Final answer:
The acoustic reflex protects the ear from intense sounds by the rapid contraction of the stapedius and tensor tympani muscles, which diminishes the energy transmitted to the cochlea and prevents potential damage.
Step-by-step explanation:
The acoustic reflex protects the ear from intense sounds through the contraction of the stapedius and tensor tympani muscles. When loud sounds reach the ear, these two muscles quickly contract, acting within milliseconds. This contraction reduces the amount of mechanical energy transmitted through the ossicles to the cochlea. Notably, this reflex can be triggered by external noises as well as voluntary actions, such as humming, which can protect the ear during loud events like fireworks or shooting.
The middle ear's lever system typically amplifies the force from sound pressure variations and channels it via the oval window into the cochlea. However, if this force is too intense, the acoustic reflex, involving the stapedius and tensor tympani muscles, swiftly kicks in to lower the force applied to the oval window, thereby protecting the delicate structures within the inner ear.