2-Dimensional spectral gating for denoising bioacoustics recordings

2026-09-29

AI Summary

This study addresses the challenges of severe environmental noise interference in bioacoustic recordings and the limited generalizability of existing denoising methods by proposing an enhanced noise reduction technique based on two-dimensional spectral gating. Moving beyond conventional single-frequency thresholding, the proposed method introduces a cross-frequency structural awareness mechanism that integrates multi-channel correlation analysis with adaptive noise threshold estimation. By leveraging the multi-frequency structural characteristics of animal vocalizations, it optimizes the Noisereduce algorithm. Experimental results demonstrate that this approach significantly improves denoising robustness in complex underwater and aerial acoustic environments for both avian and marine mammal recordings. Furthermore, it achieves high real-time performance and strong generalization capability without introducing additional computational overhead during preprocessing.

Abstract

Isolating vocalizations from noise in bioacoustics recordings is a prerequisite to many ecological analyses, including species identification, animal communication understanding, and individual or population-level variability studies. However, when recordings are acquired in open environments, vocalizations, noise, or signal-to-noise ratio can vary widely across individuals, species, environment, and recording conditions, making it hard to develop robust and generalizable methods for ecological analyses. To account for these challenges, noise reduction techniques are used to remove noise before downstream analyses. Popular methods such as Noisereduce rely on spectral gating, which estimates a noise threshold for each frequency channel. We propose a further improvement to Noisereduce, leveraging the fact that most animal sounds have structure across multiple frequencies. We apply our method on bird and marine mammals recordings and show that our extension of Noisereduce leads to improved denoising in both above and under water acoustic recordings, without impacting speed of preprocessing.

Problem

• bioacoustics
• denoising
• spectral gating
• noise reduction
• ecological analysis

Innovation

• Spectral gating
• Bioacoustics denoising
• Noisereduce
• Two-dimensional processing
• Noise reduction