Where did that sound come from? Comparing the ability to localise using audification and audition

Abstract

Purpose: A prototype device was developed to allow individuals to hear ultrasound reflections off environmental obstacles. Previous studies have shown that this device allows for better distance judgement than audition and allows for effective passage through the centreline of apertures. The purpose of this research was to evaluate audification as a method to localise direct sound sources as compared to audition. Method: In an anechoic environment, participants localised point-sound sources for three conditions: auditory, audified ultrasound with receivers facing laterally, and audified ultrasound with receivers facing forward. Results: Azimuth localisation was similar within a range of −35° to 35° in front of the participant among all conditions. At the periphery, −70° and 70°, audified ultrasound was more accurate than audition for novice participants. No difference was evident in user elevation accuracy for these signals among the different conditions. Conclusion: Audification of ultrasound can be effective for localising point-source sounds in the azimuth direction, but more evidence is required to evaluate accuracy in the vertical direction.

Implications for Rehabilitation

• Secondary mobility devices can be used by individuals with visual impairment to avoid obstacles above waist height.

• Audification allows for skill-based response enabling intuitive obstacle avoidance and localization of point sound sources.

• Localization of peripheral sounds was shown in this study to be better with audified ultrasound than audition.

Keywords::

• Audification
• localisation
• ultrasound
• visual impairment
• assistive technology

Acknowledgements

The authors wish to thank the Canadian Institutes for Health Research for the funding support in the form of a Canada Graduate Scholarship. We would also like to acknowledge the significant contribution of the University of Auckland in allowing human testing to be conducted in the anechoic chamber of the Acoustics Research Centre as well as the technical support of Gian Schmid.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.