High(very high) frequency sound waves = heat? I had this question in mind and did not quite found the answer on google. If heat is a vibration of particles in matter, and sound is pressure wave moving using particles (causing them to fluctuate), could a very high frequency sound wave raise the temperature of matter which it is travelling in? 
 A: Sound waves can definitely be used for heating of matter. High intensity ultrasound waves are (among other applications) used for internal heating of parts of the human body for medical therapy of a number of conditions. See Therapeutic Ultrasound. The extreme heating of gas bubbles in water by high-intensity ultarsound has also led to the discovery of the baffling phenomenon of sonoluminescence.
A: Technically speaking there is a difference between high frequency sound waves and heat, though they can have similarities.  Heat is typically stochastic vibrations -- random vibrations that nobody can predict.  Sound waves are typically well ordered vibrations, which still have some structure to them.  Accordingly there are ways you can use many sound waves which you cannot use heat for.
Now quite often high frequency sounds can be absorbed by a medium, which really means that they were turned into random vibrations -- heat.  However, we typically think of the sound as something other than heat as long as we can find ways to use its structure.
If you were to think of all the particles of a material as little tiny loudspeakers, and they were all emitting noise (Brownian noise, to be specific), then the connection between sound waves and heat would probably be pretty close to perfect.
