Evaluation on Binaural Technology in Hydro-Acoustic Surveillance Systems

The aim of the project was to evaluate the utilization potential of binaural technology in water listening systems. The project was carried out in the Acoustics Laboratory of the Helsinki University of Technology. A literature review was written and a large experimental listening test was carried out. There were 25 persons in the test and part of them were professional listeners in the Navy. The material in the listening test was authentic recordings from hydrophones, sine signals, and speech. The sounds were listened to by headphones and by loudspeakers. The test signals were prepared to an 8-channel loudspeaker system and the same soundscape was auralized to the headphones. Also, adding reverberation to the auralized signals to improve spatial quality was studied. An extensive statistical analysis was carried out and the most significant dependent variables were found to be errors in estimating the number and direction of targets. There were a few front-back errors, but they appeared mainly in loudspeaker reproduction. Finding the targets was facilitated statistically significantly if the number of channels was increased from 2 to 8. The results show the advantages of binaural technology in water listening systems.