Sound recording has been a consumer technology for so long now that it is ubiquitous, reaching for a mobile device and firing up an app takes only an instant. Anyone who takes an interest in audio recording further will find that while it’s relatively straightforward to make simple recordings. But, as those among you who have fashioned a pair of Shure SM58s into an X configuration with gaffer tape will know, it can be challenging to create a stereo image when recording outside the studio. In the quest to perfect this, [Kevin Loughin] has created a binaural microphone, which simulates a human head with microphones placed as ears to produce ambient recordings with an almost-immersive stereo image.
Commercial binaural microphones can cost thousands of dollars, but this one opts for a more budget design using an off-the-shelf mannequin head sold for hairdressers. It’s filled with high-density foam, and in its ears [Kevin] placed 3D-printed ear canals with electret microphone capsules. On the back goes a battery and a box for the bias circuitry.
The results as you can hear in the video below the break are impressive, certainly so for the cost. It’s not the first such microphone we’ve shown you, compare it with one using a foam-only head.
Got a vinyl binaural recording years ago. With good cans (didn’t work with speakers), the illusion of “being there” was stunning. Until you turned your head. When you did that, the sound field spun around with your head instead of staying right where it was. Some voice to your left would say something and you’d reflexively turn your head in that direction, but the voice would move to still be on your left. Very disconcerting, and not at all pleasant.
That doesn’t make sense. If you turn your head, the headphones turn with it, so it’s the same.
The whole point is to emulate being there, so you record and send each channel straight to the corresoonding ear. If you used speakers, then yes the image stays the same but you shift the perspective
Recording has speaker at approximately 10 meters away and 30 degrees to the right. With head phones on, eyes closed, that’s exactly where it sounds like the speaker is.
But I’m a human, not a bot. So, when this person talks, I turn my head to hear a bit better. But the recording doesn’t know I’m going to do that, the audio player doesn’t have a way to deal with that, and the headphones are holding on to my head correctly. So, I turn my head to face this speaker, and they are still 30 degrees off to the right.
Yes but there are solution for PC, that they can track user head and adjust the position of the sound :)
But it probably work for something like games, not static record…
That sounds like an awesome effect. Now make it say something creepy.
I did some experiments with this, using my own head instead of a dummy. I made some recordings when I lived in Japan and a few in my back yard in rural Missouri. Links to the recordings are located here: https://drmrehorst.blogspot.com/2018/10/binaural-recordings.html
Wow, I just read your comment after leaving mine. We both used our own head a dummy. I’m checking out your link now!
Cool recordings. My “head-as-dummy” recording is here: https://soundcloud.com/jerry-sneede/sdl, a little journey rollerblading around the New Orleans French Quarter in 2001(or 2002?) with microphones in my ears, recorded to a small stereo cassette recorder. It starts off kind of boring, but gets better with the introduction of “Jabberwocky.”
The Primo EM172 mic cartridges are very low noise so good for recording quiet stuff like some bugs and animals. They cost about $10 each the last time I looked and are much better than the cheapo Panasonic cartridges people often use. A simple modification allows for improvement of large signal handling. See: nhttps://www.linkwitzlab.com/sys_test.htm
The Panasonic electrets and imitators do a surprisingly good job, but yeah the Primo capsules are noticeably quieter.
btw, the current model is EM272; the 172s are discontinued.
I first built panasonic electrets into cheap walkman-style headphones. Great stealth rig using a minidisc recorder. I’m now using 2 Primo EM172s in a homebuilt clone of the Crown SASS baffle (a sort of dummy-head rig) with great results – recording with a ZOOM H4n Pro.
It’s my favourite rig for recording natural soundscapes, nature etc.
Perhaps I am wrong, but I think, while a nice build, it’s conceptually wrong IMHO.
Even if it was possible to record sound from within a real human her canal (let alone a mannequin),
this setup would be recording what “arrives” to the timpane mebrane.
Once reproduced, it will again have to traverse the hear canal and reach again the timpane membrane, thus having a double distorsion/filtering caused by the ear canal.
