A Microcontroller-Based Design for Digital Hearing Aid Devices

Microcontrollers are emerging into new applications like smart phones, audio accessories, video gaming peripherals and advanced medical devices, providing highperformance, reliability and low-power consumption for end users. In this paper the design of a microcontroller-based hearing aid device is provided, by which power consumption and hardware area are reduced. The proposed digital hearing aid design comprises the following main components: sound detection circuit, microcontroller, digital to analog converter (DAC) and audio level indicator. The microcontroller used in this work is the high performance enhanced flash PIC18F4520 of microchip which has an on chip analog to digital converter (ADC) peripheral. The ADC features of PIC are used to detect and compare the sound level. ‘C’ and assembly language programs are developed to control the function of the microcontroller. MPLAB Integrated Development Environment (IDE) is applied for the development of the proposed embedded applications employing PIC microcontroller. The DAC MCP4921 is used for analog conversion of the processed signal. The different levels of the audio signal are indicated on the audio level indicator LM3915 in terms of ten LEDs display.