How to Make Text-to-Speech System Pronounce "Voldemort": an Experimental Approach of Foreign Word Phonemization in Vietnamese

Generating foreign words is one of the hardest tasks for any speech synthesis systems. This work deal with this problem in the case of Vietnamese, a low-resourced language, following an experimental approach. Base on a deep analysis of the usage of foreign words in Vietnamese, various types of pronunciation dictionaries for foreign words was proposed including rule-based phonemization, word-to-syllables mapping, and cross-lingual phone-to-phone mapping. These dictionaries were then used to train different types of grapheme-to-phoneme (G2P) converters. The perceptual evaluation of the Vietnamese synthesized speech confirms that the output of the proposed method can compare favorably with the pronunciation by the human on the unseen foreign words.