The electroacoustic performance of digital noise reduction systems in commercial hearing aids with Malay speech-plus-noise test signals

One of the most frequent complaints of hearing-impaired individuals is difficulty understanding speech in noisy environments. In order to improve listening comforts in background noise, digital noise reduction (DNR) has been incorporated into the hearing aid. However, each hearing aid manufacturer has their own proprietary algorithm for their DNR. Therefore, this study aimed to evaluate the efficacy of the DNR system in commercial hearing aids using the Malay speech-in-noise test. Electroacoustic testing has been performed on six hearing aids that have similar technology but different brands using newly developed Malay speech-in-noise test signals in the condition of DNR on and off. The total root-mean-square (RMS) gain reduction for each HA was calculated. The results show that the type of noise, the signal-to-noise ratio (SNR) and the gender of the speaker have a significant effect on the amount of gain reduction shown by the DNR of the tested hearing aids (p<0.05). In conclusion, clinicians need to measure and understand methods to verify the functionality of DNR before fitting a patient's hearing aid to ensure its effectiveness in real life.