pycnet-audio: A Python package to support bioacoustics data processing

Abstract: Passive acoustic monitoring is an emerging approach in wildlife research that leverages recent improvements in purpose-made automated recording units (ARUs). The general approach is to deploy ARUs in the field to record on a programmed schedule for extended periods (weeks or months), after which the audio data are retrieved. These data must then be processed, typically either by measuring or analyzing characteristics of the audio itself (e.g. calculating acoustic indices), or by searching for some signal of interest within the recordings, e.g. vocalizations or other sounds produced by some target species, anthropogenic or environmental noise, etc. In the latter case, some method is required to locate the signal(s) of interest within the audio. While very small datasets can simply be searched manually, even modest projects can produce audio datasets on the order of 105 hours of recordings, making manual review impractical and necessitating some form of automated detection. pycnet-audio (Ruff 2024) is intended to provide a practical processing workflow for acoustic data, built around the PNW-Cnet model, which was initially developed by the U.S. Forest Service to support population monitoring of northern spotted owls (Strix occidentalis caurina) and other forest owls (Lesmeister and Jenkins 2022; Ruff et al. 2020). PNW-Cnet has been expanded to detect vocalizations of ca. 80 forest wildlife species and numerous forms of anthropogenic and environmental noise (Ruff et al. 2021, 2023).