Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Infrasound Sources
Name: Marjorie A.
Status: N/A
Age: 18
Location: N/A
Country: N/A
Date: 2/25/2003


Question:
What are the sources of infrasonic sounds?


Replies:
Marjorie,

Here is a start: Elephants, earthquakes, certain sea dwelling whales, and large electric power generating windmills.

Regards,
ProfHoff 568


Dear Marjorie,

Infrasound is simply what we call any sound that is below the threshold of our hearing. Sounds being caused by vibrations, can be produced by anything that is vibrating at a regular frequency. To be infrasound, we could not detect it. Scientist for a long time thought that elephants did not communicate audibly with one another. Some bright guy had an idea to put up microphones and boost the frequency. It was found that elephants communicate in this range. As far as any other sources of infrasounds, I am sure there are plenty. Good luck in your search. The elephants are a starting point at any rate.

Martha Croll


Standing waves in chimneys, wheels of vehicles, vibrations of light poles, vibrations of trees, trains, very slow rotating equipment are a few sources that have been measured.

Samuel P. Bowen
Professor of Physics
Department of Chemistry and Physics
Chicago State University


This depends upon several factors. Are you referring to transverse waves (up and down) or compression waves (back and forth)? The medium through which the sound waves travels is also an important factor. Do you want a continuous source, or just a short wave packet? A pipe (like an organ) that is long enough and wide enough can emit sound waves less than (15-25 cycles/sec) a typical value of the low end cut-off of the human ear. A piston connected to an appropriate magnet carrying an alternating current of the appropriate frequency can also work. I'm sure jet engines, or even propellers produce some low frequency inaudible sound in addition to their typical "roar", but I do not know what the frequency distribution is.

Vince Calder



Click here to return to the Physics Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory