function sampling_lab2 % SAMPLING_LAB2 Recreates the results of the SAMPLING lab % sampling_lab2 % % Text here % % x: Variables here % ------- sampling_lab2.m ---------------------------------- % Marios Athineos, marios@ee.columbia.edu % http://www.ee.columbia.edu/~marios/ % Copyright (c) 2003 by Columbia University. % All rights reserved. % ---------------------------------------------------------- % Load the music sample and its sampling frequency [m,fs] = wavread('neneh32.wav'); % Select a small part of it m = m(110000:230000); % Listen to it soundsc(m,fs); % Look at the time signal time_plot(m,fs); % Look at the spectrum figure; subplot(311); freq_plot(m,fs); % ---------------------------------------------------------- % Now resample it without antialiasing filter %(sampling frequency is 4000 Hz, aliasing occurs) newfs = 4000; md1 = sampleit2(m,fs,newfs,0); % Listen to it soundsc(md1,newfs); % Look at the spectrum subplot(312); freq_plot(md1,fs,newfs); % ---------------------------------------------------------- % Lets try to resample it with an antialiasing filter md2 = sampleit2(m,fs,newfs,1); % Listen to it soundsc(md2,newfs); % Look at the spectrum subplot(313); freq_plot(md2,fs,newfs); % ---------------------------------------------------------- % Listen to the difference soundsc(md1 - md2,newfs); % ---------------------------------------------------------- % Listen to the scaling property soundsc(m,fs/2); soundsc(m,fs*2);