Investigation of the effect of binaural directionality in hearing aids on speech understanding in noise

Binaural hearing improves localization skill and speech understanding performance in noise. In sensorineural hearing loss, localization skills are weakened, speech understanding performance decreases in noisy and reverberant environments. Hearing aids are digital electronic devices used to reduce the negative effects of sensorineural hearing loss. In the use of bilateral hearing aids, binaural directionality is provided by sharing information between the devices through to the wireless connection feature. In this study, it is aimed to investigate the effect of binaural directionality technology called StereoZoom used in Phonak hearing aids on speech understanding performance in noise and satisfaction levels of individuals. Eighteen individuals with bilateral mild, moderate and moderately severe sensorineural hearing loss, between the ages of 18 – 65 and using bilateral hearing aids were included in the study. Three different directionality programs have been created in hearing aids: monaural adaptive, monaural nonadaptive and binaural nonadaptive. In each program The Turkish Matrix Test was applied to all individuals in three different situations; (1) the signal from the front and the noise from right, (2) the signal from the front and the noise from left, (3) both the signal and noise from the front. After a month, Turkish SSQ was applied to the individuals for the three directionality program. It has been found that the speech understanding performance in the binaural nonadaptive directionality is significantly higher than the monaural adaptive and monaural nonadaptive directionality in the first and the second situations (p<0.05). The differences between programs were not significant in the third situation (p>0.05). The differences of Turkish SSQ scores between programs were not significant (p>0.05). It was concluded that the positive results regarding speech understanding performance in noise obtained by binaural directionality were not reflected in satisfaction levels in daily life.