Types of Tinnitus
Tinnitus is a medical situation that results in the hearing of sound in the absence of any external sound. The noise that's heard can be a ringing, hissing, whooshing, buzzing, humming, whistling, or chirping sounds.
Tinnitus can affect one or both ears, and in some cases, it might seem like it's in the middle of the head or hard to pinpoint.
The noise can be continuous or intermittent. The loudness of the noise often varies, and it often gets worse when there is little or no background noise, especially at night.
Some people suffering from tinnitus often think that the noise is from an external source and will hunt for the noise source to no avail.
In some cases, older people interested in music and have suffered hearing loss have tinnitus that has a musical quality and sounds like a familiar song or tune.
Tinnitus is quite common, affecting people of different age groups, but it is more common in people who have ear problems or hearing loss.
Statistics from the U.S. Center for Disease Control shows that about 50 million Americans (15%) experience some form of tinnitus.
Most people who have tinnitus can carry on with their normal activities without any consequence; only a few people have complained of tinnitus having a drastic effect on their life.
Tinnitus is classified into three different types based on the type of sound the person hears. The types of tinnitus are explained below.
1. Subjective Tinnitus
This tinnitus type is the most common type of tinnitus; about 99 percent of tinnitus cases are subjective tinnitus.
Subjective tinnitus is also referred to as non-auditory tinnitus, non-vibratory tinnitus, or tinnitus aurium.
If tinnitus is subjective, the sounds that the person hears can not be detected by doctors or hearing technicians; only the tinnitus patient can listen to the sound.
Subjective tinnitus is often caused by exposure to excessive noise, and it can be accompanied by hearing loss, especially if the hair cell nerve is damaged.
Tinnitus caused by damage of the auditory nerve or the inner ear is called otic. However, if the tinnitus is not associated with the disorder of the auditory nerve, it is called non-otic.
There is also a type of subjective tinnitus known as somatic tinnitus. The sound’s intensity and frequency are altered by the person’s body movement, especially the neck and the head.
This is why somatic tinnitus is also referred to as craniocervical tinnitus.
Body actions like applying pressure to the neck and head, turning the eyes, and clenching the jaw can affect the sound.
For some persons, the tinnitus vanishes when they are sleeping and gets louder when they are awake; this is due to the lack of movement of neck muscles and the head when sleeping.
Causes of Subjective Tinnitus
Subjective tinnitus is often caused by abnormal neuronal activity in the auditory cortex.
The auditory cortex is a part of the temporal lobe responsible for the processing of information in humans.
When the auditory cortex begins to malfunction, input from the auditory pathway (this includes the cochlea, auditory nerve, and auditory cortex) is altered or disrupted.
This leads to creating new neural connections and the body’s inability to suppress intrinsic cortical activities.
Other known causes of subjective tinnitus are:
1. Hearing loss
This is a very common cause of subjective tinnitus. Hearing loss that is caused by injury to the cochlear often leads to tinnitus.
The cochlear can get damaged by exposure to extremely loud noise, and the hearing loss can either be temporary or permanent.
2. Ototoxic Drugs
Ototoxic drugs are drugs that can cause damaging side effects to the ear.
There are over 200 Ototoxic drugs that are sold over the counter and given by prescription. These drugs are used to treat health issues like cancer, infections, heart diseases, kid diseases, and pain relievers.
The effects of Ototoxic drugs can be temporary or permanent depending on the degree of damage done to the ear. The impacts of ototoxic medicines on the ear can lead to hearing loss or an increase in the ear’s susceptibility to getting damaged when exposed to loud noise.
Tinnitus associated with ototoxicity is usually high-pitched (it is higher than 2000 Hz).
3. Meniere Syndrome
Meniere syndrome or disease is a disorder of the inner ear and can result in loss of balance, feeling of fullness or congestion in the ear, dizzy spells, and hearing loss.
Meniere disease usually affects one ear, and it is a known cause of subjective tinnitus.
Tinnitus caused by Meniere syndrome is often low pitched (less than 1000Hz). It usually ranges between 125 and 500 Hz.
4. Other Causes
Other factors like discontinuation of prescribed drugs like benzodiazepines and bupropion can cause subjective tinnitus, which can persist for months.
Also, issues like head injury, acoustic shock, neurological disorder, lead or mercury poisoning, vitamin B12 deficiency, depression, psychiatric disorder, eustachian tube dysfunction, and iron deficiency anemia vasculitis could lead to subjective tinnitus.
Less than 1% of total tinnitus cases are objective.
Objective tinnitus, also known as pseudo-tinnitus or vibratory tinnitus, is a rare type of tinnitus caused by a vascular condition or the involuntary twitching of a muscle or group of muscles.
