Tinnitus is the perception of a phantom sound in the ear. It is characterized by the perception of a sound without any external source. The nature of this sound and its intensity vary from patient to patient.
Tinnitus can be temporary or permanent, mild or intense. It can also be accompanied by other symptoms: headaches, dizziness, loss of balance, sleep disturbances or reduced concentration. It is classified into several subtypes for better understanding: subjective and objective tinnitus, somatic tinnitus, pulsatile tinnitus, and low-frequency tinnitus.
Low-frequency tinnitus is one of the most confusing types because sufferers are usually unable to tell if the sound they hear is produced inside or outside their body.
Below, we examine low-frequency tinnitus in detail, including its causes and possible treatments.
What is tinnitus?
Tinnitus is often considered a symptom rather than a disease in itself. This is because it usually signals a problem affecting your ears, their related structures, or nearby areas.
Common causes of tinnitus include exposure to loud noise, ototoxic medications, autoimmune diseases of the inner ear, earwax impaction, aging, head trauma, and ear diseases. Tension in the head and neck muscles, as well as temporomandibular joint (TMJ) disorders, can also cause tinnitus.
No two cases of tinnitus are identical. In other words, even if the cause is the same for two patients, their symptoms will differ, and the impact on their lives will not be the same.
Let's review them.
Types of tinnitus
1. Subjective tinnitus
Subjective tinnitus is the most common type. The patient is the only one who hears the sound. Its main cause is exposure to loud noise; it can be temporary or permanent depending on the severity of the damage to the ears.
2. Objective tinnitus
This is a very rare type of tinnitus. Unlike subjective tinnitus, objective tinnitus is not perceived only by the patient: an audiologist can also hear it with a stethoscope.
Objective tinnitus is often due to vascular malformations or involuntary muscle contractions.
Since healthcare professionals can usually identify its cause, it is the only type of tinnitus they can cure. Once the underlying condition is treated, the ringing stops.
3. Neurological tinnitus
Neurological tinnitus is often linked to a dysfunction of the brain's auditory functions. These can be disrupted by conditions like Meniere's disease, which impairs the brain's ability to interpret sound signals sent by the inner ear.
4. Somatic tinnitus
Somatic tinnitus originates from a disorder of the sensory system. It can be triggered or aggravated by the movement of certain body parts. In most cases, its origin is outside the ears, such as muscle spasms.
5. Pulsatile tinnitus
Pulsatile tinnitus is synchronized with the patient's pulse or heartbeat. It is often caused by turbulence or increased blood flow in vessels near the ear. This turbulence can have several origins, such as blocked vessels.
6. Musical tinnitus
Musical tinnitus is also known as auditory imagery or musical hallucinations. Instead of hearing random noises in their ears, affected individuals perceive a melody or tune. This type of tinnitus is common in people with hearing loss.
What is low-frequency tinnitus?
Low-frequency tinnitus sounds like the two lowest octaves of a piano. It is often described as a dull hum, murmur, or rumble.
Due to the nature of this sound and the uncertainty of its origin, it is one of the types of tinnitus that most heavily impacts patients.
Low-frequency tinnitus is not just annoying: some patients describe it as a noise that can drive one mad, or even make one doubt one's own sanity.
Low-frequency tinnitus can also sound like a deep hum. This is why people experiencing another phenomenon, called "The Hum," easily believe they suffer from tinnitus, although this is not exactly the case.
What is "The Hum"?
"The Hum" refers to recurring reports of an annoying, low-frequency hum, rumble, or drone that not everyone can hear. Residents of the United States, United Kingdom, New Zealand, and Canada have reported this phenomenon.
Although it is most often called "The Hum," some regions of the world have given it their own name. You may have heard of the "Taos Hum" in New Mexico or the "Windsor Hum" in Ontario.
Some attribute "The Hum" to local mechanical sources: industrial sites, road traffic, or air traffic.
Despite studies conducted by scientists, its true origin remains a mystery.
Am I hearing a real sound?
