An FPGA Implementation Of Hearing Aids based on Wavelet-Packets

Advances in digital signal processing and microelectronics have led to the development of superior digital hearing aids for ameliorating severe defects of hearing. The progress in field programmable gate arrays (FPGA) technology, especially for miniaturized system applications, allowed increasing sophisticated features to be built for better sound reproduction, keeping small size and low power consumption of the devices. In this paper the recent trend of combining interconnects of FPGAs with embedded microprocessors and related peripherals to form a complete system on a programmable chip is employed for the design of digital hearing aids. Wavelet packet transform is applied for speech compensation of the hearing loss. The wavelet packet module is described in VHDL, implemented on FPGA and then added as a peripheral to the processor system. The embedded software processor used is the MicroBlaze soft core processor. The chip used is Digilent XUP II Virtex-II Pro system FPGA containing audio codec LM4550. The features of the design are small area and fast processing and low cost.