Sound

Both.

Type your question into Google and you'll find a wealth of information....

I'm not trying to be cruel here, in fact, i'm trying to be helpful. You could answer your own question in 30 seconds witha simple Google search.

Why would you use google when you can search the engineering web with globalspec?

http://search.globalspec.com/Search?query=sound&show=total

Neither, they are compression/rarifaction.

Then please correct Wikipedia, they seem to have the wrong information that Sound waves are Longitudianl Waves.

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

And the spelling is rarefaction, not rarifaction.

Hmmm. Re: Spelling: "longitudianl"?

In gases only longitudinal.

In solids, longitudinal ( = piston like), transverse or both.

Insufficient context...to answer the question succinctly.

Hints:

1. Is it a trick question?

2. Are you trying to win a wager? or...

3. Trying to prevail in a philosophical or semantics dispute?

4. Other?

Your response will help get your answer.

Sound waves in gases and fluids are longitudinal, and at any point in space the molecules vibrate along a vector perpendicular to the propagation direction.

In solids this depends on the atomic or molecular structure, and in some bones, in special those forming part of the auditory sense of almost all animals, the vibration vector is a complex function of the inner fiber distribution, whereby to transmit or isolate sound.

Jaime Soto

Chile

Hop hop hop, I wanted to say "perpendicular to the propagation WAVEFRONT PLANE"

Sound waves in gases and fluids are longitudinal, and at any point in space the molecules vibrate along a vector perpendicular to the propagation WAVEFRONT PLANE.

In solids this depends on the atomic or molecular structure, and in some bones, in special those forming part of the auditory sense of almost all animals, the vibration vector is a complex function of the inner fiber distribution, whereby to transmit or isolate sound.

Jaime Soto

Chile