Refraction of Sound

On 13 Jul, 22:53, HardySpicer <gyansor...@gmail.com> wrote:

> Yes it was more the sound at the output I was interested in than in
> the medium itself.
> You have answered my question I think. If I take a loudspeaker and
> attatch it to a cavity filled with a gas I can shift the frequencies
> right?

It depends on the sound you use to excite the cavity.

If the loudspeaker emits a steady-state tone, then no,
you don't see any changes in frequency in the cavity.
The gas will vibrate at the same frequency as the
steady-state tone.

If the loudspeaker emits impulses, then the cavity
will resonate at a different frequency than it would
if it was filled with air. This is the reason why
people get 'Mickey Mouse voices' when they breathe
helium. The voice cords emit impulses at the same
rate as in air, but the resonance in the vocal tract
occurs at a different frequency because the gas
has different compressibility and density than air.

Rune