Bone conduction is the transmission of sound through vibrations in the bones of the skull that stimulate the cochlea in the inner ear, without relying on the usual sound-transmission pathway through the outer ear, eardrum, and middle-ear ossicles.
When the skull vibrates, several mechanisms contribute to stimulation of the cochlea. The resulting mechanical activity is detected by specialized sensory cells, which convert it into electrical signals transmitted through the auditory nerve to the brain, where the sound is perceived.
Bone conduction occurs naturally when a person hears their own voice. It also has practical applications in hearing assessment and in bone-conduction hearing devices, which transmit vibrations through the skull to stimulate the cochlea. Such devices can benefit some people with conductive hearing loss or certain conditions affecting the outer or middle ear, provided their inner-ear hearing function is sufficient.
QUICK FACT
Bone conduction helps explain why a person’s own voice can sound different in a recording. When speaking, a person hears a combination of sound transmitted through the air and vibrations conducted through the body. A recording captures the airborne sound rather than the same combination experienced by the speaker.
COMMONLY CONFUSED WITH
- Air conduction: Sound travels through the air to the eardrum, then through the ossicles to the inner ear.
- Conductive hearing loss: Hearing loss caused by impaired sound transmission through the outer or middle ear. Comparing air- and bone-conduction hearing thresholds can help identify this type of impairment.
SEE ALSO
- Outer Ear
- Middle Ear
- Inner Ear
- Cochlea
- Air Conduction
- Conductive Hearing Loss
- Sensorineural Hearing Loss