Review on High Frequency hearing loss reduction methods in Digital hearing Aid

Abstract

A high frequency hearing loss will affect a person’s ability to understand speech. People with high
frequency hearing loss can hear vowels just fine, but what they can’t hear are the consonant sounds of F, S, T, and Z.
Additionally, they are unable to hear higher octaves, like a woman’s or a child’s voice, or a bird chirping. Losing
hearing in those frequencies means that those sounds are harder to discern. For individuals with severe or profound
hearing loss at high frequencies, it is simply not possible to restore audibility to normal levels using only
amplification. As conventional hearing aids (HAs) have largely failed to provide such individuals with highfrequency cues, alternative methods of signal processing have been considered that present information from highfrequency regions of speech to lower frequency regions. The method to be discussed in this article is commonly
referred to as frequency lowering (also known as frequency shifting, frequency compression, or transposition).