Microphones on hearing aids or other assistive listening devices that pick up sound from all directions. Omnidirectional microphones are important for ensuring that sound is detected from the front, sides, as well as behind the listener. The downside of omnidirectional microphone settings is that if unwanted noise is present behind the listener, they will hear the noise. For this instance, directional microphones are useful.
Everyday Hearing > Omnidirectional Microphone