Analysis of existing computerized obstacle avoidance systems has shown that all systems have important limitations: dependency on one sensor type; limited communication capabilities; and failure to reduce the user’s navigation-related physical and mental fatigue. Most of analyzed systems use binaural method or it’s modified version. The model of sutrasonic sonar was defined and programmed during this study. The results of analysis of environment using the model have shown that ultrasonic sonars can be used to help blind and visually impaired people.