hørselsbenene

Hørselsbenene, also known as ossicles, are three small bones in the middle ear of mammals. They are the malleus, incus, and stapes. These bones are crucial for transmitting sound vibrations from the eardrum to the inner ear. The malleus, or hammer, is attached to the eardrum and transmits vibrations to the incus. The incus, or anvil, acts as a bridge between the malleus and the stapes. The stapes, or stirrup, is the smallest bone in the human body and fits into the oval window, a membrane-covered opening to the cochlea, the auditory portion of the inner ear.

The primary function of the ossicles is to amplify the sound waves and impedance match the air-filled middle ear to the fluid-filled inner ear. This amplification is necessary because sound waves travel less efficiently from air to fluid. The ossicles work as a lever system, with the malleus and incus providing leverage and the stapes acting as a piston. This mechanical action increases the pressure of the sound waves, allowing them to effectively stimulate the fluid in the cochlea. Damage or abnormalities in the ossicles can lead to conductive hearing loss, a condition where sound is not effectively transmitted through the outer or middle ear.