Tinnitus – noises in the ears or head
What causes it and how to deal with it
Mr James W Fairley BSc MBBS FRCS MS Consultant ENT Surgeon
© 1993 – 2014 JW Fairley Last updated 21 August 2014
- What is tinnitus?
- What does tinnitus sound like?
- Is tinnitus a high pitched ringing in the ears?
- How loud is tinnitus?
- How long does tinnitus last?
- Is tinnitus permanent?
- Is hearing voices in your head tinnitus?
- What causes tinnitus?
- Normal tinnitus
- Objective and subjective tinnitus
- Theories of tinnitus
- Hearing pathway: sound » ear » nerve of hearing » brain
- Reverse pathway: brain » nerve of hearing » ear » sound
- Adjusting the cochlear microphone
- Normal brain sound processing can generate tinnitus
- Investigation of tinnitus
- Practical ways of dealing with tinnitus
- Severe tinnitus
- Why some tinnitus becomes severe
- Threat detection and false alarms
- Emotional areas of the brain affect sound processing
- Extreme tinnitus
- Clinical depression and tinnitus
What is tinnitus?
Tinnitus ( TIN-it-tuss ) means hearing noises which have no external source. The noises can appear to be coming from
- in the ears
- in the head
- somewhere outside
It can be hard to tell where they are coming from.
What does tinnitus sound like?
There are lots of different kinds of tinnitus. Some people with tinnitus only ever hear one sound. Others hear a variety of different noises. Some hear only one sound at a time. Others hear multiple noises, all at once.
Is tinnitus high pitched ringing in the ears?
The pitch of tinnitus can be
- high frequency – hissing, whistling or ringing
- low frequency – buzzing, roaring or rumbling
- mixed and variable in pitch, different combinations of sounds
How loud is tinnitus?
Tinnitus can be
- very loud
- very quiet
- variable in volume
Loudness of tinnitus is only part of the picture. Some people find even a quiet noise very intrusive and annoying. Others can tolerate and ignore quite loud noises.
How long does tinnitus last?
Tinnitus can last
- a few seconds
- a lifetime
- anywhere in between
Is tinnitus permanent?
- come and go
- be permanent
Most people with permanent tinnitus find that it fades away with time, and it is not noticeable unless they listen for it.
Is hearing voices in your head tinnitus?
Hearing voices is not tinnitus. Hearing voices is usually a symptom of mental illness.
What causes tinnitus?
Tinnitus can be like the sound of a sea shell held to the ear.
Tinnitus is often caused by wear and tear on the hair cells of the inner ear. Noise damage is cumulative over a lifetime. People in noisy jobs, like musicians, are more likely to get tinnitus from excess noise exposure.
To hear tinnitus occasionally is normal. Nearly everyone experiences momentary noises that come and go. Temporary tinnitus – lasting minutes or hours often follows exposure to excessively loud noise. Persistent tinnitus is often caused by loss of hearing, and is common with ageing. More severe forms of tinnitus are usually due to anxiety or stress. Occasionally, tinnitus is a symptom of more serious disease of the ear or brain.
Nearly everyone will get tinnitus in a completely quiet, sound-proofed room, or if you hold a sea shell to the ear.
The commononest cause of persistent tinnitus – noises that don’t go away by themselves – is loss of hearing. The loss of hearing may be very slight, not enough to notice, but it is enough to cause tinnitus.
Objective and subjective tinnitus
There are two kinds of tinnitus – objective and subjective.
Objective tinnitus – Somato-sounds or body noises
Objective tinnitus is a noise, coming from inside you, that can be heard by someone else. These have also been called somato-sounds, and are just noises made by the normal working of the body. Examples include
- the sound of blood flowing through vessels near or in the ear
- the sound of Eustachian tube opening and closing when you swallow or yawn
- the sound of your jaw joint working
- the sound of joints in your neck creaking
If you have some disturbed blood flow in an artery near the ear, you might hear the noise of the blood flowing through the constriction. The noise would be similar to that you get from a kink in a hose pipe. A doctor who puts a stethoscope over the artery will hear the same noise you hear. That is objective tinnitus.
