Digital hearing aids have systems (directional microphones and noise reduction) that detect if you are in a quiet or noisy environment and the source of sound. The hearing aid adjusts its settings to optimise performance. One way to combat the issue of distinguishing speech in noise is a feature on many hearing aids called directionality. Directional systems all have two or more microphones separated by a specific distance on a hearing aid. The difference in the arrival time of sound to each of these microphones dictates how the hearing aid responds to the sound. One note: directional microphones in general focus on amplifying the sound in front of a listener. With the use of adaptive directionality, people who have hearing disabilities are able to hear better. The way it works is that it it controls the sound around you. It can detect if, for example, you are in a quite room, so that a person with hearing disabilities know that it is just quite in the room, not that they can not hear anything. In that way they know the problem is not in them, or the problem is not that the hearing aid doesn+t function properly. Also if the sound is too loud, the adaptive directionality makes the sound sound normal to you.