What Are the Causes of Tinnitus?

By Eric Sandler, Sc.D.

Tinnitus is strongly associated with hearing loss and in most cases, audiologists believe that tinnitus stems from damage to the outer hair cells of the cochlea. These sensory receptor cells can become damaged leading to less auditory stimulation reaching the brain. This lack of auditory stimulation leads the brain to create sound ‘tinnitus’ to fill in the ‘empty space’.

Other known causes of tinnitus include medication, stress, muscle tension, central pathology, and noise exposure. When tinnitus is associated with medication, it often times diminishes when the medication is stopped. It should also be noted that medication inducted tinnitus can worsen if the medication dosage is increased. Some of the medications that can cause tinnitus include certain antibiotics, anti-depressants, aspirin, quinine, some forms of chemo therapy, quinine, and diuretics. When stress and muscle tension are the cause of tinnitus, treating those conditions will often times lead to a reduction in tinnitus. 

Subjective vs objective tinnitus

Tinnitus can further be classified in two different ways, subjective tinnitus, the most common form of tinnitus, and objective tinnitus, a rarer form of tinnitus.

Subjective tinnitus can only be heard by the individual perceiving it, while objective tinnitus can also be heard by a doctor during an otologic evaluation. The cause of objective tinnitus can be vascular in nature. In cases like this, vascular flow is audible and would warrant further medical work up.

Objective tinnitus may also result from middle ear myoclonus. Middle ear myoclonus is potentially related to the tensor tympani or the stapedius tendon. 

The tinnitus case history

The case history is a very important part of the evaluation to attempt to diagnose the cause of a patient’s tinnitus. It is necessary to clearly state symptoms and characteristics of tinnitus during this otologic evaluation.  The more information that your doctor obtains, the more likely they will be to establish a correct diagnosis. Some of the questions you will encounter could include the following:

  • Is your tinnitus constant or pulsatile? Pulsatile tinnitus can be vascular in nature and indicate an underlying problem, warranting a further medical evaluation. 
  • What does your tinnitus sound like? Common answers will be; buzzing, hissing, chirping, and ringing. It is worth noting that what tinnitus sounds like, is a reflection of how a patient perceives their tinnitus, and perception varies from individual to individual.
  • How is your hearing? tinnitus is most commonly associate with age related sensorineural hearing loss, and this should always be ruled out in the presence of tinnitus. 
  • Have you had a history of noise exposure? Noise exposure is also a known risk factor for tinnitus. 
  • Do you clench your jaw or grind your teeth? These behaviors that put tension on the temporomandibular joint are also known risk factors for tinnitus. 
  • If your tinnitus has recently changed? Have you had a significant stress event recently or a change in your hearing? Stress in our daily lives can exacerbate tinnitus, it can make it seem louder, more constant, of a different pitch, and more troublesome. A change in the tinnitus experience can also be symptomatic of a change in underlying hearing function. 
  • Are there other ear-related symptoms? Tinnitus coupled with vertigo and or hearing loss, can be an indication of an inner ear problem (pathology). A patient may also present with tinnitus along with other symptoms when experiencing a sudden sensorineural hearing loss, acoustic neuroma (vestibular schwanoma), otitis media (middle ear infection) a TIA or CVA (stroke). 
  • Where do you hear your tinnitus? Is it in both ears, your head, or just one ear?  If tinnitus is only heard in one ear, it can be a symptom of an asymmetric sensorineural hearing loss, among other things. It would warrant a further medical evaluation. 

Once all information has been collected and assessed, you doctor will hopefully be able to identify the specific underlying cause of tinnitus and attempt to establish a treatment plan.