HyperTTS: Parameter Efficient Adaptation in Text to Speech using Hypernetworks
Yingting Li, Rishabh Bhardwaj, Ambuj Mehrish, Bo Cheng, Soujanya Poria
TL;DR
HyperTTS introduces a parameter-efficient approach for adapting a multi-speaker TTS backbone to new speakers by conditioning adapters on speaker representations via a small hypernetwork. The hypernetwork dynamically generates adapter weights, expanding the effective parameter space while keeping the backbone frozen, achieving near-fine-tuning performance with less than 1% of backbone parameters added. Across LibriTTS and VCTK, HyperTTS surpasses static AdapterTTS and approaches full fine-tuning accuracy, with subjective MOS gains and strong speaker similarity, demonstrating practicality for scalable, domain-generic multi-speaker TTS. The work highlights dynamic, per-speaker adaptation as a promising direction, while noting training challenges and potential enhancements such as alternative normalization strategies and future exploration of LoRA-based variants.
Abstract
Neural speech synthesis, or text-to-speech (TTS), aims to transform a signal from the text domain to the speech domain. While developing TTS architectures that train and test on the same set of speakers has seen significant improvements, out-of-domain speaker performance still faces enormous limitations. Domain adaptation on a new set of speakers can be achieved by fine-tuning the whole model for each new domain, thus making it parameter-inefficient. This problem can be solved by Adapters that provide a parameter-efficient alternative to domain adaptation. Although famous in NLP, speech synthesis has not seen much improvement from Adapters. In this work, we present HyperTTS, which comprises a small learnable network, "hypernetwork", that generates parameters of the Adapter blocks, allowing us to condition Adapters on speaker representations and making them dynamic. Extensive evaluations of two domain adaptation settings demonstrate its effectiveness in achieving state-of-the-art performance in the parameter-efficient regime. We also compare different variants of HyperTTS, comparing them with baselines in different studies. Promising results on the dynamic adaptation of adapter parameters using hypernetworks open up new avenues for domain-generic multi-speaker TTS systems. The audio samples and code are available at https://github.com/declare-lab/HyperTTS.
