What features of Siemens binax enabled people wearing them to outperform people with normal hearing in recent studies?
Great question. One study was conducted at University of Northern Colorado (UNC) and one was done at Oldenburg Horzentrum in Germany. These studies showed that there was a 2.9 dB improvement in speech reception thresholds using the Hearing In Noise Test (HINT) for subjects with mild to moderate hearing loss wearing binax technology with the directional microphones activated, as compared to people with normal hearing. That correlates to approximately a 25% advantage in speech understanding. More details of the studies can be found here.
The binax feature responsible for this improved performance is Narrow Directionality. Narrow Directionality uses a much more focused beam with directional beamforming, utilizing that virtual eight-microphone array. With two mics on the left side and two mics on the right side, binax takes the audio data from the mic on the right side and transfers that to the left side, so each instrument is essentially using four microphones. As a result, the beam is very precise in focusing on the signal or person that the wearer wants to hear. It not only suppresses sounds from behind the wearer, but also suppresses sounds at angles outside of the very narrow beam, and it does all this automatically. This is very effective in places with diffuse noise like cocktail parties and restaurants.