Natural Science Forum / Physics / Acoustics / April 2004

Hi there,
I'm doing an RT60 calculation of a room at different frequencies. I'm
using 1/3 octave noise for frequencies smaller than 512 Hz and octave
noise for highest frequencies. I've recorded all the reverbs and now I'm
 feeding matlab for the analysys. I've some question:
1) Could I bandpass the signals (that now are only short reverberations)
 to remove the unwanted noise (the room is not perfectly isolated!) and
if yes could I bandpass It with filters that have the same range of the
original octave or 1/3 octave noise (Example: i've recorded the reverb
of a 512-1024 Hz noise. Before giving it to the RT60 calculation
algorithm could I bandstop frequencies >1024 and <512 safely?)
2) Have you any Matlab function the calculates RT60 from a wav file?
3) Could be the hilbert transform suitable for enveloping purposes?
I'm a beginner, please be patient!
Bye,
Giorgio