Vibratory-coded directional analysis: evaluation of a three-microphone/four-vibrator DSP system

A sound localization aid based on eyeglasses with three microphones and four vibrators was tested in a sound-treated acoustic test room and in an ordinary office. A digital signal-processing algorithm provided a determination of the source angle, which was transformed into eight vibrator codes each corresponding to a 45 degrees sector. The instrument was tested on nine deaf and three deaf-blind individuals. The results show an average hit rate of about 80% in a sound-treated room with 100% for the front 135 degrees sector. The results in a realistic communication situation in an ordinary office room were 70% correct based on single presentations and 95% correct when more realistic criteria for an adequate reaction were used. Ten of the twelve subjects were interested in participating in field tests using a planned miniaturized version.