Scientists conducted a study in the United Kingdom to distinguish environmental hums from low-frequency tinnitus. People complaining of hearing a deep hum were tested to determine if the sound was produced internally or if it was an environmental sound actually transmitted through the air.
Acoustic tests included sound matching exercises and hearing acuity measurements. Researchers asked participants to differentiate between tinnitus and a real airborne sound. While the results showed that ten of the 48 participants indeed suffered from low-frequency tinnitus, the majority of cases could not be classified.
A doctor or audiologist can test your hearing and look for underlying causes of your tinnitus. Identifying a cause can improve your condition and rule out the hypothesis that your hum is related to "The Hum" phenomenon.
Is "The Hum" a form of low-frequency tinnitus?
Although some studies have attempted to demonstrate that "The Hum" and low-frequency tinnitus are one and the same, we do not believe this to be true. Indeed, many people who hear "The Hum" have gotten rid of it by changing locations. Some report having stopped hearing it after moving from one home to another, in the same city.
If a person can escape the hum in their ear by moving house, it is probably not tinnitus. This sound does have an external source; you just haven't identified it yet.
"The Hum" is a low-frequency sound, and low sounds can travel for miles due to their high energy content. This makes it difficult to pinpoint the exact source. People living near industrial areas, factories, or diesel locomotives often complain of hearing "The Hum."
Some audiologists believe that most cases of "The Hum" have a real origin in the physical world, associated with excessive attention paid to harmless background noises. The use of psychological and relaxation techniques can mitigate its effects.
Causes of low-frequency tinnitus
Now that we have established what is not a cause of low-frequency tinnitus (namely "The Hum"), let's look at the possible real causes of this particularly distressing subcategory.
Although the exact origin of low-frequency tinnitus is rarely identifiable, here are some known causes.
1. High blood pressure
High blood pressure can cause low-frequency tinnitus.
To understand this: blood pressure is the force exerted by blood on the walls of blood vessels. When it is too low or too high, it can change the viscosity of the blood. Viscosity is the thickness and stickiness of the blood; it determines how easily it flows through the vessels.
Hypertension is when systolic pressure (the pressure when the heart beats) exceeds 130 and diastolic pressure (the pressure when the heart rests between beats) is above 80.
When your blood pressure is high, the viscosity of your blood increases, which reduces blood flow in your capillaries. The capillaries that supply the inner ear structures can then no longer deliver the necessary amount of blood. In the long run, this can lead to hearing disorders, including tinnitus.
In addition to this blood pressure variation causing a deep ringing in the ear, the medications used to treat hypertension can also cause tinnitus.
Some antihypertensives are ototoxic: their side effects can impair hearing and trigger tinnitus. This is the case with high-dose loop diuretics and high-dose aspirin.
2. Anxiety and stress
It may seem surprising, but anxiety and stress can cause or worsen tinnitus. Studies have shown that people suffering from post-traumatic stress disorder are more prone to tinnitus.
Stress and anxiety don't just cause tinnitus: they also raise blood pressure. And, as you already know, high blood pressure can cause low-frequency tinnitus.
When you are stressed, your body produces hormones that increase blood pressure. This accelerated blood flow can make the sound of blood circulating in your body audible.
The relationship between tinnitus and stress is circular. Stress and anxiety can cause tinnitus, and tinnitus, in turn, aggravates stress and anxiety. Anxiety makes you pay more attention to the noise, which amplifies its impact on your life.
Diverting your attention from this noise and following appropriate treatment for post-traumatic stress disorder can reduce the perception of this tinnitus.
3. Poor blood circulation
There is a link between heart health and hearing. Heart diseases like atherosclerosis can narrow or stiffen your arteries.
When arteries are diseased, they can become clogged with plaque. In the most severe cases, they can even contract and rupture.
When plaque blocks your arteries, your blood circulation suffers. The inner ear then does not receive sufficient blood flow.
The survival and proper functioning of the hair cells in the inner ear are highly dependent on an adequate blood supply, as they receive oxygen through the blood.
