10.6

588Logic Pro User Guide
In theory, the spatial positioning of any sonic experience can be reproduced during
playback, so no special techniques need to be employed during recording. There is,
however, one drawback to this approach:every person has differently shaped ears and
different body and head proportions, all of which influence the way sound signals arrive
at the eardrum—not to mention aspects such as hearing loss, subjective responses to the
sounds being heard, and so on. Given these physical differences, each person listening
to the same sound source, while standing or sitting in the same position, hears slightly
different binaural signals.
Therefore, perfect reproduction would only be possible if you could make a recording with
tiny microphones placed inside your auditory canals. Because this is impractical, binaural
hearing has been emulated in sound laboratories by using mannequin heads with built-in
microphones. This approach has led to binaural recordings to fit the average person, which
are more or less compatible with the way most people hear.
Playback of binaural recordings is best suited to headphones, ideally combined with
signal conditioning (processing) that ensures the signals are accurately reproduced. Given
a specialized listening environment, it’s also possible to reproduce these signals with
loudspeakers, utilizing a process known as crosstalk cancellation.
As you are unlikely to have the technology required to make binaural recordings, your best
chance of simulating binaural signals is by processing the sound signal on playback. This is
known as the head-related transfer function (HRTF), which approximates the change that a
signal undergoes on its way from the source to the eardrum.
Use the Binaural Pan knob in Logic Pro
The Binaural Pan knob is available when Surround is selected in the Advanced
preferences pane.
By setting the channel strip’s panning mode to Binaural, you can use the Binaural Pan knob
to position the signals on the panning plane. The signal that results from using the Binaural
Pan knob is best suited for headphone playback. You can, however, process the Binaural
output using the Binaural Post-Processing plug-in, which allows you to play back the
binaural pan effect through loudspeakers.
You set the channel strip panning mode to Binaural as described in Select a panning mode
for a channel strip.