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 Loss in dB per meter 
Name: N/A
Status: N/A
Age: N/A
Location: N/A
Country: N/A
Date: N/A
Question:
Taking into consideration the effect of the inverse square law on the propagation of sound waves in free air, how would you calculate the loss in dB per meter? For example, a sound source, a one K tone burst produces a level of 90 dB at 3ft. away from the source. What would be the level in dB at 100yds? If possible, establish a norm for temperature and relative humidity. Just a musician trying to design an outdoor sound system. Thanks!


Replies:
The direct answer to your question is that in terms of power, dB(100 yds) = dB(3 ft)-200, assuming a pure inverse r-squared law.

Jack L. Uretsky


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