Abstract
Purpose :
Sensory rehabilitation for individuals with combined vision and hearing impairment often relies on the use of assistive devices (ADs). Some of these Ads are low vision devices that use speech outputs (e.g., talking clock), but in individuals with combined impairment, their use is likely compromised by a concurrent hearing loss. The goal of this study was to evaluate the audibility of low vision devices with speech output in a population of individuals with acquired dual sensory impairment.
Methods :
We measured the ability to correctly repeat speech output presented by three ADs (talking watch, calculator, scanner) and participants’ confidence levels in their response accuracy in 24 participants with visual impairment only (VA = 20/50 to no light perception) and in 22 participants with dual sensory loss (VA = 20/40 to no light perception, mean pure-tone threshold from 28 to 75 dB hearing loss). Testing was conducted under controlled conditions with a background noise of 37.7 dBA. Participants were placed at a fixed distance of 74 cm from the sound source. Phrases were presented at three volumes (the lowest volume representing the intensity at which the AD output is usually presented) and were repeated 1 or 4 times for each volume. Participants were asked to repeat each phrase and rate their level of confidence in their answer on a scale from 1 to 10.
Results :
The pattern of results varied across the different devices. For the watch, an interaction of volume and repetition, and a main effect of category indicated that participants’ success to correctly repeat a phrase and their confidence in their response improved with increasing volume, but more so at higher numbers of repetition (p < .05, ω2 from 0.046 to 0.351). For the calculator, an interaction of volume and repetition, and a main effect of category were obtained both for success and confidence (p < .05, ω2 from 0.002 to 0.324).
Conclusions :
The results indicate that the audibility of the ADs used in this study depended on whether participants had concurrent hearing loss or not. In addition, scores and confidence levels being very low in both categories suggest that even those with normal hearing for their age experienced a certain level of difficulty hearing and understanding speech output. Future device design needs to improve audibility for ADs whose usefulness depends on speech output.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.