Exploration of Head Related Transfer Function and Environmental Sounds as a Means to Improve Auditory Scanning for Children Requiring Augmentative and Alternative Communication.

Many individuals who require augmentative and alternative communication (AAC) cannot directly select items on computer-based displays. Individuals who also have visual impairments may need to rely on sequential announcement of array choices in auditory scanning. The method is challenging and there is a lack of research to improve this access method. Two potential solutions were tested: using environmental sounds to represent items (e.g., the sound of a clock ticking for a clock) and providing spatial cues regarding the organization of items (e.g., presenting auditory information and altering temporal and spectral features so that sounds are heard as left, right, up, or down relative to each other). The individual and combined effects of these cues were tested with typically developing 3-year-old children. After collecting and validating a set of stimulus sounds, 24 children participated in a within-subjects design with four conditions (spoken word label only, associated environmental sound only, spoken word label with spatial information, associated environmental sound plus spatial information). Dependent measures included reaction time (RT) and accuracy. Results indicated that the use of sounds without any spatial cues revealed slower RTs than any other conditions. Also, sounds regardless of spatial cues led to less accurate scores than words.