In 1997 there were 227,000 deaf people in the US who could not use regular auditory sensing to gain awareness of sound. Instead, they use alternate awareness techniques such as sensing vibrations and the use of flashing lights to substitute for the aural sensing of sound in the workplace. However, there remains a gap between the experience of a hearing individual and the experience of a deaf person. Our work describes the design and evaluation of a peripheral display to provide the deaf with awareness of sound in an office environment to help close that gap. Conceptual drawings of sound by hearing participants, exploration with paper prototypes, interviews, and surveys formed the basis for our current design.
We implemented two prototypes shown in Figures 1 and 2. One is based on a spectrograph, a tool commonly used by speech therapists that represents pitch and intensity of sound over time. Another depicts position and amplitude over time. We evaluated them in a dual task experiment with eight deaf participants and found they were able to peripherally identify notification sounds such as a door knock or telephone ring with both systems while performing a visual primary task. Participants had significantly higher identification rates with the visualization that represented position. Neither visualization resulted in a significant amount of distraction in terms of performance of a primary task. This work  has been received with much enthusiasm by members of the deaf community and may ultimately result in a system for better support for sound awareness for the deaf in situations of fixed visual focus.
Figure 1: A cellular phone ring as represented by our spectrograph visualization. In this visualization, height is mapped to frequency, color to intensity (blue = quiet; red = loud). The temporal aspect is depicted by having the visualization animate from right to left. A cellular phone ring is recognizable by a regular frequency amplitude pattern. This is typical of mechanical sounds.
Figure 2: A cellular phone ring as represented by our ripples visualization. A top view map of the room appears in white. The rings denote the position of a sound source in a room. The size and color of rings indicate the amplitude of the sound. Frequency does not appear in this visualization. A user can infer a sound source from its location. In this case, the participant was told the phone was on the desk. Thus, a sound coming from the desk would probably be the phone.