FPGA Based Signal Processing Implementation for Hearing Impairment

Hearing aids partially overcome auditory deficits and normally employed for the hearing impaired people to compensate hearing loss. This paper takes an approach to design a system which have a digital filter bank which can separate the input speech signal into different bands and automatically gain is adjust for individual band. The system is developing on Field Programmable Gate Array (FPGA) platform. The system consists of analog-to-digital (A/D) converter, digital filter bank, gain control and digital-to-analog (D/A) converter. The A/D converter converts the analog speech signal into a digital speech signal. After that input signals gets process by digital filter bank and gain control. For a person with hearing impairment the range of levels between weakest sound that can be heard and the most intense sound that can be tolerated is less than normal listener. For compensating this, hearing aids amplify weak sounds more than they amplify intense sound. The D/A converter converts the output processed signal into analog speech output signal. The speaker converts the analog speech signal into an acoustical output signal that is directed into ear canal of the hearing instrument user.