Now an important concept in sound therapy - bone conduction. Bone conduction occurs where the sound is transmitted via the bone rather than the ears; the volume of the sound transmitted through the bone is independent of the volume of the air conducted sound…
…When we speak the sound comes out, with the higher sounds thrown out in a straight line, and lower sounds spread out everywhere. (this is one of the reasons why our voice sounds funny in a tape recorder, higher than we think) At the same time the skill vibrates and transmits sound information directly to the ear and down the spinal column directly into the whole body. Great singers control their voices through bone conduction.
[Dr. Alfred A. Tomatis, considered the father of all the sound programs available today] found in stutters and this is especially true for autistic children that there was a lack of harmony between bone and air conduction, with the latter (bone conduction), always being more sensitive. When we speak we bath ourselves in sound, it is part of our feedback. In other words we incorporate (meaning the body) the sound and Tomatis would say when we have these delays “we cannot incorporate the Word”…
Our self-listening mechanism is largely controlled in how we hear ourselves through bone conduction. We are our own first listeners. As we omit sound it goes out our mouth and returns via our ears but even before that we hear ourselves through bone conduction. Tomatis found that the best singer had excellent perception of their own voices through bone conduction and they were neither hypersensitive or unawares in this type of listening…
(source: Intra-Uterine Listening )