Perfect Pitch on Superhuman?

I got a funny email this weekend. It’s about taking perfect pitch onto a TV show featuring weird abilities. Here, just read it.


Hi Peter,

My name is _____ and I’m with the FOX television network. We wanted to reach out to you for a new TV competition show called “Superhuman”.

We are seeking people with a variety of skills, for example one of the skills we are focusing on is someone who would be able to hear a coin drop on a surface and name the denomination (dime, nickle, quarter) based on the sound of it landing. We were suggested to look for people with absolute pitch hearing that might be able to distinguish the difference in pitch & tone of the coin falling in a isolated area.

The contestant wouldn’t be competing with anyone with the same skill, just showcasing there own.

The winner of the show will receive a HUGE sum of money.

Here is a link to a clip of the “Superhuman” TV special that aired in January on FOX. It did so well its being turned into a 8 episode series.


and here’s my response, which I had fun researching and writing.

 

Thanks for contacting me about featuring perfect pitch on Superhuman!

It’s a fascinating idea, trying to identify coins by the sound of them dropping, but I don’t think it’s possible for practical purposes because coins are imperfect and too similar.

When a coin strikes a surface, it elicits several sounds, assuming the surface is very rigid and doesn’t dampen the vibrations.
1) the dominant striking sound. This is dependent on variables the combination of the two materials and velocity and angle of striking, so no identification can be done using this.
2) the surface’s vibration. It depends on the surface. A broad metal table might sound a little like a steel drum, but a faux-wood table of a different size will sound like something else.
3) the coin’s vibration. This is where the money is (pun intended).

The coin’s diameter, thickness, material, and cast shape (e.g. Lincoln on a penny, an eagle on some quarters) completely determines its resonant frequencies (where frequency = pitch). There’s generally a very dominant frequency — the lowest one — which would ring the loudest when it’s struck by something and caused to vibrate. Thus, the strategy would be to listen for this fairly quiet and high-pitched ringing before the coin comes to rest on the table and hope that the resonant frequency is distinguishable between different types of coins.
Unfortunately, the resonant frequency of one penny does not match another penny, and a nickel doesn’t match another nickel. It seems there are too many variables in the casting process to make each coin exactly the same as the next. This would be permissible if the frequencies followed distributions that had acceptable margins of differences between each other (e.g. almost no nickels sound like most pennies, almost no pennies sound like most nickels). However, from sample sizes of about 5 of each type of coin, the frequency distributions overlap substantially. Therefore, as far as my ears can tell, the coins’ inherent sounds are indistinguishable.

A quick google search shows that someone wrote a paper on this. Indeed, the dominant frequencies of each type of coin are all grouped around the same range — about 12 to 15 kHz — and have overlapping distributions. And… pennies don’t have a resonant frequency?
https://me363.byu.edu/sites/me363.byu.edu/files/Emerson_Steed_CoinIdentification.pdf

Also, I’m a medical student, and there would be no way I could find the time to fly over and tape a show… sounds like fun though!