FREE Subscription
The World’s Most Popular Natural Health Newsletter   
 
 
POSTED BY
November 03 2007
62,014 Views

BROWSE BY CATEGORY

Amazing Audio Illusion!

(Listen to this video: 12 seconds x 2)

This is a recording of Shepard’s ascending tones, also called Shepard’s Paradox. When you listen to the recording two or more times in quick succession, the pairs of chords sound as if they’re advancing up the scale with each successive play.  

Is it real, or are your ears deceiving you? 

Auditory illusions are illusions of hearing -- the sound equivalent of an optical illusion where your eyes deceive you. Depending on the illusion created, you may hear sounds that are not present in the recording, or other “impossible” sounds. These illusions highlight areas where your ear and brain differ from perfect audio receptors, for better or worse. 

In Shepard’s Paradox, the starting pair of chords is in fact the same as the finishing pair, creating an auditory illusion that the pitch gets higher with each play. If you looped this sample seamlessly, it should be impossible to tell where the sample begins and where it ends. 

Enjoying life, having fun, and being struck by awe when faced by fascinating new things is an important part of creating a life of good health. So, if you’re up for more auditory puzzles, try out BoingBoing’s other recordings as well, which include Falling Bells, and Quickening Beat, or for other types of mind-boggling illusions, check out some of my related articles below.  

Sources:


Did you find this article interesting?  Interesting Not Useful
Community Comments ( 16 )
Comment on this Article
  
  
Bob2
[ Joined on 06/06 ] [ Posted on October 17, 2007 ]
10 Points        
   
 
Savvy User
Well, I guess it's supposed to create an illusion of higher pitches on the next listen, even though it's always the same audio.

Being a musician, this has zero personal effect, as this is simply an ascending chromatic pattern from B to B, which sounds exactly the same on each replay.  Maybe one needs to be left-eared?  :)

 [ Reply ]
Mercola
  
Patty D
[ Joined on 06/07 ]  [ Posted on October 17, 2007]
3 Points        
   
Savvy User
  Mercola
Thanks Bob, that's what  I was picking up too, that it was an ascending octave and nothing special.
  
  
TomRobinson
[ Joined on 06/06 ] [ Posted on November 3, 2007 ]
5 Points        
   
 
Novice User

The audio is not an ascending chromatic scale, even though that's what it sounds like. Each note is a specific combination of several frequencies, and the first note and the last note are exactly the same.

 [ Reply ]
  
  
samurai
[ Joined on 04/07 ] [ Posted on October 16, 2007 ]
5 Points        
   
 
Savvy User
I don't get it.  Maybe someone can help me out here?  (too many Pepsi Colas in my past life or something....)
 [ Reply ]
Mercola
  
Patty D
[ Joined on 06/07 ]  [ Posted on October 16, 2007]
6 Points        
   
Savvy User
  Mercola
I don't see what's so magical about it either samurai.  As I sing, I sang the notes too to see if, in reality they were going up the scale and they are, so I'm missing what the "illusion" or mind trick is.
Mercola
  
Russ Bianchi
[ Joined on 09/06 ]  [ Posted on October 16, 2007]
7 Points        
   
Savvy User
  Mercola
Well that makes three os us not 'getting it'..unless and these are GUESSES, the musical notes are the same at different frequencies/inflections/volumes and/or scales?

This has nothing to do with too many Pepsi's Samurai, that would adversely effect body weight, predisposition to hypoglycemia and cardio vascular issues.

Uncle Russ
Mercola
  
samurai
[ Joined on 04/07 ]  [ Posted on October 17, 2007]
3 Points        
   
Savvy User
  Mercola
I don't think I am tone deaf-- I hope not!      :)
  
  
jimbobg
[ Joined on 11/07 ] [ Posted on November 5, 2007 ]
       
   
 
Novice User

This is an easy one to understand, but quite difficult for me to explain. Basically, it's using octaves (doubles) of sine waves (pure tones) to create a full sound. When the sound gets to the next octave, it will be double what it was, but your ears can't distinguish that because they only have a range between 20Hz and 20,000Hz.

Example:

Starting sound contains pure tones of:

55Hz, 110Hz, 220Hz, 440Hz, 880Hz, 1760Hz, 3520Hz, 7040Hz, 14080Hz

Once it has gone through all musical notes and come to its next octave, it will contain:

110Hz, 220Hz, 440Hz, 880Hz, 1760Hz, 3520Hz, 7040Hz, 14080Hz, 28160Hz

Your ears will hear this as being the same as the original, even though it's twice the frequency. The only difference is the addition of the 28160Hz tone and the lack of the 55Hz tone. Your ears can't hear the 28160Hz tone, and can't really tell that the 55Hz tone has disappeared, so it assumes that the sound is exactly the same, because all the other frequencies are still resident in the sound.

I hope as a sound engineer and not a teacher, that I've been able to explain this clearly so everyone can understand ;)

 [ Reply ]
  
  
Mad
[ Joined on 06/07 ] [ Posted on November 4, 2007 ]
       
   
 
Novice User

Is this another left/right brain conundrum? I get both effects simultaneously, but I can't quite explain how. It's the audio equivalent of the M.C. Escher print of the impossible staircase, where it seems as if people ascend forever, but they are climbing the same series of steps over and over.

I think I would make a really lousy trial witness.

 [ Reply ]
  
  
illusions
[ Joined on 10/07 ] [ Posted on November 4, 2007 ]
       
   
 
Novice User

When repeated, forms a variation of Bach‘s ‘Endless Rising Canon‘, a technique common in popular music! Enjoy in good health!

 [ Reply ]
  
  
"David"
[ Joined on 08/06 ] [ Posted on November 3, 2007 ]
       
   
 
Savvy User

I see a lot of comments on You Tube. such as "wow, Thats cool", etc. etc.

...Are these the same people/kids who are consuming vast quantites of junk food, cocacola, et al do you think?!!

...... Same kind of susceptability to illusion perhaps :)

 [ Reply ]
  
  
"David"
[ Joined on 08/06 ] [ Posted on November 3, 2007 ]
       
   
 
Savvy User

...Nice piece of humour Islander! :0)

 [ Reply ]
  
  
Russ Bianchi
[ Joined on 09/06 ] [ Posted on October 16, 2007 ]
       
   
 
Savvy User
Dopler Effect?
 [ Reply ]

 
Truste
 
Mercola