Using sound to assist with meditation, healing and relaxation has been used thousands of years by all cultures. The reason it works is because of resonance, dissonance and entrainment as I mentioned in my last post.
We know that all things vibrate. We also know from the definition of sympathetic resonance that if you tap a tuning fork, another fork with the same frequency will be activated and start vibrating. The vibration of one object causes another object to start vibrating. When I play a recording of a singing bowl loud enough, all the singing bowls in my sound room start to ring. Even though the bowls are all different frequencies, the recording was strong enough to set them all off.
So what does this have to do with you? Imaging parking next to a truck with its diesel engine rumbling (vibrating) in a steady rhythm. How does it feel after a few minutes? You may start to feel tension, anger, frustration or however you respond to strong vibrations that are dissonant to you. Sit next to that truck for a long time and eventually the feeling of dissonance may not feel as uncomfortable, you may actually like it. The truck, having a strong vibration can cause you to sympathetically start resonating or vibrating at the same frequency as the truck. At that point, you and the truck are in resonance.
I am not a truck
That's what will happen if you are not paying attention to the truck. Most people recognize that this rumbling is not comfortable and leave the area. That's an important point. We encounter "good" and bad" vibrations every second of every day and react accordingly. We either stick around if we like it or walk away before it effects us long term. When we are not aware of unhealthy vibrations, we unknowingly begin to take on that same unhealthy frequency. That is how we become ill. Vibrations, not resonant with our natural healthy state, will cause you to become out of balance physically and emotionally if you are not paying attention.
Fortunately, the opposite is also true. The Solar Harmonic set of tuning forks for example create harmonics. These harmonics help you to relax so completely that very often people ease in to that place of silence, also known as a still point. This happens because the tones created by this set are healing, meditative tones. When your body senses this it will begin to vibrate at the same frequencies and as a result, you begin to fall into a silent or meditative state. When the body and mind are at ease, healing naturally takes place.
The effect of Solar Harmonic tuning forks may last a few hours or a few days until some other vibration comes along that gets your attention (stress at work or home, traffic etc.). If you work with the Solar Harmonic on a regular, steady basis, eventually that vibration within you will be stronger than anything else that comes along and you will remain in that calm, relaxed state. It becomes the norm. That's entrainment.
So that's resonance and sympathetic resonance, dissonance, entrainment and how it is directly related to sound therapy and healing in general.