Human Ability to Judge Relative Size and Lateral Position of a Sound Reflecting Board Using Click Signals: Influence of Source Position and Click Properties

In human echolocation, acoustic signals provide information enabling people to perceive the physical environment. Little is known about the relation between properties of click signals used for echolocation purposes and the effect of source position on the resulting echolocation performance. In this work, echolocation performance is studied for two different echolocation tests: board size identification and board lateralization. The used artificial source is placed in front of the mouth and in front of the chest. Three different synthesized test signals are used: two narrow band signals and one broadband click signal. Impulse responses were recorded in an anechoic room for each individual participant, and listening tests were carried out afterwards by playing post-processed individualized signals using headphones. Results show better performance with the sound source at the chest position in both experiments, with the difference in performance most prominent in the board size identification test. In the board lateralization test, the broadband click results in eminent better performance over narrow band click signals. This suggest that broadband and chest positioned signals seem favorable over narrow band and mouth positioned signals.