GOMPSNR: Reflourish the Signal-to-Noise Ratio Metric for Audio Generation Tasks
Lingling Dai, Andong Li, Cheng Chi, Yifan Liang, Xiaodong Li, Chengshi Zheng
TL;DR
This work tackles the misalignment between SNR-based metrics and human perception in audio generation. It introduces GOMPSNR, a phase-aware metric that replaces the traditional instantaneous phase with omnidirectional phase derivatives $\nabla_i\theta$ and includes a corrected correlation term to improve stability and perceptual relevance. It further proposes phase-oriented losses, including magnitude-guided refinement (WOP) and joint magnitude–phase losses (ORI, CORI), demonstrating that a carefully chosen combination yields substantial gains across multiple vocoders and neural audio codecs. Across LJSpeech, LibriTTS, and auxiliary codec evaluations, GOMPSNR shows stronger correlation with perceptual metrics and the proposed losses yield clear improvements in objective quality and intelligibility.
Abstract
In the field of audio generation, signal-to-noise ratio (SNR) has long served as an objective metric for evaluating audio quality. Nevertheless, recent studies have shown that SNR and its variants are not always highly correlated with human perception, prompting us to raise the questions: Why does SNR fail in measuring audio quality? And how to improve its reliability as an objective metric? In this paper, we identify the inadequate measurement of phase distance as a pivotal factor and propose to reformulate SNR with specially designed phase-distance terms, yielding an improved metric named GOMPSNR. We further extend the newly proposed formulation to derive two novel categories of loss function, corresponding to magnitude-guided phase refinement and joint magnitude-phase optimization, respectively. Besides, extensive experiments are conducted for an optimal combination of different loss functions. Experimental results on advanced neural vocoders demonstrate that our proposed GOMPSNR exhibits more reliable error measurement than SNR. Meanwhile, our proposed loss functions yield substantial improvements in model performance, and our wellchosen combination of different loss functions further optimizes the overall model capability.
