Effect of Different Signal Enhancing Technologies on Speech Recognition in Noise

Abstract

A major consequence of sensorineural hearing loss (SNHL) is communicative difficulty, especially in the presence of noise and /or reverberation. The purpose of this investigation was to compare three types of technologies that have been shown to improve the speech perception performance of individual with SNHL: directional microphones (DMic), digital noise reduction (DNR) and frequency modulation (FM) system. 23 adult subjects with moderate to moderately severe SNHL served as subjects. Speech identification scores and signal to noise ratio (SNR) measurements were used to understand the benefit of these technologies in the presence of noise. These measurements were carried out in four listening conditions such as unaided, DMic, DMic+DNR and FM.Results revealed that speech perception in noise was significantly better with FM technology than with the other two listening conditions (DMic and DMic+DNR) in both SNR and speech identification measurement. There was no significant difference in performance between DMic and DMic+DNR listening conditions in SNR measurement. Even though the statistical analysis showed significant difference in performance between DMic and DMic+DNR listening condition in speech identification there was only an average of 2-3% improvement in speech identification with DMic+DNR over DMic.