Improved noise removal method enhances animal sound recordings
2-Dimensional spectral gating for denoising bioacoustics recordings
Sound
Summary
Bioacoustics recordings often have a lot of background noise that makes it hard to hear animal sounds clearly. The authors improved an existing noise-reduction technique by taking advantage of how animal sounds spread across multiple frequencies. Their improved method works better for recordings of birds and marine mammals, making sounds clearer without slowing down the processing speed. This can help scientists study animals more accurately in noisy environments.
What this means in practice
- •For wildlife monitoring teams: Clean noisy animal audio recordings to improve species identification and communication studies in natural environments.
- •For audio engineers for underwater research: Enhance marine mammal audio recordings by reducing waterborne background noise while preserving vocalization details for analysis.
Authors
Julien Boussard, Mélisande Teng, Sulagna Saha, Mario Gallego-Abenza
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.