Westcott M et al. Tonic Tensor Tympani Syndrome in Tinnitus and Hyperacusis Patients: A Multi-Clinic Prevalence Study. Noise and Health Journal, Mar-Apr 2013, Volume 15, Issue 63 pp117-128
Acoustic shock and TTTS Guide for Medical Professionals
In the middle ear, the tensor tympani muscle and the stapedial muscle contract to tighten the middle ear bones (the ossicles) as a reaction to loud, potentially damaging sounds. This provides protection to the inner ear from these loud sounds.
In many people with tinnitus, particularly if they have developed hyperacusis, an increased, involuntary activity can develop in the tensor tympani muscle in the middle ear as part of a protective and startle response to some sounds. This lowered reflex threshold for tensor tympani contraction is activated by the perception/anticipation of sudden, unexpected, loud sound, and is called tonic tensor tympani syndrome (TTTS). This response can then generalise to other types of sound and to lower sound volume levels, resulting in the development as well as the potential escalation of hyperacusis. In some people with hyperacusis, it appears that the tensor tympani muscle can contract just by thinking about a loud sound.
TTTS typically does not develop in people with misophonia.
Following exposure to intolerable sounds, this heightened contraction of the tensor tympani muscle can:
- affect the opening of the Eustachian tube, which ventilates the middle ear cavity, and is normally closed but opens when we yawn or swallow
- tighten the ear drum
- stiffen the middle ear bones (ossicles)
- lead to irritability of the trigeminal nerve
As a result, TTTS can cause a range of symptoms in and around the ear(s). These include: pain, numbness and burning sensations in and around the ear; pain in the jaw joint and down the neck; the development of tinnitus or an increase in pre-existing tinnitus; a clicking / fluttering sensation in the ear; a sensation of blockage, fullness or frequent "popping" in the ear; unsteadiness; muffled hearing.
It is important for people with hyperacusis to accept and understand the neurophysiological basis of TTTS, which is responsible for many of the physical sensations experience in their ears after exposure to an intolerable sound.
It does not harm the ear to experience TTTS, and even though the TTTS symptoms can seem as if the ear is being damaged by some sounds, this is not the case. Moderate, everyday sounds are safe and do not harm the ear or cause a hearing loss.
TTTS-like symptoms may be due to middle or inner ear pathology, and medical investigation should be carried out to exclude this possibility. Conversely, TTTS symptoms in people with hyperacusis can be mistakenly diagnosed as due to middle/inner ear pathology or jaw joint dysfunction or temporomandibular disorder (TMD).
It is therefore important for people with tinnitus and hyperacusis who experience these symptoms to consult an Ear, Nose and Throat Specialist/TMD Specialist to ensure there is no underlying medical condition causing them.
As TTTS develops from the way intolerable sound is perceived in the brain, using strategies aiming for tinnitus habituation and hyperacusis desensitisation will help reduce TTTS symptoms. Individual guidance from a physiotherapist for relaxing the facial muscles in and around the ear, as well as identification and massage of any muscular trigger points in the shoulder and neck, can be of benefit.