[awordinyourear]

I just posted this yesterday in the sound science sub-forum but I think maybe it was the wrong section, apologies.
 
I just signed up yesterday to this great forum, in the hope that someone might be able to offer some advice. I'm trying to make my first 3D audio recording. I have googled a fair bit but I'm not having much joy. I did read some posts in a much earlier thread on this website. I would have replied there, but it's two years old. I hope it's ok to post this here.
 
  The thread I read from is here:
 
http://www.head-fi.org/forum/thread/293793/how-can-i-create-holophonic-sound
 
I have read loads of really complicated sound set-ups. I should mention that I'm not very technical and so I'm really looking for word on whether I am totally out of my depth on this or if it's achievable with my means. There was one poster in the above thread ('edstrelow') who basically wrote out how I imagine to go about it.
 
  I have two small condenser mics (Karma) which I plan to attach to my ears. I have a model polystyrene head if this first option fails.
  I plan to direct each mic obviously in the same direction as the ear canal, and to run these two mics into a small Zoom H4n I'm using. Then of course I plan to make noises and sounds from varying directions and distances.
  Will this create a 3D recording?
 
  If so, can I just leave each mic's setting as central or do I pan hard left for the left channel, and hard right for the right mic? Or a little of each?
 
  Also, does the head need to stay in the same position throughout the recording, with the objects of sound moving around the head, or does it not matter?
 
  Sorry if these questions are particularly naive, and thanks for any help. 

 

[Sophonax]

I've been playing with trying to build a holophonic recording setup myself -- basically I'm trying to make my own version of a binaural dummy head.  So far I've made some ears out of silicon rubber using lifecasting techniques, and I've got a good pair of small Audio Technica microphones to insert in the ear canals.  I still need to make some kind of head though.  Kind of doing this blind, but I hope the results are good in the end.
 
I don't really see a reason why you shouldn't be able to make a holophonic recording in the manner you described.  I wouldn't expect to get the same kind of results you'd get by using something like a Neumann KU-100, but you could probably get a decent, "3D"-sounding recording with your setup.
 
Your two condenser mics -- are they stereo, or mono?  Do they plug into two different ports on your recorder?  I think if they're stereo, or if you have them plugged into different input ports on the recorder, that you'd probably have to pan the left mic to the far left and the right mic to the far right.  My setup might be different from yours -- I have a pair of mono mics, and they share a common ground and plug into a single port on my recorder, with one mic providing the left channel signal and the other providing the right.
 
Holophonic / binaural recordings can be done in different ways -- most probably leave the head stationary, although I've heard some that move the head.  For example, have you heard any of the Naturespace binaural recordings?  There's one called Riverswim in particular -- I'm not exactly sure how they made the recording, but it sounds as though the head is being moved, to simulate what a listener would hear as they float down a river.  I'd probably leave the head stationary when you make your first recordings, just so you can evaluate if they sound "3D".  Once you've verified that your setup can make decent holophonic recordings, then you can use your imagination as you see fit to make interesting or unique recordings by moving the head in various ways.
 
Another thing to consider: if you plan on attaching the mics to your own head, you have to be careful about making noise during your recordings.  I know that there are some products on the market that have two microphones that you wear like a pair of earbuds, but these can pick up sounds from your head if you do things like swallow or move your jaw around.

 

[awordinyourear]

Hi Sophonax,
 
   Thanks so much for your reply, was beginning to think I'd entered a twilight zone!
 
  Great to hear someone else in a similar situation. Btw, about needing to 'make' a model head... have you considered using polystyrene model heads?
  Actually, you've just posed a new question in my mind. If attaching my mics to my own ears doesn't work and I end up using the dummy head that I have (which doesn't have ears, it's just a polystyrene head) then do I have to do something like 'cup' behind the mics with something to mimic the back of the ears? I hadn't thought of this before, until I see you've gone to pains to cast some ears properly. If I don't actually make ears, do you know of any material I could use to simulate the back of the ear? Presumably small, curved pieces of cardboard or some such won't work? Hmm.
 
  To answer your questions... the two mics I have are Karma Micro silver bullets. I'm actually not sure if they're stereo or mono. Just been googling and all I can find is that these are described as 'omni'. Not sure what that means.
 
  Yes, I intend to plug them into seperate xlr ports on the Zoom H4n. Thanks for the advice. I guess I will first try it without panning, then with a little, then hard panning. All will be trial and error, like everything. Still waiting on an order for another xlr cable so I won't be able to try this out for a few days.
  I now have the task of trying to figure out how to attach these to my ears. Unfortunately, they aren't small enough to fit inside the ear canal (they're about 1.5" long) so do you think I could have the same problem with not having my ears as part of the sound?
 
  Thanks for any help, it's nice to know I'm not alone here with this crazy 'attaching to head' business!!
I'm just listening to those Naturespace binaural recordings. Wow! Thanks! 
 

 

[Sophonax]

Thanks for the suggestion on the polystyrene head -- definitely an option I'll look into.  I was looking into making a hollowed-out wooden head, but it would have been a lot of work.
 
As for the ears, I'm sure they make some kind of difference, but maybe it's not that significant.  By making some casts for my dummy head, I was just hoping to make it as anatomically accurate as possible to try to get the best results, but it may not be necessary at all.  But if you think about it, if you don't have ears on the head, then how do you tell the difference between a sound coming from directly in front and one coming from directly behind?  I think the outer part of the ear may be responsible for filtering high frequency content that comes from behind the head, therefore allowing for better front-to-back imaging.  In any case, it's definitely worth experimenting.
 
Yeah, I think you'll probably end up having to pan your left mic to the far left and the right mic to the far right to get the desired effect.  You want the left mic to be responsible for all the audio in the left channel, and vice-versa for the right mic.
 
As for attaching the microphones to your ears, I really couldn't say if that would be a problem or not.  It's pretty hard to predict how these kinds of things will affect the sound -- the only way to know for sure is to try it out!