Human echolocation using click trains and continuous noise

Document type: Conference Papers
Peer reviewed: Yes
Full text:
Author(s): Bo Schenkman, Mats E. Nilsson, Nedelko Grbic
Title: Human echolocation using click trains and continuous noise
Conference name: Annual Meeting of the International Society for Psychophysics
Year: 2011
Publisher: International Society for Psychophysics
City: Herzliya, Israel
Organization: Blekinge Institute of Technology
Department: School of Engineering - Dept. of Electrical Engineering, School of Management (Sektionen för ingenjörsvetenskap - Avd. för elektroteknik, Sektionen för management)
School of Engineering S-371 79 Karlskrona, School of Management S- 371 79 Karlskrona
+46 455 38 50 00;
Language: English
Abstract: Blind people may detect objects from the information in reflected sounds, echolocation. Detection as a function of the number of clicks compared to a continuous noise was tested by presenting clicks of 5 ms with rates from 1 to 64 clicks during a 500 ms period and a 500-ms continuous white noise. The sounds were recorded in an ordinary room through an artificial binaural head. The reflecting object was an aluminum disk, diameter 0.5 m, at distances of 1 and 1.5 m. These sounds were later presented to 3 blind and 16 sighted participants in a laboratory using a 2AFC methodology. The task was to detect which of the two sounds that contained a reflecting object. Feedback was provided. The blind participants had a higher detection than the sighted, but there were also differences among the blind. These results are put in relation to physical features such as the autocorrelation function and spectral variations.