William R. Wiener

Independent Travel for Developmentally Disabled Persons: A Comprehensive Model of Instruction.

Independence and self-determination are long established goals for developmentally disabled persons. Some aspects of independence depend upon the ability to to gain access to resources in the local community. As a result, the acquisition of independent travel skills has received much attention over the years. However, most attempts to teach travel skills to this population have been limited in scope. This paper advocates a more comprehensive approach based upon the principles used to teach orientation and mobility to blind and visually impaired people.

Acoustic analysis of the Sonic Guide

The Sonic Guide is an eyeglass configured sonar‐type device available for the orientation and mobility of blind individuals. It operates by emitting toward and receiving from target objects modulated stimuli whose intensity and frequency components directly result from the distance and physical properties of the target. This investigation measured the sound pressure level output, via a sound level meter, of four Sonic Guide temples, at three volume control settings, for six octave frequencies (250–8000 Hz), at six distances (35.6 cm–4.6 m) for a total of 432 measurements. Means, standard deviations, and an ANOVA were computed to investigate the consistency of output across temples and the interactions among frequencies with volume control setting and with distance. Across temples, the Sonic Guide devices were found consistent at each volume control setting, at each frequency, and for each distance measured. Higher volume control settings produced proportionally greater output in the higher frequencies tha...

Selection of attractor sounds for an audio‐based navigation system for the visually impaired

Research into human hearing has been very laboratory oriented in the sense that the test environments do not replicate most real world situations [J. C. Middlebrooks and D. M. Green, Annu. Rev. Psychol. 42, 135–159 (1991)]. While very useful information is gained from these types of tests, it is difficult to see how real world situations affect sound source localization, recognition, and navigation (walking/way finding) performance. Such information is especially important to people who are visually impaired and dependent on prior knowledge of the environment or audio cues for travel. The research reported here was conducted during the development of an audio‐based navigation system. The question that arose was, what constitutes good attractor sounds versus bad sounds? A series of physical tests was developed to identify sounds that performed best from within a group of real‐world attractor sounds. Testing was conducted with the aid of participants who were blind or visually impaired. Results of the experiments were consistent with those of Landau et al. [Asst. Technol. 17, 133–143 (2005)].