ISCA Archive SSW 2021
ISCA Archive SSW 2021

Mind your p’s and k’s -- Comparing obstruents across TTS voices of the Blizzard Challenge 2013

Ayushi Pandey, Sébastien Le Maguer, Julie Berndsen, Naomi Harte

Obstruent consonants have been investigated in speech quality assessment studies of natural speech, where enhancing their perception has improved overall speech quality. This paper presents a comparative analysis of acoustic-phonetic features of obstruent consonants in synthetic speech. Features for obstruent consonants are identified where TTS systems differ significantly from a natural human voice, as a function of quality. The synthetic speech voices from the Blizzard Challenge of 2013 are used for this investigation. TTS systems were first assigned groups based on their MOS rating (quality) and shared TTS technique (family). Then, acoustic-phonetic features characteristic of contrastive properties in obstruents, were extracted from all systems. While quality differences between low-rated systems and high-rated systems were observed in a large number of features, we report those where statistically significant differences (p-val < 0.001) were observed between the systems. Where quality effects were not found, we investigated whether systems of the same family exhibit similar behaviour. Finally, individual systems within a group were examined for their differing influence on the acoustic-phonetic feature set of obstruents. Here, we found that HMM systems with similar MOS ratings do not differ in their acoustic realization of obstruents, while Unit Selection systems showed stronger individual system variability. A comparative analysis of obstruent consonants across TTS systems applies techniques from the domain of corpusphonetics to the task of speech synthesis evaluation. Identifying phonologically relevant acoustic features, may indicate the underlying articulatory process compromised in those systems, that correlates with the distorted acoustics.

doi: 10.21437/SSW.2021-29

Cite as: Pandey, A., Maguer, S.L., Berndsen, J., Harte, N. (2021) Mind your p’s and k’s -- Comparing obstruents across TTS voices of the Blizzard Challenge 2013. Proc. 11th ISCA Speech Synthesis Workshop (SSW 11), 166-171, doi: 10.21437/SSW.2021-29

  author={Ayushi Pandey and Sébastien Le Maguer and Julie Berndsen and Naomi Harte},
  title={{Mind your p’s and k’s -- Comparing obstruents across TTS voices of the Blizzard Challenge 2013}},
  booktitle={Proc. 11th ISCA Speech Synthesis Workshop (SSW 11)},