A Unified Phonological Representation of South Asian Languages for Multilingual Text-to-Speech

We present a multilingual phoneme inventory and inclusion mappings from the native inventories of several major South Asian languages for multilingual parametric text-to-speech synthesis (TTS). Our goal is to reduce the need for training data when building new TTS voices by leveraging available data for similar languages within a common feature design. For West Bengali, Gujarati, Kannada, Malayalam, Marathi, Tamil, Tel-ugu, and Urdu we compare TTS voices trained only on monolingual data with voices trained on multilingual data from 12 languages. In subjective evaluations multilingually trained voices outperform (or in a few cases are statistically tied with) the corresponding monolingual voices. The multilingual setup can further be used to synthesize speech for languages not seen in the training data; preliminary evaluations lean towards good. Our results indicate that pooling data from different languages in a single acoustic model can be beneficial, opening up new uses and research questions.