Vevo: Controllable Zero-Shot Voice Imitation with Self-Supervised Disentanglement

The imitation of voice, targeted on specific speech attributes such as timbre and speaking style, is crucial in speech generation. However, existing methods rely heavily on annotated data, and struggle with effectively disentangling timbre and style, leading to challenges in achieving controllable generation, especially in zero-shot scenarios. To address these issues, we propose Vevo, a versatile zeroshot voice imitation framework with controllable timbre and style. Vevo operates in two core stages: (1) Content-Style Modeling: Given either text or speech's content tokens as input, we utilize an autoregressive transformer to generate the content-style tokens, which is prompted by a style reference; (2) Acoustic Modeling: Given the content-style tokens as input, we employ a flow-matching transformer to produce acoustic representations, which is prompted by a timbre reference. To obtain the content and content-style tokens of speech, we design a fully self-supervised approach that progressively decouples the timbre, style, and linguistic content of speech. Specifically, we adopt VQ-VAE [1] as the tokenizer for the continuous hidden features of HuBERT [2]. We treat the vocabulary size of the VQ-VAE codebook as the information bottleneck, and adjust it carefully to obtain the disentangled speech representations. Solely self-supervised trained on 60K hours of audiobook speech data, without any fine-tuning on style-specific corpora, Vevo matches or surpasses existing methods in accent and emotion conversion tasks. Additionally, Vevo's effectiveness in zero-shot voice conversion and text-to-speech tasks further demonstrates its strong generalization and versatility. The imitation of voice has long been an important issue in the field of speech generation. This includes the imitation of speaker identity [3, 4], the imitation of speaking style such as accent [5, 6] or emotion [7], and a broader concept of voice cloning such as in zero-shot text-to-speech (TTS) task [8]. These techniques have a wide range of applications, including spoken language learning [5, 6, 9], voice anonymization [10], voice assistants [11, 12], and video dubbing [11, 12, 13]. To achieve targeted and controllable imitation over various speech attributes, many studies focuses on factorizing speech into multiple sub-spaces [14, 15, 16, 17]. In this work, we follow this idea and decompose speech into three key attributes: linguistic content (what to speak), style (how to speak), and timbre (who speaks).