Enhanced Prosody Modeling and Character Voice Controlling for Audiobook Speech Synthesis

Conventional speech synthesis techniques have made significant strides towards achieving human-like performance. However, the domain of audiobook speech synthesis still presents notable challenges. On one hand, the speech in audiobooks exhibits rich prosodic expressiveness, posing substantial difficulties in prosody modeling. On the other hand, the reader of audiobooks uses different voices to perform dialogues of different characters, which has been inadequately explored in existing speech synthesis methods. To address the first challenge, we integrate discourse-scale prosody modeling into the conventional autoencoder-based framework and introduce generative adversarial networks (GANs) for phoneme-level prosody code prediction. Regarding the second challenge, we further explore a character voice encoder based on the pretrained speaker verification model, integrating it into our proposed method. Experimental results validate that the proposed method enhances the prosodic expressiveness of synthesized audiobook speech. Moreover, it demonstrates the capacity to produce distinctive voices for different audiobook characters without compromising the naturalness of the synthesized speech.