[PD] [OT] gallery installation sound

Georg Holzmann grhPD at gmx.at
Tue Feb 13 18:41:40 CET 2007


>> Usually acoustic measurements are done with impulses, AFAIK.  An  
>> ideal impulse actually has all frequencies in it, so it's useful for  
>> that kind of thing.  Plus it's easy to differentiate between the  
>> initial signal and the room effects just based on time.
> Actually I think, engineers prefer to use frequency sweeps instead of
> pulses nowadays. The problem with pulses is, that they are hard to get
> right: You need a clean pulse and a very silent environment: 

Well, there are also problems with swept sines of course ... ;)

Other methods are e.g.
- with MLS (http://en.wikipedia.org/wiki/Maximum_length_sequence) - I 
think there is also an mls example in the iem_tab library.
-Least Square Error methods (see system identification example in the 
adaptive library)
- with noise (more energy than in a dirac impulse)
- auto-, crosscorrelation methods
- ...


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