Subject: Fw: "El Cheapo" dummy heads? From: Peter Lennox <peter(at)LENNOX01.FREESERVE.CO.UK> Date: Fri, 6 Jul 2001 09:39:06 +0100----- Original Message ----- From: "Peter Lennox" <peter(at)lennox01.freeserve.co.uk> To: "Peter Marvit" <marvit(at)NEU.EDU> Sent: 06 July 2001 09:11 Subject: Re: "El Cheapo" dummy heads? > Styrofoam rings terribly at certain excitory frequencies. Perhaps dipping > the head in carpet glue (rubberised-type) might work, or candlewax. This > deals slighlty better with the size and surface problems as well. > But all these approaches with dummy heads and pinnae presume headphone or > stereo dipole (with cross-talk cancellation) listening. In those > circumstances, the spatial effect carried by just two signal channels would > be incrdibly good, and cocktail party effect. > But, outside the proper listening circumstances, the spatial effect would > collapse, and you'd be back to the original problem (mitigated somewhat by > having used decent mics). > In fact, even the stereo dipole speakers don't really want a pinnae-encoded > feed, so a sphere mic would be best for that, a possible improvement would > come with the use of sphere+two cardioids, but how are they to be > automatically mixed into the two-channel transmission? > Another solution to the original problem, especialy where only one > transmission channel is available, would be to use a pzm-type mic. Although > this still picks up a lot of room, it doesn't sound as 'hollow'. Couple this > with the use of two(or more) decent speakers at the other end, and the > results would be more usable than present-day speakerphones. > The last alternative would be a hypercardioid mic, but the problem here > would be that the user must stay in the pickup area, and face the mic. > Any other solution would have to involve eschewing the speakerphone, and > wearing a headset with a close miked omni.. - maybe bluetooth technology > would make this feasible, or just a cheap(!) radio mic. > Of all these, I would say that the pzm would be the most cost-effective, > whilst the sphere-dipole combination would be the best for utilising > cocktail party, if two channel transmission were available. > cheers > ppl > ----- Original Message ----- > From: "Peter Marvit" <marvit(at)NEU.EDU> > To: <AUDITORY(at)LISTS.MCGILL.CA> > Sent: 05 July 2001 15:03 > Subject: "El Cheapo" dummy heads? > > > > One part of Henrik's very nice response to the speakerphone question got > > me pondering; dummy heads can be quite useful for making binaural > > recordings but are rather expensive. > > > > For various reasons, I have a small collection of styrofoam "heads" > > usually used to display hats or wigs in retail stores. Does anyone have > > any experience using these as a basis for home-made dummy heads? I imagine > > drilling holes and inserting microphones inside. Even more ambitious would > > be to mold pinna and glue them on (or perhaps use some theatrical ears? > > Hmmm, "Spock" ears?). These styrofoam heads are a tad smaller than adult > > humans and the material is obviously of different density than humans > > (with possible exceptions duly noted). > > > > Would they mostly work at a much cheaper cost, nonetheless? > > > > Cheers, > > Peter > > > > > > : Peter Marvit, PhD <marvit(at)neu.edu> > : > > : Northeastern University, Dept. of Speech-Language Pathology and > Audiology : > > : 133 Forsyth Building, Boston, MA 02115-5000 > : > > : phone: 617/373-5198 fax: 617/373-5199 > : > > > > >