DIY binaural dummy head

The fall semester has come to a close and I’ve somehow escaped unscathed as far grades go (…nerves are another matter).

I have also honed in on a research topic - which I hope to get a chance to discuss in greater detail later - for now, let’s call it what I called it in my official thesis proposal document: Perceptual Effects of Cross-Contextualized Soundscapes within the Built Environment. - basically I plan to create a sound installation around a green wall and analyze its perceptual effects.

Before this topic solidified, it was more general and something about recording forest sounds.  I was anticipating having to do a lot of field recordings of forests - which would have been fun, but after having done some preliminary outings it became apparent that I will have to be very careful about the amount of stuff I take on what would essentially be hikes, since stuff and weight can add up pretty quickly (recorders, tripods, cameras, laptop, microphones, speakers…).

Some metrics require a binaural impulse response, which would typically necessitate a professionally designed binaural dummy head.  Needless to say, the recordings I was planning on doing could not afford this kind of resource - neither economically, nor in space or weight.  I thought I could do better with something homemade.

I started here:

Once I had these two lovely heads, I picked the one whose ears I would have to drill holes in:

using a pair of radioshack electret microphones, I pulled them through her ears: 

At this point, the anthropomorphizing became impossible to avoid and it occurred to me that her name is probably Jenny.

Some more photos:

…with the mic shoved all the way into Jenny’s ear.

…me listening to what Jenny hears.  You can tell by our equally disheveled hairdos that it’s getting late in the night.

Doing some quick listening tests: she localizes fairly well in the horizontal plane, and less so (not at all really) in the median plane (the up-down direction).  Lack of shoulders might be a substantial problem, as well as the absence of a real ear canal - the pinna alone seems to do little to help in this regard.

In any case, Jenny provides me with an easy to implement way of getting a binaural recording of a remote space (even if not entirely accurate - a disclaimer I am willing to apply).  The mics are wired to run off of plug-in power on any portable recording device like my olympus - so she is completely portable.  Also, she looks great mounted on a tripod:

Recordings are forthcoming.  Stay tuned!!

  1. spacesound posted this