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a beginner's guide to
binaural logo

by Ryan Olszewski

Binaural - (of sound) recorded through two separate microphones and transmitted through two separate channels to produce a stereophonic effect. (From Webster's College Dictionary)
Binaural recording is basically just one technique out of many to do a stereo recording. It was designed to more accurately record a stereo source, as a human would hear it.

The difference between how we hear and how microphones hear are very different. We have a semi solid chunk of mass between our ears (our head) that will cause you to hear different than two microphones set up in the same way. This is what separates any other stereo micing technique. In the studio, when a band is being recorded, there are "usually" mono sources and stereo sources. A vocal is usually recorded as a mono instrument, same as bass. A piano is usually recorded as a stereo source because it is a larger instrument, and when we stand right in front of it we can perceive that the low notes are coming from one side and the high notes are coming from the other side. Drums on the other hand are usually recorded as both mono and stereo. Each drum is usually miced up individually and recorded this way, but there is usually a stereo recording done of the whole drum kit, which records the cymbals, and gives the overall feel of the kit. These are all mixed together down to what you hear when you listen to a cd. Every mono instrument can be placed in the final stereo mix wherever the engineer wants it to be.

Binaural recordings are rarely used to record music in the studio for a few reasons. First, they are recorded as two completely discreet audio channels, and they are meant to be listened to as two discreet audio channels. Yes, this means headphones. If you listen to it on your normal stereo speakers, you will hear it just fine, but you won't get the full effect of the recording. The sound from each speaker will get mixed together some during the travel to your ears. With headphones they are kept completely separate and you will get an amazing 3d image. Secondly, usually binaural recordings are used to record larger performances such as a concert or a classical recording, or for nature recordings, where everything will all be recorded at once, no overdubbing. Although this doesn't mean that you have to use it for these purposes.

In a typical stereo micing set up, you usually space or angle your microphones to fit the stereo image that you want. The signal from each microphone goes to a separate track on tape and these tracks are panned left and right accordingly. If a sound is closer to one microphone, it will be louder in that mic and softer in the other; therefore it will sound like it is coming from the proper side when played back. This will sound great if done properly, but it still won't sound like you are standing in the room with the instrument. This is because humans have a brain attached to their ears to decipher the information, which gives us perception of depth, distance, and position of a sound and where our own bodies are in a room. Without our head being in the way we wouldn't be able to do this. (LOL)

We hear a sound from our left side louder in the left ear, and softer in the left because our head is in the way, and because our right ear is aimed more in the other direction. But that is only part of it; we also calculate time difference in our head. Since it takes sound time to travel, the longer the time difference between hearing something in your left ear and your right ear, the further left it is. We can also perceive sound coming from up and down. This is done by us hearing different reflections from our pinna (outer ears). They aren't just for catching the sound !!! Every single feature of a persons face can change how a person perceives a sound, from hair, to facial structure, to how thick your head is. (LOL)

This is why the Kunstkopf head was designed. "Kunstkopf" is a German word meaning "art head". The head is made out of material to simulate an average head. Bone structure, and skin are all taken into consideration, and most of all, the design of the outer ear. Then inside the ears, there is placed an omni directional microphone. This will pick up sound evenly from all 360 degrees around it, just like our eardrums. This leaves the Kunstkopf head to alter the sound to simulate how we hear, by doing all of the things that our head does. This is why it produces such a realistic representation of the sound that was actually recorded.

I don't truly know all that much about Tchad Blake, but this is what I have gathered over time. Tchad Blake seems to be a master of binaural recordings. He has done many hours of binaural recordings. He has incorporated binaural recordings into album tracks, and he has done complete albums binaurally. He doesn't stop at just plainly setting up a head on the floor, in a space that gives tonal balance of the room and instrument, he breaks the norm. Tchad plays with the characteristics of binaural recordings. For example, he has set up the head, with tubes connected to the ears so that they are isolated from sound, except what comes from the far end of the tubes. The tubes are put together facing whatever it is that you record. This way, if something moves left or right from the center of the tube openings, it can move drastically in the stereo image that you hear as the end result. (There is a picture of this at that is what the freaky picture with the head and the tubes is !!)

I have also been told that he has used several techniques to get processed sounds naturally instead of using electronic equipment. Such as muffling a mic with something, all the way to putting a mic in a garbage can (you can picture the resulting sound, if not stick your head in a garbage can and listen, lol) You can hear his awesome style of creation on stuff from Soul Coughing to Sheryl Crow. Listening to stuff he has worked on only makes me wonder what he will do with a band like Pearl Jam. Surely it will be great. I'm actually hoping for one song, whether it is a b-side or not, to be a live binaural recording, with the head stuck in the middle of a room and the whole band placed in the room to mix it. (Tchad has since updated his web site to state that two songs on the album will be fully binaural. --editor's note). We could get some guitars behind us and so on…the possibilities are basically endless.

Ryan Olszewski is a Pearl Jam fan and aspiring audio engineer from Vancouver, BC. He has studied at CDIS (The Center for Digital Imaging and Sound) in Burnaby, BC, where in a couple of months will he have completed the Recording Arts Masters Program. He plans to work in the music industry as a freelance engineer/producer, as well as audio post-production for television and film.

© 2000 Ryan Olszewski