Apple Final Cut Pro 6 - Manual (Page 813)

28 Part I Audio Mixing
Here are some tips for distinguishing stereo from dual mono recordings:
 Stereo recordings must have two independent tracks. If you have a tape with only
one track of audio, or a one-channel audio file, your audio is mono, not stereo.
Note: It is possible that a one-channel audio file is one half of a stereo pair. These are
known as split stereo files, because the left and right channels are contained in
independent files. Usually, these files are labeled accordingly: AudioFile.L and AudioFile.R
are two audio files that make up the left and right channels of a stereo sound.
 Almost all music, especially commercially available music, is mixed in stereo.
 Listen to a clip using two (stereo) speakers. If each side sounds subtly different, it is
probably stereo. If each side sounds absolutely the same, it may be a mono
recording. If each side is completely unrelated, it is a dual mono recording.
Interleaved Versus Split Stereo Audio Files
Digital audio can send a stereo signal within a single stream by interleaving the digital
samples during transmission and deinterleaving them on playback. The way the signal
is stored is unimportant as long as the samples are properly split to left and right
channels during playback. With analog technology, the signal is not nearly as flexible.
Split stereo files are two independent audio files that work together, one for the left
channel (AudioFile.L) and one for the right channel (AudioFile.R). This mirrors the
traditional analog method of one track per channel (or in this case, one file
per channel).
Digital Audio
Digital audio recording works by recording, or sampling, an electronic audio signal at
regular intervals (of time). An analog-to-digital (A/D) converter measures and stores
each sample as a numerical value that represents the audio amplitude at that particular
moment. Converting the amplitude of each sample to a binary number is called
quantization. The number of bits used for quantization is referred to as bit depth.
Sample rate and bit depth are two of the most important factors when determining
the quality of a digital audio system.