AMPLIFIERS FOR HEARING AID

Abstract

Hearing impairment is an obstacle to communication for many people. The most indicated treatment in most cases is the use of sound amplification devices. Hearing aids basically consist of a circuit that captures external sound and amplifies the signal into the patient's ear. In Brazil, there is still a lot of difficulty in acquiring the device, mainly because of its high cost. The present work proposes to investigate simpler alternatives for the amplifier circuit, in order to facilitate access to treatment in cases of mild and moderate losses. The chosen circuits were analyzed through simulations, both in the time and frequency domain, according to their amplification performance for signals in the audio range. After the simulations it became explicit which adjustments needed to be made for the improvement of these circuits, so that it can be used as an audio amplifier. Although both amplifiers analyzed showed some inadequacy for use as a disease treatment, one of the circuits showed a performance that meets much better what is desired in this application, with sufficient gain for correction of light losses practically constant in much of the sound frequency range, while the other did not perform as expected. Although some adjustments are needed, the first circuit showed promise for application in cases of mild losses, and can be further developed to also serve moderate cases.