Evaluation of Digital Signal Processing Algorithms in Hearing Aids with Ear to Ear Synchronization

Abstract

The aim of the present study was to check the benefit of directionality and DNR algorithms of binaural WDRC wireless technology hearing aids on speech intelligibility in a noisy environment. The study had included 14 participants (between 27-55 years of age) with bilateral mild to moderate flat sensorineural hearing loss. Two hearing aids with wireless technology were programmed and fitted. SNR-50 was obtained using sentences in the conditions with and without wireless option, directionality and DNR algorithms. The sentences were played through a speaker at a fixed angle of 0°. Calibrated speech babble was used as noise and the babble was routed through speakers in 0°, 90°, 270° and in both 90° and 270° at a fixed presentation level of 70 dB SPL. The level of speech was varied till SNR-50 was achieved. The mean SNR-50 ranged from + 3.0 dB to + 7.5 dB. Friedman test and Wilcoxon signed rank test were carried out for statistical analysis. Results revealed that there was a significant improvement in SNR-50 using the wireless synchronization hearing aids when compared to deactivation of wireless synchronization option. Activation of directionality and DNR together, and activation of only directionality significantly further improved the speech perception in noise.