What can I do with a binaural microphone?
Anytime you want to capture the spatial qualities of a sound event, a binaural head microphone makes it easy.
Some examples:
1. Capture the spatial qualities of an audio system set up in a room or a car so a listener can experience those
qualities over headphones in a remote location or at a dierent time. This can be very useful for presenting
the benets of audio equipment or advanced system optimization using a previously optimized system as an
example.
2. Capture a soundscape to serve as a sonic environment when making industrial, training or informative
videos.
3. Capture the sound of ambient noise so that equalization can be designed into an audio system to mask the
eects of such noise.
4. Capture the sound of environmental noise for analysis.
5. Add realism to a recording of any live event—birthday parties, hikes, school plays or concerts. Your
imagination is the limit.
6. Make eld recordings of natural events or the sounds of animals.
7. Learn about the eects of Head Related Transfer Function (HRTF) and sound localization.
Making binaural recordings with the BHM-1
A binaural head microphone makes it easy to capture the spatial aspects of sound in dierent environments
and to experience those spatial aspects when listening to playback over a good pair of headphones.
Compared to other means such as: a) binaural rendering of standard stereo recordings, b) synthesizing of a
space using a recording made with an ambisonics microphone and a digital audio workstation plug-in or some
other computer program, a direct binaural recording made with a head mic is faster and easier and doesn’t
include a steep learning curve. You just place the mic, record the event and play it back.
How does the head mic capture all of the spatial qualities?
We hear spaces because sounds that arrive at our ears from sources placed at various distances and angles
in 360-degree space arrive at our ears at dierent times and at dierent levels. In addition, the shape of our
head and torso and the shapes of our ears changes the frequency response of the sound when it arrives from
dierent angles of azimuth and elevation. Making a recording using a microphone shaped like a head with
microphones in its ears captures all of those dierences automatically.
The frequency response changes that are the result of dierent orientations in elevation and azimuth are
commonly referred to as Head Related Transfer Function, or HRTF. We have documented the HRTF of the
BHM-1 at 15° increments in both azimuth and elevation and those measurements are included in the appendix
of this manual. The measurements have been saved as simple .txt les and can be easily imported into many
measurement and analysis programs. The complete set of measurements is available for download on the
BHM-1 section of www.audiofrog.com.
When we listen to a binaural recording (made with a head microphone) through headphones, the timing of the
arrival of sounds and their frequency responses recorded by the head microphone--the head microphone’s
HRTF-- replaces the HRTF of our own head. The result is an astonishingly believable recreation of the
recording space.
Making the recording is simple. Attach the BHM-1 to a tripod or a microphone stand and place the stand so
the head is in the same place and in the same orientation as a listener’s head would be if the listener was
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