An iterative kurtosis-based technique for the detection of nonstationary bioacoustic signals

A novel technique for the detection of nonstationary bioacoustic signals, such as explosive lung and bowel sounds, in clinical auscultative recordings is presented. The technique uses kurtosis (zero-lag fourth-order statistics) to form an iterative kurtosis-based detector (IKD). The IKD iteratively detects important peaks of the kurtosis, estimated within a sliding window along the signal under investigation, which indicate the presence of non-Gaussianity in the raw signal. The efficiency of the IKD has been illustrated by experimental results that demonstrate its ability to clearly detect bioacoustic signals of diagnostic interest in the presence of background signal with high amplitude.