How are sound vibrations converted into mechanical vibrations available to the auditory receptors?

Guided by the auricle, air enters the ear canal. The diameter of the passage is smaller than that of the shell and the air vibrations are amplified, setting the eardrum in motion. It transmits vibrations to the auditory ossicles of the middle ear: the hammer, incus and stapes. Here the force of vibrations increases more than 30-50 times. The streamer presses on the oval window of the snail and sets the fluid in it in motion. Fluctuations in the fluid excite the auditory receptors – a nerve impulse arises.