Rhythms and the Vestibular System
I am reading tons about sound and rhythm, and their affect on the auditory and vestibular systems. Currently, I am reading the 2001 version of Listening with the Whole Body by Sheila Frick and Colleen Hacker. (The new version is due in January!)
I didn't realize that the vestibular system (as opposed to the auditory system) picks up and utilizes sound frequencies in the 16-50 Hz. These low sounds are primal and input to the autonomic system as input to our fight/flight motor algorithms. Why? The sounds might come from thunder or from a predator and we may need to run.
Of course, this is not always the case, since low sounds can come from percussive instruments which the body can enjoy. The sensation of structured rhythm can be very organizing and calming. It is a useful tool in sensory-based interventions. My favorite rhythm CD for use with clients is Sacred Earth Drums by David and Steve Gordon.
A little more from the book: low sounds are multi-directional. They permeate the background. It's hard to tell where they come from (like thunder, for example). High sounds are uni-directional. They move to the foreground with very specific information about where they are. The auditory system can locate low sounds in the range of 500 to 1500 Hz, as well as mid-range and high frequency sounds.
1. Frick, S. M., and Hacker, C. (2001). Listening with the Whole Body. Vital Links, Madison, WI.