Signal-to-noise ratio of augmentative and alternative communication devices across educational settings

Abstract

The use of augmentative and alternative communication (AAC) devices is
important for individuals whose natural speech is inadequate for communication.
Research conducted to make improvements to AAC devices has included exploring the
effectiveness of color-coding symbols, linguistically based arrangement of symbols, and
intelligibility of the devices. However, little attention has been given to the volume
adequacy of AAC devices in a variety of educational settings. It is hypothesized that
volume levels of AAC devices are often inappropriate for adequate communication when
compared to noise levels in the classroom. The present study measured the volume
output level of AAC devices compared with background noise levels at strategic
distances of three feet ( one-on-one setting), six feet ( comfortable conversation distance),
and twelve feet (teacher instruction). Signal-to-noise levels were compared for seven
individuals in the settings in which each student actively participated using their device.
Additionally, this study investigated the compensatory strategies related to inadequacies
of volume output levels for AAC devices through qualitative observation and field notes.
The results of the present study indicated that the AAC devices of all seven children were
not set at adequate levels for effective communication in the classroom setting. It was
also determined that the participants commonly used several strategies to compensate for
poor signal-to-noise ratios. These included repetition, gestural or tactile cues, and timing
speech to quiet moments to improve audition of the devices to listeners. In addition, the
participants' communication partners asked for repetition and angled the AAC devices to
both see and hear the intended message.

Date of Award	2012
Original language	American English
Awarding Institution	Eastern Illinois University
Supervisor	Tena L. McNamara (Supervisor)