Enhancing Noise Robustness for Neural Speech Codecs through Resource-Efficient Progressive Quantization Perturbation Simulation

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Zheng, Rui-Chen, Ai, Yang, Du, Hui-Peng, Dai, Li-Rong
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866912643937206272
author Zheng, Rui-Chen
Ai, Yang
Du, Hui-Peng
Dai, Li-Rong
author_facet Zheng, Rui-Chen
Ai, Yang
Du, Hui-Peng
Dai, Li-Rong
contents Noise robustness remains a critical challenge for deploying neural speech codecs in real-world acoustic scenarios where background noise is often inevitable. A key observation we make is that even slight input noise perturbations can cause unintended shifts in quantized codewords, thereby degrading the quality of reconstructed speech. Motivated by this finding, we propose a novel and resource-efficient training strategy to enhance the noise robustness of speech codecs by simulating such perturbations directly at the quantization level. Our approach introduces two core mechanisms: (1) a distance-weighted probabilistic top-K sampling strategy that replaces the conventional deterministic nearest-neighbor selection in residual vector quantization (RVQ); and (2) a progressive training scheme that introduces perturbations from the last to the first quantizer in a controlled manner. Crucially, our method is trained exclusively on clean speech, eliminating the need for any paired noisy-clean data. Experiments on two advanced neural speech codecs, Encodec and WavTokenizer, demonstrate that the proposed strategy substantially improves robustness under noisy conditions-for example, boosting UTMOS from 3.475 to 3.586 at 15 dB SNR on Encodec-while also enhancing coding quality for clean speech.
format Preprint
id arxiv_https___arxiv_org_abs_2509_19025
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Enhancing Noise Robustness for Neural Speech Codecs through Resource-Efficient Progressive Quantization Perturbation Simulation
Zheng, Rui-Chen
Ai, Yang
Du, Hui-Peng
Dai, Li-Rong
Audio and Speech Processing
Noise robustness remains a critical challenge for deploying neural speech codecs in real-world acoustic scenarios where background noise is often inevitable. A key observation we make is that even slight input noise perturbations can cause unintended shifts in quantized codewords, thereby degrading the quality of reconstructed speech. Motivated by this finding, we propose a novel and resource-efficient training strategy to enhance the noise robustness of speech codecs by simulating such perturbations directly at the quantization level. Our approach introduces two core mechanisms: (1) a distance-weighted probabilistic top-K sampling strategy that replaces the conventional deterministic nearest-neighbor selection in residual vector quantization (RVQ); and (2) a progressive training scheme that introduces perturbations from the last to the first quantizer in a controlled manner. Crucially, our method is trained exclusively on clean speech, eliminating the need for any paired noisy-clean data. Experiments on two advanced neural speech codecs, Encodec and WavTokenizer, demonstrate that the proposed strategy substantially improves robustness under noisy conditions-for example, boosting UTMOS from 3.475 to 3.586 at 15 dB SNR on Encodec-while also enhancing coding quality for clean speech.
title Enhancing Noise Robustness for Neural Speech Codecs through Resource-Efficient Progressive Quantization Perturbation Simulation
topic Audio and Speech Processing
url https://arxiv.org/abs/2509.19025