The development of the FFT algorithm for computing the DFT is one of the primary reasons that digital signal processing (DSP) is so common today. This lab provides a brief introduction to the DFT and FFT. The DFT and FFT are discussed in Chapter 5 of the Lathi text.
x = auread('hw1data.au');
sound(x)
X = fft(x);
The sampling rate for this signal is 8192 samples per second. You can plot the FFT magnitude versus Hertz with the MATLAB commands given below. Make sure that you understand what these commands are doing - you will have some homework exercises next week that will use MATLAB and the FFT.
Fs = 8192;
N = length(X);
f = (0:N-1)'/N*Fs;
plot(f, abs(X))
Which frequency (in hertz) appears to be dominant? Do harmonics appear to be present? Can you guess what produced this sound?
Thank you.