Sound anomalies of Cornell Swift recorders affect ecoacoustic studies, and a workaround solution

Abstract The Swift Terrestrial Passive Acoustic Recording Unit from Cornell Lab of Ornithology, running firmware v. STM32 0.18.6.3, produced an initial 4‐sec sound anomaly in each (wave file) recording, created by the power‐saving features unit as it switches standby to record mode. had a statistically significant impact on several soundscape indices calculated recordings. Here, case study identifying and solving this problem, I dissected nature analyzed variable effects has ecoacoustic indices. used sample 150, 10‐min files, recorded during my ecoacoustics central boreal Alaska 2019 (June‐August) 2020 (April‐September), stratified landscape conditions types sounds representing anthrophony, biophony, geophony conditions. significantly biased calculations 7 13 all these There is no simple correction factor that can be applied index values account for anomaly. suggest workarounds, notably automate procedure delete specified segment file eliminate prior analysis, general watch correct such anomalies when using Autonomous Units recordings analyses.