atolonen on 14/6/2006 at 13:04
Quote Posted by Phydeaux
...Not just left/right, but also some front/back, even though it's just 2 channel stereo. Somehow I think it has more to do with brain interpretations/expectations than the actual recording...
Indeed. I was amazed that it could be done with only two channel stereo too. But then again hunams only have 2 ears and somewhat "limited" ways how the sound can travel to the eardrums, so I guess it's quite possible with certain delay trickery, phase tweaking, etc. The brain expecting certain things might very well be a factor too. Thanks for the Zappa recommendation. I've actually done some soundwork with standard stereo width, phase, and delay equipment where the sound ends up inside your head of seemingly far wider than where the headphones are. I do this all the time in post processing my music to make too mono sounds wider.
Para?noid on 14/6/2006 at 13:19
Quote Posted by atolonen
Indeed. I was amazed that it could be done with only two channel stereo too. But then again hunams only have 2 ears and somewhat "limited" ways how the sound can travel to the eardrums, so I guess it's quite possible with certain delay trickery, phase tweaking, etc. The brain expecting certain things might very well be a factor too. Thanks for the Zappa recommendation. I've actually done some soundwork with standard stereo width, phase, and delay equipment where the sound ends up inside your head of seemingly far wider than where the headphones are. I do this all the time in post processing my music to make too mono sounds wider.
The brain relies on thousands of cues. I dunno how Holography works, but it could be done by manipulating three major factors of human sonic spatial awareness:
1. Head Related Transfer Function: The head, body and torso absorb sound before it reaches your ear. Sounds from below sound more "muffled" than sounds from the right because your body gets in the way. By studying an AVERAGE head related transfer function and developing the right kind of filtering on a signal, we can produce "fake" sources that aren't actually where they say they are.
2. Interaural Time Difference and Intensity: We localise sounds by how quickly they take to get from one ear to the other. Volume plays a part in this. The fact that holophony is more effective on headphones suggests that IID is being put into effect as well as ITD, which is the principle of panning.
3. Reverberation: Reflections of an original sound source reaching the listener after the direct source have an affect on gauging distance, but this is very subtle in the case of the example and would require a complex reverb processor if it is used.
I think what you need is a shitload of microphones and some time fucking around with pan, volume and filter controls. HRTF's are complex functions that have a lot of special cases depending on distance, and these are hard to replicate. At some point today I'm going to try and do this with two condensor microphones and someone's head.
Schattentänzer on 14/6/2006 at 14:09
Quote Posted by Para?noid
At some point today I'm going to try and do this with two condensor microphones and someone's head.
Actually, that's how they record it in practice. They position a dummy with two mics in place of it's ears and do the mambo.
At one point I've downloaded several documents on holophony because I was curious on if it was possible to adapt the effect to a pre-recorded sound. Turns out it's possible but rather difficult.
Old thread on the topic: (
http://www.ttlg.com/forums/showthread.php?t=97497)
scumble on 14/6/2006 at 14:48
I suppose the trouble you'd have with ordinary microphones is picking up a "wide" enough sound image, similar to the directional spread picked up by the human ear.
Stitch on 14/6/2006 at 14:59
Quote Posted by PigLick
this kinda shit makes me wanna invoke piglicks rule again. Fuck I am sure we all read news sites.
Yeah, let's see if we can get this forum down to one new thread a day, then perhaps I'll be able to give up on it altogether.
Para?noid on 14/6/2006 at 19:00
Quote Posted by scumble
I suppose the trouble you'd have with ordinary microphones is picking up a "wide" enough sound image, similar to the directional spread picked up by the human ear.
Not if you treat the microphone like a human ear. If I were to install two small microphones in the ear canals of a dummy, it should do the job. I'm going to try taping two microphones to someone's face for now and see if it does anything worthwhile.
Hewer on 14/6/2006 at 21:15
Quote Posted by Hier
A buddy of mine has a weird hearing disorder that affects sound within a certain frequency range that's usually in the middle of the range most humans can hear. It's very strange because he can hear sound on either side of the range just fine. I suppose it's the auditory equivalent of being colourblind.
Anyway, the amusing part is that it's the frequency range that encompasses most female voices. The doctor told him he should consider himself lucky. :D
My brother has that same- what, condition, I guess. Our mom got pneumonia when she was pregnant with him, and we were told he got some sort of nerve damage from it or somesuch. He did terribly in school- we were told he was slow bordering on mentally retarded until he got hearing aids and was finally able to hear his female teachers. After that he did fine.
Schattentänzer on 14/6/2006 at 21:28
Quote Posted by Para?noid
Not if you treat the microphone like a human ear. If I were to install two small microphones in the ear canals of a dummy, it should do the job. I'm going to try taping two microphones to someone's face for now and see if it does anything worthwhile.
Hmm, I'm not too good with the biology, but I
think the human ear hears different frequencies with different volume.. so some filtering behind the mics could be neccessary.
Jonesy on 14/6/2006 at 22:03
I can hear up to 20,000 on some really old sony headphones that came with my cd player in 1996. :D
Phydeaux on 15/6/2006 at 01:16
Quote Posted by Hier
A buddy of mine has a weird hearing disorder that affects sound within a certain frequency range that's usually in the middle of the range most humans can hear. It's very strange because he can hear sound on either side of the range just fine. I suppose it's the auditory equivalent of being colourblind.
Anyway, the amusing part is that it's the frequency range that encompasses most female voices. The doctor told him he should consider himself lucky. :D
Sounds like a Monty Python sketch.
I would like to report a burglery!