Using frequencies in sound can help in meditation, either though this alters your brain state, it causes you to relax and tap into the brain state that causes dreams or emotions.

When using the sound healing technique you can delve into you own psychological drama, this may cause some issues in your life that you may not be conscious in your life.

The deeper you go the more you learn about yourself and others, you start to begin to realize that nothing matters and every detail is important, or the way round, depending on your wiring.

Sound healing is said also to be used to rewire ones brain, Tom Kenyon has a system to use to join the hemispheres of you brain, left and right together in harmony, it seemed to work for me but I am a spiritualist rather than a scientist.

Sound healing is useful in many ways through MP3 CDS, Tibetan bowls and bells, drums, chanting or any modern instrument, the intent is to heal or relax.

Here is a link to my friend's website. She creates binaural beat sound meditations for relaxation, healing etc.
Wonderfully soothing & calming. Very well priced her products are compared to other similar products which do the same thing but cost hundreds of dollars sometimes.

Unison Therapy - beyond meditation