Sound, particularly in the low frequency range, may reach the INNER EAR via the bones in the head rather than from the EARDRUM, this phenomenon being called bone conduction. The normal process via the ear canal is called air conduction. Wearing earplugs results in a greater percentage of the sound heard coming from bone conduction.
Normally only a small fraction of sound is received in this way; however, deaf people whose inner ear still functions normally may be able to hear sound conducted to the ear in this way, for instance by holding between the teeth a wooden rod connected to a vibrating object.
Compare: BASILAR MEMBRANE, CONDUCTIVE HEARING LOSS. See also: BONE CONDUCTION HEARING LEVEL.