mandarin Chinese

Two new approaches to accent classification and conversion are presented and explored, respectively. The first topic is Chinese accent classification/recognition. The second topic is the use of encoder-decoder models for end-to-end Chinese accent conversion, where the classifier in the first topic is used for the training of the accent converter encoder-decoder model. Experiments using different features and model are performed for accent recognition. These features include MFCCs and spectrograms. The classifier models were TDNN and 1D-CNN. On the MAGICDATA dataset with 5 classes of accents, the TDNN classifier trained on MFCC features achieved a test accuracy of 54% and a test F1 score of 0.54 while the 1D-CNN classifier trained on spectrograms achieve a test accuracy of 62% and a test F1 score of 0.62. A prototype of an end-to-end accent converter model is also presented. The converter model comprises of an encoder and a decoder. The encoder model converts an accented input into an accent-neutral form. The decoder model converts an accent-neutral form to an accented form with the specified accent assigned by the input accent label. The converter prototype preserves the tone and foregoes the details in the output audio. An encoder-decoder structure demonstrates the potential of being an effective accent converter. A proposal for future improvements is also presented to address the issue of lost details in the decoder output.