title: What's that sound? Distance determination and aperture passage from ultrasound echoes.
abstract: OBJECTIVE
  Individuals with visual impairment have difficulty detecting obstacles that are above waist height. A prototype device was developed to allow individuals to hear ultrasound reflections off environmental obstacles. The purpose of this research was to evaluate novices' ability to evaluate distance and pass through apertures using this device.
  
  
  METHODS
  The first experiment evaluated the ability to judge the distance from a wall using the ultrasound system as compared to using auditory echolocation. The second examined time for passage, centreline accuracy and angle of rotation through different sized apertures.
  
  
  RESULTS
  Distance judgement was found to be better with audified ultrasound than with auditory echolocation. When passing through apertures, audified ultrasound enabled centreline precision similar to that of vision, but individuals did not rotate their shoulders while passing through suggesting that more practice is necessary to combine perceptive information with proprioceptive action.
  
  
  CONCLUSIONS
  The ability to judge distance and navigate through an environment with obstacles using a device which audifies ultrasound was shown to be better than using auditory echolocation, but not as effective as vision. This device will allow individuals with visual impairments to better detect and avoid environmental obstacles.
authors.affiliation: University of Auckland, Auckland, 1142 New Zealand. c.davies@auckland.ac.nz
authors.forename: Theresa Claire
authors.initials: TC
authors.lastname: Davies
authors.forename: Shane D
authors.initials: SD
authors.lastname: Pinder
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Burns
mesh_terms: D000704:Analysis of Variance; D005260:Female; D006297:Health Services Accessibility; D006801:Humans; D007600:Judgment; D008297:Male; D012656:Self-Help Devices; D013017:Sound Localization; D018608:Ultrasonography, Doppler; D014786:Vision Disorders