The ear, a precise and reliable sensory organ
Often on the alert, the ear is a complex mechanism
The ear consists of 3 parts
 The external ear: the auricle, the auditory canal and the eardrum. - The middle ear is formed by the 3 smallest bones in the human body: the malleus, the incus and the stapes.
- The inner ear is composed of the cochlea. Filled with liquid, the cochlear canal has 20,000 ciliated cells (nerve cells which transmit the signals to the brain) in each ear.
Function of hearing
- Motor and reflex effects: position of the eyes and head. Maintaining balance.
- Effects on higher functions: thought, memory, language, body pattern, emotions.
- Sensory effects: position and movement of the head.
- Sensorial effects: perception of sound.
- Effects on state of consciousness and vigilance: triggering of sleeping and waking phases. Maintaining awakedness.
Sound circuit
 The sound arrives in the auditory canal - The sound causes the eardrum to vibrate
- The malleus and incus transmit the vibrations
- The inner ear decodes the sound and sends it to the auditory nerve
- The auditory nerve conveys the sound to the brain
- The brain analyses and interprets the sound
Download the Auditools awareness poster about the sound circuit (PDF - 379 Kb).
Functioning of the inner ear
 The vibrations set the liquid contained in the inner ear in motion.- The ciliate cells located in the liquid amplify the sound vibrations and select them by frequency. They transform the mechanical energy into nerve signals.
- The auditory nerve collects all the pulses emitted by the ciliate cells.
- The brain registers, analyses and interprets all the information.
Download the Auditools awareness poster about functioning of the inner ear (PDF - 208 Kb).
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