The directivity factor (DRF) is a dimensionless characteristic value of loudspeakers and microphones that is specified in gamma. It is a measure for the ratio of a certain radiation characteristic to a spherical sound radiation.
The same applies to the sound pickup of microphones. Here, the sound pickup of a microphone with a certain directional characteristic is put in relation to the sound pickup of a microphone with an omnidirectional characteristic.
The result is that the directivity is a dimensionless value and must always be >1, since all radiation patterns and directional patterns have a more
The degree of bundling is decisive for the sound pickup of ambient noise. The higher it is, the less sensitive the audio pickup is to ambient room sound.