Problem:

In the mechanical part of the human eye the control system to protect for overload of the diaphragm in the iris with a strong coupling to the light intensity that falls on the retina has his place in the visual system as close as possible to the light source in the chain of control devices of the human visual system. The iris is disk-shaped and consists of two muscles. Like a diaphragm for light, the iris regulates how much light comes into our eyes. In bright conditions, the muscles of the iris limit how much light comes in. In lowlit conditions, the muscles of the iris increase the amount of light comming in.

Basic hypotheses is that the protection device in mammalian human hearing system is based on similarity as in the visual system and therefore should well also be using similar protection tools as used in the visual system and should well also be placed in the chain of control devices as close as possible to the signal source, as an experienced system engineer will always place a protection device in the chain of control devices as close as possible to the signal source.

Exists such an continuous functioning similarity analogue in the protection system for sound signals?

The iris in the eye (two muscles) and eardrum+ossicular chain in the ear (two muscles): in protection. Exists that similarity? Explain in detail.