title: Identification of the lateral position of a virtual object based on echoes by humans.
abstract: Echolocation offers a promising approach to improve the quality of life of people with blindness although little is known about the factors influencing object localisation using a 'searching' strategy. In this paper, we describe a series of experiments using sighted and blind human listeners and a 'virtual auditory space' technique to investigate the effects of the distance and orientation of a reflective object and the effect of stimulus bandwidth on ability to identify the right-versus-left position of the object, with bands of noise and durations from 10-400 ms. We found that performance reduced with increasing object distance. This was more rapid for object orientations where mirror-like reflection paths do not exist to both ears (i.e., most possible orientations); performance with these orientations was indistinguishable from chance at 1.8 m for even the best performing listeners in other conditions. Above-chance performance extended to larger distances when the echo was artificially presented in isolation, as might be achieved in practice by an assistive device. We also found that performance was primarily based on information above 2 kHz. Further research should extend these investigations to include other factors that are relevant to real-life echolocation.
authors.affiliation: Institute of Sound and Vibration Research, University of Southampton, Southampton, Hants SO17 1BJ, UK. d.rowan@southampton.ac.uk
authors.forename: Daniel
authors.initials: D
authors.lastname: Rowan
authors.forename: Timos
authors.initials: T
authors.lastname: Papadopoulos
authors.forename: David
authors.initials: D
authors.lastname: Edwards
authors.forename: Hannah
authors.initials: H
authors.lastname: Holmes
authors.forename: Anna
authors.initials: A
authors.lastname: Hollingdale
authors.forename: Leah
authors.initials: L
authors.lastname: Evans
authors.forename: Robert
authors.initials: R
authors.lastname: Allen
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001299:Audiometry; D001309:Auditory Threshold; D003463:Cues; D005260:Female; D006801:Humans; D008297:Male; D009038:Motion; D009949:Orientation; D017603:Signal Detection, Psychological; D013016:Sound; D013017:Sound Localization; D013018:Sound Spectrography; D013028:Space Perception; D013997:Time Factors; D019987:Persons with Visual Disabilities / Q000523:psychology*; D055815:Young Adult