How does rarefraction affects the frequency of waves ?

Answer 1

Rarefraction affecting frequency? It does not affect frequency, it affects very temporarily the density of air as air particles move apart, but immediately compress.

Answer 2

http://en.wikipedia.org/wiki/Rarefaction

Answer 3

Rarefactions occur at intervals of one wavelength, in the case of sound waves. They are part of the wave phenomenon itself and do not affect the frequency.