Study on the human ability to aurally discriminate between target echoes and environmental clutter in recordings of incoherent broadband sonar

Abstract

Unacceptably high false-alarm rates due to the inability to discriminate between target echoes and environmental clutter are an issue for existing low-frequency active sonar systems operating in coastal environments. A research project at Defence R&D Canada—Atlantic is investigating the potential use of aural cues to tackle this challenge. One aspect of the project is to evaluate the human ability to aurally discriminate between target echoes and environmental clutter. The design and preliminary results from the study are presented here. Human subjects are presented with a series of sounds containing target echoes and clutter obtained from recordings of an incoherent broadband sonar experiment. The quantitative data collected in the study are the subjects’ decisions as to whether the echo heard was a target echo or clutter and their level of confidence associated with the decisions. Receiver-operating characteristic (ROC) analysis is used to produce a statistical model of the subjects’ performance. The study also includes a questionnaire: answers may prove useful in supporting the quantitative results and in providing a better understanding of the cues and decision techniques used by the subjects.