In response to loud sounds, the tensor tympani muscle tightens the eardrum and through the tendon between the hammer and anvil and shifts the stirrup backward from the oval window of the inner ear. This shifting of the ossicles reduces the transmitted force to the inner ear, protecting it. However, it is a relatively slow action and cannot protect the ear from sudden loud sounds like a gunshot. The process is less effective in older ears.

A young person's ear can provide a limited amount of protection from sustained loud sounds by shifting the stirrup backward so that it doesn't exert as much force on the oval window. In the very young, the stirrup is thought to be capable of actually breaking contact with the oval window, breaking the direct link to the inner ear. In an older ear, the structures become stiffer and cannot adjust backward as much. Older persons are generally less tolerant of loud sounds.