Experimental investigation of a bone-conducted ultrasonic hearing system based on a DSP platform

Abstract

Ultrasonic signals can be conducted and perceived by bones when a certain part of human skull is pressed. Experiments show that hearing-impaired people may be able to perceive ultrasound, distinguish different frequencies, or even recognize words after training. This finding is very promising for hearing-aid studies. In this paper, a novel bone-conducted ultrasonic (BCU) hearing system is developed. Both the software simulations and experiments on human subjects are carried out. The BCU hearing system is implemented on a DSP platform to achieve an appropriate modulation strategy. An ultrasonic vibrator is attached to the system, allowing the audible sound signals to be demodulated from the ultrasonic region via bone conduction. Different carrier frequencies and modulation algorithms are examined and validated in this platform. To evaluate system performance, perception tests are also conducted on the deaf and normal-hearing subjects. Experimental results show that the proposed system can operate as a flexible experimental platform suitable for BCU hearing studies.