posted by andrea .
a wave front has the form of a ?
There could be a number of terms that apply.
An isotropic wavefront has the form of an expanding sphere.
A planar wave has the form of a plane.
I went to www.google.com and searched for sound wave front, and here are two of the results:
Strong acousto-optic diffraction by a curved-sound wave front (A) Strong acousto-optic diffraction by a curved-sound wave front (A). Authors: Korpel, Adrianus; Pieper, R. J.. Publication: J. Opt. Soc. Am. A, vol. ...
Sound Wave Solutions If the sound is emitted equally in all directions from the source, a spherical wavefront is formed. Even if it is not emitted equally in all directions, ...
You can find more information if you search for it.