Indian Journal of Science and Technology

Abstract

Background/Objectives: To shed light on the history of development of hearing aid, along with the various pros and cons of each developed technological solution. Methods/Statistical Analysis: A historical survey has been conducted, which highlights some of the more renowned and widely deployed hearing aids within the market. The different types of hearing losses and the varying degree of assistance provided by the different technological solutions have been discussed. Over the years, the overall accuracy as well as practicality of the hearing aids have improved, ranging from cumbersome and heavy hearing aids in the early 1960-1970s to the portable and wearable ones available in the market at present. Findings: Technological innovation is spearheading massive improvement within the hearing aids. Some of the key features causing these changes include wireless technology, frequency lowering, directional microphones and digital noise reduction algorithms. Although DSP has provided significant changes in the hearing technology, limitations still exist, which require re-search contributions from different fields like clinical audiology, psychoacoustics and signal processing. Application/ Improvements: Most of the portable and reliable hearing aid devices are very expensive. Therefore, there is a need to develop affordable pieces of equipment that is able to cater to basic hearing functionalities. 
Keywords: Digital Signal Processing (DSP), Directional Microphones, Digital Noise Reduction, Ear Trumpets, Frequency Lowering, Hearing Aid