Final answer:
The involuntary reaction to protect the inner ear from loud sounds is called the acoustic reflex. This reflex involves two muscles in the middle ear that quickly attenuate the energy transmitted to the cochlea. Humming can activate this reflex, providing some protection from loud noises like gunfire.
Step-by-step explanation:
The Involuntary Reaction to Loud Sounds in the Ear
The involuntary reaction that protects the inner ear from very loud sounds is known as the acoustic reflex. This reflex is mediated by two muscles in the middle ear that react to intense sounds in a matter of milliseconds. Their function is to reduce the amount of mechanical force that is transmitted to the cochlea, thereby protecting the delicate structures within the inner ear from potential noise damage.
For example, when a person hums while shooting a gun, this action can activate the acoustic reflex. The vocalization triggers those two muscles in the middle ear, which in turn helps to diminish the sound energy reaching the cochlea, hence mitigating the risk of auditory trauma.
The other options provided, such as auditory masking, tinnitus, and phonophobia, refer to different concepts within the field of audiology. Auditory masking is a phenomenon where the threshold of hearing for a sound is increased by the presence of another (masking) sound, tinnitus is the hearing of sound when no external sound is present, and phonophobia is a fear of loud sounds.