|
An automatic level control is a part of the recording electronics
that will turn up the volume when a quiet person is talking,
and turn down the volume when a loud person is talking. Simple
telephone recording connectors send the far person's voice
to the recorder much louder than the near person's voice.
They rely on an automatic level control in the recorder to
balance these levels.
The problem is that when the ALC turns up the level of the
quiet near person, they also turn up the level of any background
noise. This background noise which will hten be clearly audible
on the recording will be both background noise in the room,
as well as hisses, buzzes and hums.
The other problem is that if both people stop talking the
ALC will turn up the volume. THis means that silences become
full of noise as the ALC turns up the background noises.
|
