Sunday, 14 September 2014

BINAURAL: this is a recording technique that places omni-directional microphones (read the following shirt guide to omni mics here) either side of an acoustic baffle in order to a) represent the pick up pattern of our ears (the baffle there being our head) and / or b) create a stereo recording with a specific sense of sound localisation.

Whilst it is most often done by using the human head, as a technique any 'baffle' can be used and indeed any spacing of the microphones can also be used to play with the effect. For example, one could space the mics to the size of a birds head & whilst we can’t know exactly what another creature (or indeed another human) hears it can be an interesting creative tool to do this. Of course lots of species don’t hear the same range of frequencies as humans so, in my opinion, one should always be careful to understand that when presenting work recorded in this manner.

Because of the way the technique works playback via headphones most accurately reproduces the effect. If played back via speakers the effect is, for example, like having a human head the size of the room / speaker placement.

Certain companies will attempt to sell you 'Binaural microphones' at a considerably higher price than a similar specification pair of omni's, often by placing them in 'in-ear' units to wear like ear-bud headphones. Apart from the issue of cost here it is not at all agreed that using them in this way creates a better binaural effect than simply clipping a pair of normal omni's to a hat, glasses or runners h/phone grips. The reason for this is that, in effect, placing the microphones in the ear canal blocks one side of their pick-up sphere (for those who are perhaps new to microphone pick-up patters, omni's pick up sound from all around the capsule), which to some leaves an audible 'hole' in the sound.

I’ve heard a couple of people mentioning that using them next to your ears will give you 'sort of' binaural but actually it is full, proper binaural- there's a slight difference of opinion amongst recordists as to whether in ear or out of ear works best for binaural but both are fully binaural techniques. As I said there is a difference of opinion but personally (& i'm not alone in thinking this) out of the ear always sounds more natural - with the in-ear design you are blocking some angles of pick up for the mic & with our ears sound from every angle enters our pinar & psychologically we 'fill in' the missing parts between our ears - therefore with in-ear binaural recordings we tend to hear it as hyper-reality & we perceive it as 'effect', which means we don't connect to it in the same way.

(omni directional microphone pick-up pattern)

1 comment:

Unknown said...

Thank you for your excellent description. I have sometimes been playing with different patterns of binaural recordings by having 35-50 cm between them. Some of these recordings have not played too well in mono, but I mean that the distance of the sounds sometimes seems to be more realistic when listening. I have sometimes used the looking-glass-technique, It has the big advantage that I am not disturbed at all, becaus if I am also wearing closed headphones everyone thinks I am now testing a new aid for the blind.:)