I have two xxx.wav input files recorded for 30 seconds in noise lab at different conditions with fs 44,100 need to plot normalized frequency Vs dB in one plot
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Nega Ejjigu
on 4 Sep 2021
Commented: Nega Ejjigu
on 5 Sep 2021
I have two .wav input files recorded for 30 seconds with fs 44,100 each . I want a matlab code for frequency analysis plot in one panel to compare two wav file inputs
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Accepted Answer
Walter Roberson
on 4 Sep 2021
Read the files. Isolate a single channel on each. If they are different frequencies, resample to a common frequency. If one is shorter than the other, truncate the longer. Subtract the mean of each signal from the signal.
Now fft each signal. plot() the real() or imag() or abs() of the first result. Use "hold on" . plot() the real() or imag() or abs() of the second result. Label the plot.
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Walter Roberson
on 5 Sep 2021
[sig1, Fs] = audioread('s.wav');
[sig2, Fs2] = audioread('u.wav');
assert(Fs == Fs2); %sample rate must be same
assert(size(sig1,2) == 1 && size(sig2,2) == 1); %single channel only supported
minlen = min(length(sig1), length(sig2));
sig1 = sig1(1:minlen);
sig2 = sig2(1:minlen);
sig1 = sig1 - mean(sig1);
sig2 = sig2 - mean(sig2);
ff1 = fftshift(fft(sig1));
ff2 = fftshift(fft(sig2));
db1 = mag2db(ff1);
db2 = mag2db(ff2);
x = linspace(-Fs/2, Fs/2, length(db1));
bnd = 1000*floor(Fs/2000);
plot(x, real(db1), 'displayname', 's');
hold on
plot(x, real(db2), 'displayname', 'u');
hold off
xticks(-bnd:1000:bnd);
xlabel('Hz'); ylabel('dB')
legend show
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