Muscle spasms around the middle ear can also cause it.
Objective tinnitus can be heard by other people, especially using a stethoscope.
People with objective tinnitus have eustachian tube dysfunction, vascular abnormality, or neurologic disease, and the symptoms can worsen at night.
In hypertensive patients, a soft, low pitched venous hum can be heard.
This hum can often be heard in the anterior neck and upper chest, and it is caused by turbulence in the internal jugular vein.
This turbulence causes the vessel's walls to vibrate. However, the hum can be altered by pressure on the jugular, positioning, and movement of the head.
When objective tinnitus is associated with an exposed eustachian tube, it is in sync with breathing, especially when a person is in an upright position.
When the person lays down, snorts, or sniffs, the tinnitus gradually disappears.
Objective tinnitus associated with the abnormal muscular contractions of the middle ear muscle often comes with a regular clicking sound, continuous clicking sound, or series of sharp sounds.
Causes of Objective Tinnitus
Various factors can cause objective tinnitus; below are some of the possible causes of objective tinnitus:
- Disorders that affect the vascular system and muscular system can cause objective tinnitus.
This is the reason why the person hears vascular noises from the internal jugular vein. Vascular tumors, vascular stenosis, and intracranial hypertension can also cause objective tinnitus.
- Neurologic disorders like idiopathic stapedial muscle spasm and spasms associated with multiple sclerosis and brain stem tumor can cause objective tinnitus.
- Exposed eustachian tubes can also cause objective tinnitus. In this case, the person hears blowing sounds in their ears, which coincides with their breathing. This is often caused when the person has lost significant weight.
The good thing about objective tinnitus is that the causes can be easily identified, and this means that the tinnitus can be treated, unlike subjective tinnitus, which is often incurable.
Pulsatile tinnitus is a form of objective tinnitus that is in tune with the pulse of the person. Pulsatile tinnitus is also known as vascular, rhythmic, or pulse-synchronous tinnitus.
Pulsatile tinnitus can be caused by increased blood turbulence near the ear, altered blood flow, or increased awareness of blood flow in the ear.
People with pulsatile hear a pulsating thumping or whooshing sound that is often loud, distracting, and in some cases.
Other symptoms like hearing loss, vision problems, headaches, and dizziness also occur, especially if they suffer from idiopathic intracranial hypertension (high pressure in the fluid around the brain).
Several reasons can cause pulsatile tinnitus. Below are certain health problems that can lead to this type of tinnitus.
1.Hyperactive Thyroid Gland or Anemia
When the thyroid is overactive, it causes blood to flow quickly and loudly, causing pulsatile tinnitus.
2. Irregular Blood Vessels
This is one of the most common causes of pulsatile tinnitus. When blood flows through kinked or damaged vessels in the brain around the ear or through a narrow artery or vein, it can lead to tinnitus.
Atherosclerosis is the hardening of the arteries due to the clogging of fats or cholesterol in them. This clogging of fats in the blood vessels makes them less flexible.
This lack of flexibility causes the blood moving through the middle and inner ear to flow with more force. Pulsatile tinnitus caused by Atherosclerosis can often be heard in both ears.
4. High Blood Pressure
People with high blood pressure are often susceptible to pulsatile tinnitus; the increase in blood pressure flowing through the blood vessels can create a rhythm. The tinnitus often gets worse and more noticeable when the person is stressed or takes caffeine or alcohol.
Tumors in the head or neck can put pressure on blood vessels, causing noise to be heard in the head.
Also, if there is a connection problem between arteries and veins, pulsatile tinnitus may be experienced.
Other Causes of Tinnitus
Asides from the various causes of each type of tinnitus that we have examined above, other factors can cause tinnitus; let’s examine them.
1. Inner Ear Hair Cell Damage
The delicate hairs in the inner ear play a vital part in hearing sound; they move with the pressure of sound waves.
This movement triggers cells to send out an electrical signal from the ear to the brain through a nerve. It is this signal that the brain interprets as sounds.
When the inner ear hair cells are damaged, they may begin to send random electrical impulses to the brain; this results in tinnitus.
Damage to inner ear hair cells is a common cause of tinnitus, but unfortunately, the damage can not be repaired. This means that the person may have to live with the tinnitus permanently.
2. Exposure to Extremely Loud Noise
One of the significant causes of tinnitus is constant exposure to loud noises.
Noise exposure has been identified as one of the major causes of damage to inner ear hair cells, which we discussed above.
About 30 million workers in the United States are exposed to hazardous noise levels. Also, tinnitus is the major cause of service-related disability among veterans.
