Development of an Electronic Stick with Audio Sensory Perception for the Visually Impaired

The report details the use of ultrasonic transmitter and receiver for distance measurement which can be embedded in a stick thereby providing navigation assistance to the visually impaired. As the human ear’s audible perception range is 20 Hz to 20 kHz, it is insensitive to ultrasonic waves, and hence the ultrasound waves can be used for applications in industries/vehicles without hindering human activity. The distance is measured using pulse echo method. The measurement unit uses a continuous signal in the transmission frequency range of ultrasonic transducers. The signal is transmitted by an ultrasonic transducer, reflected by an obstacle and received by another transducer where the signal is detected. The time delay of the transmitted and the received signal corresponds to the distance between the system and the obstacle so depending on this time value a beep frequency is generated which indicates the closeness of the obstacle to the system.