Implementation of a Noise Reduction Algorithm in a Hearing Aid Device Based on a dsPIC

Abstract

Nowadays there are many people affected by hearing impairments. The cost of assistive listening devices leaves out of reach for many people a technological solution. In the search of an economical alternative, low-cost DSPs arises as a good choice. However, it could be difficult to decide which has the best cost -effectiveness trade off among all devices offered in the market. The main goal of this work, then, is to determine the memory requirements of three noise reduction methods. It is done in order to select the algorithm that uses fewer resources, which will be implemented on a hearing aid device based on a low-cost DSP. This assistive listening device through digital signal processing techniques can get the basic features of a highend assistive listening device. Objective experiments are performed to analyze the performance of the implemented system..

An Improvement of the Output SNR of an Assistive Listening Device Using Crosscorrelation

“…There are several methods to improve the SNR of a signal by means of monoaural techniques [2], [4], but data memory limitations exist [3]. Hence, due to this restriction, one of the best methods to improve the SNR is the cross-correlation algorithm [5], [6], which allows to improve the SNR by using two monoaural systems as an array of microphones.…”

“…One of the most widely used approaches is the singular values decomposition (SVD) method [2], [3]. This technique decomposes a signal to obtain its singular values.…”

Acoustic Feedback Cancellation in Efficient Hearing Aids using Genetic Algorithm

“…The vital feature of the assistive device, is to improve the signal to noise (SNR) under any type of background noises. The another important factor is to determine the memory requirements for the noise reduction methods to be used [6]. The DSP based hearing aids, functions for voice compression, noise reduction and dynamic equalization tasks to produce better results in hearing operations.…”

“…Also it is necessary to improve the convinience of the user. Hence the SNR ratio of the output signal is maximized, so that the sounds perceived by the person can be heard more naturally [6]. The hearing aids undergo classification of sounds signals and adaptation of signals among the noisy or quiet environments.…”