Comparison of two orientation systems for indoor travel of blind persons with mental retardation.

Two blind women affected by severe mental retardation were exposed to two previously developed orientation systems. One of the systems was based on acoustic cues, the other on vibratory feedback. The aim was to assess the relative effectiveness of the two systems. Data indicated that the acoustic system ensured a higher frequency of correct moves for one of the subjects and a more rapid performance of the moves for both subjects. The findings are reviewed in relation to the characteristics and applicability of the systems.