Modular Synthesis of Disfluencies for Conversational Speech Systems

Betz, Simon and Wagner, Petra and Schlangen, David

It has been shown that dialogue systems benefit from incremental architectures to produce fast responses and to interact with the interlocutor in a more human-like way. The advantage of quick responses yields the disadvantage of running out of things to say for a while. In such occasions, humans tend to produce disfluencies as a listener-oriented strategy to signal the ongoing production process and to buy time for finalizing the turn. Introducing disfluency capabilities into a speech synthesis module of a dialogue system may therefore be a straightforward strategy towards conversational speech systems. Disfluencies are a very complex matter, they can take various chaining and nested forms in human communication. We do not attempt to equip our system with the full range of possible disfluent time-buying strategies found in human interaction. For a first perceptual evaluation of the most suitable synthetic disfluency strategy to be integrated into the dialogue system, we focus on three structural factors that are able to cover a wide range of attested disfluency patterns: lengthening, word cutoffs and pauses. This leads to several different configurations a disfluent sentence can take. Sentences from a spontaneous speech corpus were resynthesized in all possible configurations using Mary TTS. In order to identify euphone configurations, these stimuli were then presented to test subjects in a perception test.

In , 2015
  author = {Betz, Simon and Wagner, Petra and Schlangen, David},
  keyword = {Incrementality, Disfluencies, Speech Synthesis},
  location = {Eichstätt},
  pages = {128--134},
  title = {{Modular Synthesis of Disfluencies for Conversational Speech Systems}},
  year = {2015}