%In class Exercises for 1-24-2013
%You may use Tuesday's notes for guidance
%1. Load khan.wav and identify the frequency in Hertz
%of the largest DFT coefficient.
%2. Add Gaussian noise to the khan signal, plot the absolute value
%of the DFT coefficients of the noisy signal. Based on this plot choose
%a good cutoff frequency and design a lowpass filter to denoise the signal.
%Plot the magnitudes of the DFT coefficients of the filtered signal.
%3. Similar to the lowpass filter defined in 2, define a high pass filter
%and a band pass filter with cutoff frequencies of your choosing.
%Apply them to the khan signal and plot the magnitudes of the DFT coefficients
%of the resulting filtered signals.