Re: Acoustics

[Daniel Arteaga]

Al 21/11/10 16:54, En/na Martin Maxino ha escrit:
> Will anyone please direct me to examples of how to use Octave to analyze
> sound (FFTs, etc.).
>
> It would be greatly appreciated.

For instance, to analyze the spectrum of an audio file:

[audio,fs] = wavread ("audiofile.wav");
n = length(audio);              #Number of samples
t = n/fs;                       #Duration in s
N = floor(n/2);                 
temp = fft(audio,2*n+1);
dc = temp(1);                   
audio_fft = temp(2:n+1);        
freq_vector = linspace(0,fs,2*n+1)(2:n+1);
spectrum_dB = 20*log10(abs(audio_fft));
phase = arg(audio_fft);
figure;
semilogx(freq_vector,spectrum_dB);
figure;
semilogx(freq_vector,phase);