I am a classical guitar player and I originally modeled these ears to make accurate recordings of myself playing my favorite pieces.
I have always found traditional recordings, even the professional classical music ones, to be lacking in realism.
They can sound great and bigger than life when well done, but never like a realistic representation of the music.
There is always a sense of artificiality due to the recording technique employed, and that's probably the main reason why many people think that stereo systems never quite sound like the real thing. They blame the playback system (admittedly not without good reasons, with many playback systems), but disregard the main thing: the signal that is encoded in the recording itself.
So I started investigating various recording techniques, and ended up choosing binaural for the best possible results in terms of accuracy.
I believe if you are visiting this page you have come to the same conclusion.
I have worked on my DIY binaural microphone for years, perfecting it in every way I could think of, from selecting the right head, to microphone capsule choice, to the most important part of it: the ears.
Why anatomically accurate ear canals?
Evolution provided us with ears to be able to hear our surroundings.
Eardrums are the auditory transducers that sense air pressure and, through the middle and inner ear, provide signals to the brain.
Our brain's constant processing of left and right eardrum sensed pressure inputs is what makes us hear. These inputs vary depending on the nature of the source, but also on the source location in respect to the listener.
Our head and outer ears (pinnae and ear canals) play a fundamental role in shaping the pressure frequency content that reaches the eardrums, applying filters that vary depending on the location of the sound source and known as Head Related Transfer Functions (HRTFs).
The geometry of our outer ears literally shapes the sound wave before it hits the eardrum, so that the brain is able to interpret left and right eardrum signals correctly and recognize and locate the sounds around us.
Without ears and ear canals, localization and sound recognition are compromised.
Binaural recordings aim at encoding the pressure that our eardrums would sense if our heads where in the place of the microphone directly on the records, to be able to be retrieved by our brain during playback.
To provide the microphones with the correct sound pressure waves it is therefore essential to use anatomically accurate replicas of the pinnae and the ear canals, in a binaural microphone. This ensures that the left and right microphone sensed pressures encoded in the recording are the same ones that our eardrums would experience, for our brain to interpret them and let us enjoy the ultimate in sound accuracy and realism.