Under-resourced dialect identification in Ao using source information

This paper reports the findings of an automatic dialect identification (DID) task conducted on Ao speech data using source features. Considering that Ao is a tone language, in this study for DID, the gammatonegram of the linear prediction residual is proposed as a feature. As Ao is an under-resourced language, data augmentation was carried out to increase the size of the speech corpus. The results showed that data augmentation improved DID by 14%. A perception test conducted on Ao speakers showed better DID by the subjects when utterance duration was 3 s. Accordingly, automatic DID was conducted on utterances of various duration. A baseline DID system with the S_lms feature attained an average F1-score of 53.84% in a 3 s long utterance. Inclusion of source features, S_ilpr and _S, improved the F1-score to 60.69%. In a final system, with a combination of S_ilpr, _S, S_lms, and Mel frequency cepstral coefficient features, the F1-score increased to 61.46%.