How does the hearing process work?

"Make everything as simple as possible, but not simpler", Albert Einstein said. Here we are.

The sound wave is modelled as a series of magnetically coupled pendulums, the middle ear as a chain of levers, and the inner ear another series of pendulums coupled by a string.

What can you do with it, and how does the simple mechanics relate to the physical and physiological processes?

Which aspects are missing in the models?

Longitudinal pendulum sound wave

What happens if a sound source vibrates or generates pulses? What can you observe after you push the first molecule (pendulum) once?

Can you relate what you see to acoustic phenomena that you can hear?

Which properties of a sound wave (1) can you observe in the experiments? What happens if you remove pendulums, or generate a vacuum?

The middle ear levers and pistons

How does the sound wave get into the inner ear? Very simple, actually, through the middle ear(2). But, which functions does the middle ear have?

What is totally wrong in the wooden middle ear model? A short hint - it might have to do with one of the ossicles. In reality it does not act as a lever, it rather behaves like the second of two pistons in the middle ear.

The inner ear - a pendulum chain?

There is something vibrating in the inner ear, also called the cochlea (3). Is it a chain of pendulums with different lengths (4), or is it membranes which are being pushed back and forth by the fluids in the inner ear? What do the pendulums and the membrane have in common? The pendulums change in length - what might the most important membrane in the inner ear (5) change?

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