The brain is an amazing thing.  It is so strange how the brain can fill in the blanks with what it sees and hears

 

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Take a listen to these two audio clips.  Listen to the first clip that has been modulated by computer.  See if you can understand the sentence at all.  Then listen to the actual original phrase un-modulated.

After you hear the phrase listen to the modulated one again.  This time you should be able to hear it clear as day.

 

Now listen to this version of the original recording that isn't computer modulated.  After listening to the original, go back and listen to the modulated version to see if you can understand what is being said.  Get ready to be surprised.  The brain works in amazing ways.