Affordable Frequency Selective Hearing Amplifier

Abstract

One of the most prevalent diseases affecting human communication is hearing loss. About one in every six people has a hearing deficit globally. Many people suffer from hearing loss but cannot afford a hearing aid because of the high cost set by manufacturers. In this study, we aim to design a frequency-selective hearing amplifier that could be used as an alternative to hearing aids by having an external controller and separate earpieces. The controller allows the user to select the correct frequency bands to be amplified according to the listeners’ degree of hearing loss. As a starting point, we have divided the frequency range of hearing into three bands: 125 Hz to 1 kHz, 1 Hz to 4 kHz, and 4 Hz to 8 kHz. The microphone picks up the signal, and the Analog-to-Digital Converter (ADC) converts the signal to digital form which then goes through a microcontroller where filtering and amplification take place. The amplified frequency band of the signal is then added to the rest of the signal and rescaled before a Digital-to-Analog Converter (DAC) converts the signal to an analog form. Analog signals would go through a second amplifier to adjust the overall speech level that can be heard via the earpiece. The circuit components in the amplifier could be adjusted to produce the desired amount of amplification. The proposed design is tested thoroughly to ensure that a wide range of amplification is achieved for a wide range of listeners with various degrees of hearing loss.