A method for filtering bioacoustic transients by spectrogram image convolution

The method detects bowhead calls well, performing better than a matched filter and a hidden Markov model on the task, and weaknesses of the method are discussed.

Abstract

A method is presented for detecting bioacoustic transients. The desired transient-an animal call-is modeled as a sequence of frequency sweeps. Sweeps are detected by convolving a spectrogram of the signal with a kernel designed for the call of interest; convolution output is high when the call of interest is present and low other times. The method is tested on a set of bowhead whale (Balaena mysticetus) calls recorded in a noisy Arctic environment. The method detects bowhead calls well, performing better than a matched filter and a hidden Markov model on the task. Strengths and weaknesses of the method are discussed.>