When recording conference calls with microphones, the first thing to consider is how many people will be speaking during the call [source: Jake Ludington's MediaBlab].
Many conference calls are one-too-many events in which a single presenter does most, if not all of the talking. In that case, recording the conference call isn't about recording conversations between many people, but recording an individual speaker. For a one-to-many conference call, you'll only need one microphone positioned in front of the presenter [source: Jake Ludington's MediaBlab].
Another type of conference call is a few-too-many setup, in which three or four speakers take turns presenting information to the rest of the teleconference participants. To achieve the best sound quality when recording a few-to-many conference call, you'll want to have a separate microphone for each presenter [source: Jake Ludington's MediaBlab].
In any recording situation where you have multiple microphones, you'll have to adjust each microphone's level so that one presenter doesn't sound really quiet in the recording, while another sounds really loud.
To do this, all the microphones will have to be connected to a mixer. The mixer assigns a different track to each microphone. An audio technician can use the mixer to adjust the amplification of each track until they reach the line level (0.5-2V) or recommended base level for audio recording [source: Media College].
There are two basic types of microphones: multidirectional and unidirectional. Multidirectional microphones have a "multiple pickup pattern" meaning they can record sound coming from several different directions at once [source: FilmSound.org]. Unidirectional microphones only pick up sound from the area directly in front of the microphone's head. A popular type of unidirectional microphone is a small lavaliere or lav microphone that can be clipped to the lapel of a shirt [source: The Sound Professionals].
Unidirectional microphones are useful for one-too-many conference calls since there's only a single presenter. To avoid having to use a mixer for a few-too-many conference call, you could buy a multidirectional table microphone to record many presenters at once.
There are even professional conference microphones especially designed for large conference rooms. These microphones are programmed to automatically adjust levels and to boost the common frequencies for human speech. Several table microphones can also be "daisy chained" together to extend over very long conference tables [source: Soniclear].
To record a conference call using a microphone, you'll also need to plug the microphone or mixer into a tape cassette recorder or a digital recording device. In the next section, we'll explain how to record a conference call using digital devices and computers.