Experiment 1 Audio signal processing
Design and implement a system F using MATLAB platform. The input is
0
:[
Integer16]
X
→
¥
. The output is
0
:[
Integer16]
Y
→
¥
.
1. Audio signal analysis
Plot the waveform in time domain and the spectrum in frequency domain
respectively. The following sentence may be useful.
[x,fs,bits] = wavread(‘F:\*\*.wav’); % read the *.wav file
sound(x,fs,bits); %play
n = length (x) ;
%find the length of the signal
X=fft(x,n);
%Fourier transform
subplot(2,1,1);plot(x);title(' waveform of the original signal');
subplot(2,1,2);plot(abs(X));title(' spectrum of the original signal ')
Fig. 1 Example of waveform in time domain and the spectrum in frequency domain
2. Add
noise.
From the spectrum, find the bandwidth of the signal and then determine the
sampling frequency.
Add a 3.8KHz high frequency noise. Plot the time domain waveform and
the frequency domain spectrum respectively, compared with the original signal’s waveform and

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- Spring '14
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