The hair cells located in the cochlea, within the inner ear, convert the sound transmitted by the middle ear into electrical impulses sent to the brain, where they are interpreted as sounds.
Deprived of oxygen by poor blood circulation, these cells can be damaged. This damage can cause phantom noises (tinnitus) in the ear. And if the hair cells are destroyed, hearing loss can occur.
The hair cells in the inner ear do not regenerate: unfortunately, any hearing disorder due to their destruction is therefore permanent.
Treatment for low-frequency tinnitus
There is no known cure for tinnitus. In most cases, what is prescribed as "tinnitus treatment" does not treat the tinnitus itself, but the underlying condition causing it. Once the cause is identified and addressed, the tinnitus lessens and eventually disappears.
Treating low-frequency tinnitus becomes a real challenge when the actual cause of the ringing remains unknown, and most affected individuals don't know where their hum comes from. In these situations, healthcare professionals usually prescribe standard treatments and therapies to alleviate symptoms.
Here are the treatments and therapies that can relieve the symptoms of low-frequency tinnitus.
1. Tinnitus Retraining Therapy (TRT)
Tinnitus Retraining Therapy aims to re-educate the brain, auditory system, and central nervous system to receive, process, and interpret sounds.
It consists of two components. The first involves a series of counseling sessions aimed at finding ways to ignore the tinnitus sound, just as one ignores background noise.
The second component uses sound therapy to reduce or mask the tinnitus sound. An audiologist places a device in the patient's ear that generates a low-intensity sound, at the same volume and pitch as the tinnitus.
Retraining therapy lasts 12 to 14 months. It is now recognized as the most effective treatment for tinnitus. Patients begin to feel relief after six months.
2. Cognitive Behavioral Therapy
Cognitive Behavioral Therapy is a psychosocial psychotherapy aimed at helping people manage negative thoughts to improve their mental health.
It effectively treats low-frequency tinnitus, especially when caused by stress and anxiety.
CBT helps patients identify and change disruptive and destructive thought patterns that negatively influence their emotions and behaviors.
Through this therapy, patients focus less on the tinnitus sound and its repercussions in their lives.
Changing one's perception of this annoyance diverts attention, makes the sound less noticeable, and reduces the anxiety and stress it causes.
3. Tinnitus masking
During masking, the audiologist plays an external sound that affects the tinnitus sound. Low-frequency tinnitus can sometimes become more noticeable at night or in quiet environments; tinnitus maskers can then relieve these symptoms.
Maskers generate white noise, which introduces natural and artificial sounds into the patient's environment. This masks the tinnitus sound and makes it less noticeable.
Maskers are worn over the ear or placed in the room. In the absence of a dedicated masker, an air conditioner, humidifier, or fan can be used to produce a comparable white noise effect.
4. Lifestyle changes
Modifying one's lifestyle can reduce the severity of low-frequency tinnitus. This is very effective when it is caused by an identified problem, such as high blood pressure.
Here are the changes you can make:
Engage in regular physical activity
Adopt a healthy diet
Lose weight
Follow mindfulness-based stress reduction therapies
Reduce your salt intake
Quit smoking and drinking
Reduce your caffeine intake
Consult a professional for stress and anxiety
Conclusion
Low-frequency tinnitus is among the most annoying, but with appropriate medical follow-up and good advice, you can achieve real symptom relief.
During your treatment, be sure to take care of your mental and emotional health. Avoid activities or situations that may increase your stress and anxiety, and try relaxing activities such as yoga and meditation.
"While tinnitus is difficult to live with, there is hope. With a few minor adjustments, most people can significantly improve their situation." - Drew Sutton, MD, board-certified otolaryngologist.
If you are treating a condition with a medication that you suspect is worsening your tinnitus, inform your doctor immediately so they can prescribe an alternative.
Sources:
Tinnitus: Ringing in the ears and what to do about it | Harvard Health
Summary of the 'Windsor Hum Study' Results | Canada
The effect of tinnitus retraining therapy on chronic tinnitus: A controlled trial | NCBI