Loud noises from firearms, heavy equipment, motorcycles, chain saws can cause tinnitus.
Exposure to loud musical noise from earpods, earpieces, concerts, clubs, and bars can damage the ear.
This is why musicians are 57 percent more likely to have tinnitus and 400 percent more likely to have hearing loss than the general public.
Tinnitus caused by exposure to loud noise can either be temporary or permanent, depending on the level of damage done to the ear.
3. TMJ disorders
The temporomandibular joint is the joint that connects the jaw to the skull. This joint acts as a hinge and makes the movement of the jaw easy.
When the TMJ is damaged, it causes a localized pain disorder known as TMJ syndrome or disorder.
This damage can be caused by the jaw or teeth’ misalignment, arthritis, poor posture, gum chewing, teeth grinding, or injury to the jaw or teeth.
Common symptoms of TMJ disorder are jaw clicking, earache, headaches, sore jaw muscles, locking of the jaw joint, pain in the temple area, and jaw pain.
TMJ disorder also results in tinnitus. This disorder can easily be treated, and the associated tinnitus disappears when the disorder is corrected.
Thirty percent of seniors experience tinnitus.
Age is a common cause of tinnitus, especially amongst older adults. The older a person gets, the more weak the person’s hearing and the more susceptible they are to hearing challenges.
Older people who suffer hearing loss usually suffer tinnitus.
While some of this hearing loss may not be curable, there are other ways, such as hearing aids, those older people can be assisted with hearing.
5. Muscles Spasm or Ear Shock
The muscles in the ear that control the tension of the eardrum can involuntarily contract or spasm occasionally.
The two major muscles that experience this spasm are the stapedius muscles and the tensor tympani muscles.
These muscles are responsible for dampening and reducing the noise coming from inside the body and outside the ear. The repetitive and synchronized contraction of these muscles can cause tinnitus.
Muscle spasm in the ear can be caused by exposure to loud noise, spasm in the facial nerves, and extreme fatigue.
People with a neurologic disease like multiple sclerosis are also susceptible to ear muscle spasms.
6. Earwax Blockage
The ear canal naturally produces a waxy oil known as cerumen or earwax, which prevents foreign particles, water, dust, or micro-organisms from getting into the ear.
Naturally, ear wax comes out of the ear canal to the ear opening, where it can be cleaned out. However, if the ear canal produces more earwax than necessary, it can get hard and block the ear.
While some people are prone to excessive buildup of earwax, this natural buildup cannot result in blockage except it is tampered with.
Using objects like bobby pins and cotton swabs can push earwax back into the ear canal and cause a blockage.
Earwax blockage can irritate the eardrum, cause hearing loss or tinnitus.
Tinnitus caused by earwax blockage can be cured when the blockage is removed. Don't try to get rid of the blockage by yourself; you will only push it further and seek medical help.
The process of getting rid of the blockage is usually very easy and painless.
7. Arteriovenous Malformation (AVM)
This is a rare condition where there is an abnormal tangling of blood vessels that connect the veins and arteries.
When these veins and arteries tangle, they bypass normal tissues. That said, there is no known reason for this abnormal tangling.
Most people with AVM got it from birth, and some may not experience AVM’s symptoms. The symptoms of AVM in a person can vary based on where the tangling happens.
Symptoms include buzzing sound in the ears, backache, seizures, headache, change in vision, and muscle weakness.
If the tangling happens in the head or anywhere close to the ear, it can cause tinnitus, and it is often experienced in one ear.
8. Acoustic Neuroma
Acoustic Neuroma which is also known as vestibular schwannoma is a noncancerous tumor that develops on the vestibular nerve, which goes from the inner ear to the brain. The vestibular nerve plays a vital role in hearing and balance.
This tumor usually grows slowly or doesn't grow at all, but in very rare cases, it can grow until it gets large enough to press against the brain.
The tumor can cause instability, ringing in the ear (tinnitus), and hearing loss. Acoustic neuroma can be treated by radiation and surgical removal.
While some of the tinnitus types discussed in this post can be cured, some of them are permanent.
Therefore, it is essential to do your best to protect your ears from anything that can cause tinnitus or other associated hearing problems. If you notice any form of tinnitus, don't self medicate, seek immediate medical help.
Have you suffered any of these types of tinnitus? Share your experience with us.
Drew Sutton M.D.
Drew Sutton, MD is a board-certified otolaryngologist. He has extensive experience and training in sinus and respiratory diseases, ear and skull base surgery, and pulmonary disorders. He has served as a Clinical Instructor at Grady Hospital Emory University for more than 12 years.