diff -r 9885d7b7aca0 -r 162d64fb861c audio_io.py
--- a/audio_io.py
+++ b/audio_io.py
@@ -57,7 +57,10 @@
 ## Plotting the new signal using pylab/matplotlib
 #################
 
-plt.plot(new_samples)
+# the x axis now shows the time in seconds instead of the sample number
+## using the Numpy function linspace in order to create the time array
+x_axis = np.linspace(0, 0.5, new_samples.size)
+plt.plot(x_axis, new_samples)
 plt.show()
 
 #################