A microphone that picks up sound better from one direction than from another. Examples of directional microphones are cardioid, super cardioid, hyper cardioid, bi-directional, stereo.
a microphone that is more sensitive to sound coming from one direction than from another; a directional hearing aid uses a directional microphone to enhance reception of signals at the front relative to those from the back.
An omni-directional hearing aid picks up sounds from all directions equally. Directional microphones enable hearing aids to amplify sounds coming from the side or behind the wearer less than they amplify sound coming from directly in front of them. This can make listening more comfortable in background noise as long as the listener is within a couple of metres of what they are listening to. The benefit of a directional microphone is greatest when the noise is coming from a single direction and there is little reverberation (echo).