The tensor tympani is a muscle located in the middle ear. It is one of two muscles found in the tympanic cavity and resides in a canal resting above the auditory canal. The primary function of this muscle is to help reduce certain sounds, such as those made by the act of chewing. The tensor tympani nerve, a branch of the trigeminal nerve, provides the nerve supply for the tensor tympani muscle.
The tympanic cavity that houses this muscle is a small opening located in the middle ear. This cavity surrounds the small bones that are found in this area of the ear. Just below this cavity is the auditory canal, also known as the ear canal. This tube-like opening serves to connect the middle ear to the outer ear. The ear canal is prone to damage by such things as infection or fungi.
The tensor tympani muscle moves in a backward direction through the ear canal, ending in a thin tendon. This tendon makes its way into the tympanic cavity, then bends and turns around the septum. From there, it inserts into the malleus, a small bone located in the middle ear.
When this muscle is in a tensed state, it pulls the malleus in a medial position so the tympanic membrane is tensed as well. This reduces both the vibration and volume of sound in the middle ear, particularly the sounds created by the act of chewing. There are a variety of disorders which are capable of causing damage to the tensor tympani muscle.
Tensor tympani myoclonus is not actually considered a disease, even though the effects of this condition can be devastating to the patient. Those suffering from this disorder have described the sensation as feeling like there are butterflies or moths in their ear, wildly fluttering their wings. This is believed to be caused by the constant contracting of the tensor tympani muscle. Things such as stress or caffeine are thought to worsen the symptoms of this disorder. Medications can often be prescribed to help to control some of the symptoms of this condition.
Hyperacusis is another condition that can affect the muscles found in the ear. In this condition, the patient is not able to tolerate sound in a normal manner. The offending sound can be different from patient to patient and can cause high levels of anxiety. Sudden, loud noises are the most likely sounds to cause a reaction in those suffering from hyperacusis. Treatment options include medication, therapy, and in some cases, surgery.