Don't Believe Everything You See... Hear... Wait, What?

Watch the following 4 second video and pay close attention to the man's mouth.

http://youtu.be/HYgIiGaJ9_g

http://youtu.be/HYgIiGaJ9_g

You heard Dah Dah... Dah Dah... Dah Dah... right?

Play it again, but this time turn your head away from the screen and just listen. What did you hear?

You heard Bah Bah... Bah Bah... Bah Bah... right?

How can this be? Without going too deep into science, let's first accept the fact that this happens (well, to most people). The theory behind it is that your hearing is actually dependent upon what you see and not solely on what you hear. This is called an auditory illusion - similar to an optical illusion except the illusion is centered on what you hear. This particular illusion is called the McGurk effect. It was discovered - completely by accident - in 1976 by Harry McGurk.

1976 wasn't too long ago in the grand scheme of things. This means that mankind has been unknowingly sitting on this for thousands of years and it was right in front our faces the entire time. It makes one think: How many other illusions do we experience continuously but don't know it? This accentuates the point that you should listen to your other senses even if it isn't obvious at the time.