Synthesis after a couple PINTs: Investigating the role of pause-internal phonetic particles in speech synthesis and perception

Pause-internal phonetic particles (PINTs), such as breath noises, tongue clicks and hesitations, play an important role in speech perception but are rarely modeled in speech synthesis. We developed two text-to-speech (TTS) systems: one with and one without PINTs labels in the training data. Both models produced fewer PINTs and had a lower total PINTs duration than natural speech. The labeled model generated more PINTs and longer total PINTs durations than the model without labels. In a listening experiment based on the labeled model we evaluated the influence of various PINTs combinations on the perception of speaker certainty. We tested a condition without PINTs material and three conditions that included PINTs. The condition without PINTs was perceived as significantly more certain than the PINTs conditions, suggesting that we can modify how certain TTS is perceived by including PINTs.