Before revision:  The model predicts pitch contours during inference , and generates speech that could be further controlled with predicted contours. FastPitch can thus change the perceived emotional state of the speaker or put emphasis on certain lexical units. We find that uniformly increasing or decreasing the pitch with FastPitch generates speech that resembles the voluntary modulation of voice.
After revision:  The model predicts pitch contours during inference . By altering these predictions, the generated speech can be more expressive, better match the semantic of the utterance, and in the end more engaging to the listener. Uniformly increasing or decreasing the pitch with FastPitch generates speech that resembles the voluntary modulation of voice.