Theory of Megaphones and Receiving Horns

Authors

G. W. Stewart, University of IowaFollow
G. R. Butz, University of Iowa

Document Type

Research

Abstract

In 1919, A. G. Webster published a theory of the action of horns used as receivers. Recent development has given an increased interest in the megaphone. Webster's theory may be modified to cover the case of the megaphone, assuming the constancy of the acoustic point impedance of the horn at the source. The result obtained is that the emitted energies at different frequencies are related as are the values of [(ad-bc)/(a-cz₂)]² wherein a, b, c and d, have the values specified in Webster's theory and z2=δa²k² (ki/2π-1/c₀), k being 2π divided by wave length, ρ the density, a the velocity of sound and c₀ the conductivity of the opening.

Publication Date

1924

Journal Title

Proceedings of the Iowa Academy of Science

Volume

31

Issue

1

First Page

381

Last Page

382

Copyright

©1924 Iowa Academy of Science, Inc.

Language

en

File Format

application/pdf

Recommended Citation

Stewart, G. W. and Butz, G. R. (1924) "Theory of Megaphones and Receiving Horns," Proceedings of the Iowa Academy of Science, 31(1), 381-382.
Available at: https://scholarworks.uni.edu/pias/vol31/iss1/129