this is a video of a talk of a guy stuck in visa-hell. alas, I've been there.
this is for mobile phone ensembles. devices do not know each other's physical position. so performers need not stand in a pre-arranged formation.
They play sounds at each other to measure location. This is a piece in and of itself.
They make pairwise distances and then compute three dimension position from the distances. 1 sample error is 1.5cm error. also, clock issues.
One device hears a message, the other plays sound back. They have an agreed upon delay, so as to duck the clock issue. They have an onsent detector that does fast and slow envelopes, like yesterday's presentations. The measurements were repeatable and accurate.
They do vector matrixes to guess positions.
The ping pong notes are going along a midi score. There are some ways to recover failure.
There is geometric ambiguity. Background noise creates a problem. As do reflections. They are wondering how to solve this without restorting to harsh noise, but I say embrace it. Why not hardcore mobile phone ensembles?
Will the system work with sounds outside of the human range of hearing?
Probably not with iPhones or iPods, but it could work.
Why use the audio clock instead of the CPU clock?
the audio clock is much more reliable because its runs in real time. The CPU clock has a lot of jitter.