Hearing aids use a variety of noise reduction techniques to enhance the experience of hearing impaired listeners. One of these techniques is beamforming, which typically aims to preserve sounds coming from the front of the user and suppresses those from the sides and back. Recently, hearing aids have begun employing a wireless connection between the left and right hearing aids in order to augment the directionality of the beamformers, called binaural beamformers. However, the effect of these binaural beamformers on perceived quality and intelligibility has not been thoroughly tested. This thesis investigated the benchmarking of hearing aids which utilize binaural beamforming algorithms using behavioural testing and computational models. Speech recordings from bilateral pairs of several popular hearing aids were obtained across different processing conditions, and in different noisy and reverberant environments. The quality of these recordings was evaluated subjectively by thirteen hearing impaired adults. In addition, computational predictors of perceived quality and intelligibility were extracted from the left and right hearing aid recordings. Objective and subjective analyses revealed that binaural beamforming has a generally positive effect on quality and intelligibility that was dependent on the directionality of the speech and noise. The ear recording with the better predicted quality score was also found to correlate better with the subjective quality ratings than the average of left and right ear predicted scores. A new weighting function that optimally combines the monaural computational metrics was developed, which was shown to be especially effective in environments where speech and/or noise sources are asymmetrically positioned