A more clever setup would be to put two semi-directional microphones on the upper extremities of a T as wide as a human head; this will record the sound before it enters the ear canal and when reproduced it will sound as natural as a real one.
There’s been a lot of research into binaural recording and what you propose does not actually reproduce the sound correctly because the left “ear” would still record sound coming from the right and vice-versa since there is nothing to block or dampen the sound. A simple baffle would improve this, but the human head does “weird” things to sound waves as they come around (and through) the head and skull. Recording at the inner edge of the ear-canal and then playing back using headphones means that the distortion from the ear itself is not really “added” again during playback as the sound is coming straight into the ear canal from the headphone drivers so sound recorded this way does sound natural. To really reproduce the directional feeling/quality of the sound you need something more or less human head shaped between the microphones
It’s not like most people these days have a whole lot more to separate their ears.
Just hollow it out, throw couple nuts in there and shake it so they clink together every now and then. Perfect reproduction for most of the masses!
Ambisonics can record the more or less complete sperical soundfield with a ambisonics microphone.
https://en.wikipedia.org/wiki/Ambisonics makes it possible to decode the recorded sound for listening over various speaker configurations from mono, stereo, 5.1, 7.1 or Headphones.
For headphone listening it is possible to have a headtracker and turn your head and the sound will not move with your head.
I have a simple design of a headtracker buit with a 8266 D1 mini and a IMU module GY-055 that sends directonal info over USB or WiFi on http://www.ohti.xyz
…very cool! Thanks for publishing that!
Hmm.. where does this look familiar from?
Got it!
https://worldradiohistory.com/Archive-Hobbyist-Specials/Electronics-Hobbyist-1989.pdf
Build a Binaural Mikeset… Thomas Krebiel p.145
That’s magazine page 145, not pdf page 145
Hah. I have that very issue somewhere. :-)
And if that doesn’t work, there’s the “Bionic Ear” on page 11.
Binaural recording was a thing in the fifties, then faded, and got a reprise in the seventies or eighties. One of the Japanese companies, I’m thinking JVC, sold headphones with built in microphones. Maybe not as good as a foam head, but remember, the head between the ears is an important component. And easier than setting up a foam head.
Livescribe pens used to come with ear buds that had built in mic capsules to allow recording lectures. That pen and the recordings got me through dental school.
Since 1881! People were able to discern the position of singers and instruments in the orchestra. We knew how to do this right from the beginning but all the studio engineers have been muck-mixing it up with such abominations as the center channel speaker and all multi-mono tracks they call stereo. I grew up hearing what I called tri-phonic, left, center, right! The first stereo boards didn’t have even pan pots.
I have two dumkoffs but haven’t used them lately. Now that I have a high def camera with stereo audio in I need to get active again though there is very little live music here anymore. I have VHS hifi and even a stereo edge track VHS tape that need transferred as well as that night in a videogame place in the mall in back in 1981.
When I was in New Orleans in 2001 I really liked the sound I heard when moving from place to place in the French Quarter on my rollerblades – the way one live music sound would fade out and another fade in, like nature’s mixing board. I had recently learned about binaural recordings, and had the idea to make one using my head as the dummy head. I was really interested in what made something sound like it was behind the listener, and wondered if that could be achieved like this.
I was pretty broke, so I couldn’t get any fancy equipment – I bought a small cheap stereo lav mic from Radio Shack and a little stereo cassette recorder, the kind that takes the little cassettes. I was able to get the little mic in my ear canal – the wire to it folded over the mic, and the mic sat in my ear business end out. Now I could rollerblade around recording in stereo and it just looked like I was wearing earphones.
What I recorded was far from a quality binaural recording, and there’s a lot of tape noise (of course), but I think I captured a sweet moment in time in the French Quarter – the music, the young woman I was seeing, and it takes you on a bit of a journey.
It’s called A Sweet Devious Look, and you can hear it if you’d like: https://soundcloud.com/jerry-sneede/sdl.
Headphones required (of course).