External microphones can be connected for higher-quality recording, or for achieving optimal microphone placement.
A camera is often mounted in the corner of the room near the ceiling, although this placement is not ideal for a microphone, since the hard surfaces of the ceiling and walls create reverberations and distortion in the sound. If possible, place the microphone away from large, flat surfaces.
Sound propagating through the air is subject to attenuation, meaning that as distance increases, the intensity of the sound will gradually diminish. Doubling the distance will lead to a four-fold drop in sound intensity.