Evaluating the effect of normalizing informal text on TTS output

Abbreviations in informal text, and research efforts to expand them to the standard English words from which they were derived, have become increasingly common. These methods are almost solely evaluated using the final word error rate (WER) after normalization; however, this metric may not be reasonable for a text-to-speech (TTS) system where words may be pronounced correctly despite being misspelled. This paper shows that normalization of informal text improves the output of TTS not only in terms of WER but also in terms of phoneme error rate (PER) and human perceptual experiments.