Previous Work by Others

Others have addressed this issue in various ways.

Crumbs

The NCSA Biological Imaging Group (Brady, 1996) observed that many early attempts at sonification were difficult to listen to for long periods of time, because the tones generated were repetitious and the chords typically dissonant. Their goal was to build a system that would generate sound which would be both melodic and unobtrusive. The Crumbs software they developed rotates through several different melodies, all based on the dorian scale. As the user begins searching with a probe for fibrous tissue in the data set (generated from an MRI scan of a horse's leg), the sound of a guitar playing a melody is generated. As the user gets closer to the goal, other instruments are added in order, a piano in single register, a piano in multiple registers, a voice-like synthesized instrument, and a flute. All five instruments are heard when the user reaches the most dense region of fiber.

The vOICe

Peter Meijer has developed The vOICe, an experimental system for auditory image representation (Meijer). His system coverts a picture into a 64 x 64 pixel digital image in gray scale. The picture is then scanned from left to right, one column at a time. Each row of the picture is interpreted as representing a particular sound frequency. While a particular column is being scanned, the 64 sound frequencies are generated with the volume of each frequency based on the brightness (within 16 levels) of the corresponding pixel. The result is a changing sound pattern with duration of about 1.5 minutes. The goal of his work is to assist blind people in understanding the environment around them (for example, recognizing the position of doors in a large room).