Sound therapy covers a range of practices using sound — hammered metal bowls, gongs, tuning forks, voice, drum — for relaxation or support. The term spans very different approaches, from group sound baths to individual sessions.
What is physiologically established
Three mechanisms are documented and uncontroversial.
The orienting response, and its extinction
A continuous, slowly evolving sound holds attention without demanding processing. The nervous system, having nothing to analyse, lowers its arousal. The same mechanism operates with rain or surf.
Vagal tone
Low-frequency vibration felt by the body — not only by the ear — accompanies a shift toward parasympathetic tone: slower heart rate, reduced muscle tension, longer exhalation.
Masking
A broad sound masks the environment. In a noisy room, part of a bowl's apparent effect comes from what it makes disappear.
What studies do not show: that particular frequencies heal organs or diseases. Available work uses small samples, weak controls and self-reported measures. It shows genuine relaxation. It shows no curative action.
The 432 Hz myth
The claim that tuning to 432 Hz is "natural" or "in harmony with the universe" circulates widely. It has no basis. A440 is a twentieth-century standardisation convention; pitch has ranged from roughly 400 to 460 Hz across periods and cities. A difference of eight hertz is audible to a trained musician and has no known physiological effect.
What a session involves
You lie down, clothed, covered. The practitioner sounds instruments around you, sometimes placed on the body. Sessions run forty minutes to an hour.
Real precautions: photosensitive or sound-sensitive epilepsy, acute tinnitus, pregnancy for instruments placed on the abdomen, cochlear implants. A practitioner who asks no health questions before beginning is a poor sign.
It is not for everyone
Lying still for an hour in a dark room with strangers is restful for some and gruelling for others. People who cope badly with loss of control, or who have a low threshold for sound, sometimes leave more tense than they arrived.
This is precisely the kind of fit RÉSONANCE measures: tolerance for noise, search for silence and need for withdrawal are among the variables recorded in the chamber — with no question asked.