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 Percussion Instruments: Sustained versus Damped Sound

Name: Rue
Status: educator
Grade: 6-8
Location: NC
Country: USA
Date: Fall 2011

When studying percussion instruments, students discovered: (a) the sound of metallophone bars (metal bars similar to a vibraphone) is sustained and (b) the sound of xylophone bars (wooden bars) is not sustained. Students wanted to know why the metal bars have a "longer sound" than the wooden bars.


Metal is more elastic than wood. Consider a hard metal rod and a hard wooden rod of the same shape and size. Bend each one a little and the metal rod is more likely to go back to its original shape. For the wooded bar, tiny bits and pieces of the wood structure are damaged every time the bar bends. This uses up the vibration energy quickly.

Dr. Ken Mellendorf Physics Instructor Illinois Central College

Because metals are very solid they transmit sound quickly and efficiently. Wood on the other hand has air pockets and individual fibers that move around and absorb energy very well as sound passes. The wood eats up the energy of the strike in a thing called internal resistance.

Hit one end of a 2X4 and the sound dies out over the length of the wood. Sound can be heard in rail road rails over many miles.

R.W. "Mr. A." Avakian Instructor Arts and Sciences/LRC Oklahoma State Univ. Inst. of Technology

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 (, or at Argonne's Educational Programs

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

Argonne National Laboratory