Subjective tinnitus is a noise, seeming to come from inside you, that only you can hear. Until recently, doctors thought people imagined these noises. But they aren’t imaginary. The noise is there. It is made inside the sound processing pathway, from the ear to the brain. Tinnitus can come from the cochlea of the inner ear, inside the microphone. It is extremely quiet – not audible – to anyone outside, but to the person whose cochlea is making tinnitus, it is all too audible, because it is produced inside the microphone.
If we were able put a tiny, miniaturised microphone inside your cochlea, and feed the signal to an external amplifier and speakers, we could probably hear exactly the same tinnitus that you hear. That would make it objective. Most cases of what we thought were subjective tinnitus are objective. We just don’t have the means of listening to it. We can’t put a microphone inside your cochlea to find out, because that would deafen the ear.
Theories of tinnitus
There are various theories of how tinnitus is produced. A theory is an idea of what might be true. Scientific theories evolve over time. They are judged by how well they fit the observed facts, and whether they can generate tests – experiments. A theory that cannot be disproved by experiment is not a scientific theory. Good scientists welcome challenges to their theories. Theories are placed in the public domain only to be knocked down, tested to destruction. A strong scientific theory is one which has withstood many attempts to prove it false. The following is based on modern ideas of how the cochlea works, and how sound signals are processed in the brain.
Normal brain sound processing can generate tinnitus
The sound processing pathways in the brain can filter and amplify selectively. Some of the sounds that we hear arise from this internal processing. If you turn the volume on your stereo right up, but there is no input, you will probably hear a humming sound. Tinnitus can result, in a similar way, from normal brain sound processing activity.
The brain processes sound in lots of of complex pathways. This electrical activity can sometimes be heard. Like the faint hum you might hear from your stereo amplifier, it just means it is working. This processing can be heard if conditions are right – for example, in a completely sound proof room, with no external sounds, nearly everyone will hear something. They are hearing the normal sound processing that goes on in the brain. It is when these sounds become amplified that we call it tinnitus.
Hearing pathway: sound » ear » nerve of hearing » brain
- The cochlea is a biological microphone.
- Its job is to turn the mechanical vibrations of sound into electrical signals in the nerve of hearing
- The electrical signals – digital – are then sent up into the brain, where you hear things.
But it’s not quite as simple as that.
Reverse pathway: brain » nerve of hearing » ear » sound
MRI scan through the inner ears, nerves of hearing and brain showning two way traffic of signals in the nerve, from ear to brain, and brain to ear.
Recordings from the nerve of hearing show there is two way traffic. Electrical signals are downloaded, from the brain to the ear, as well uploaded, from the ear to the brain. This is because the cochlea is not just a simple passive microphone. It is an active microphone. And its performance is software controlled, by the sound processing area of the brain.
- The sound processing area of the brain process the raw signals, integrating them from both ears. Normally, we don’t consciously hear this processing.
- The processed information is then passed up to the higher centres of the brain, where we consciously hear things.
Adjusting the cochlear microphone
Unlike the sound engineer, we only have one kind of microphone, the cochlea. But the microphone can be adjusted, by feedback from the brain, to work well in many different environments. The software control is automatic, which is great for us. But it may also become a cause of tinnitus.
Sound engineers use different microphones for different environments, such as
- outside broadcast
We humans only have one kind of microphone – the cochlea. But the microphone can be adjusted to listen in different environments. The adjustments are made for you, automatically, by nerve signals from the sound processing area of the brain. These signals travel backwards, down the nerve of hearing. They are received and acted on by the outer hair cells of the cochlea.
This ability to control the cochlea makes us very adaptable. We can hear the quietest crack of a twig when a predator approaches, but also make out a familiar voice in a noisy crowd. This gives us a survival advantage. But it is probably also why we get tinnitus.
- Tinnitus is generated when the sound processing area of the brain realises it is not getting the full signal it has grown to expect from the inner ear.
- It sends a signal backwards down the nerve, trying to encourage the deficient hair cells to work harder.
- Unfortunately they can’t. They are damaged. The brain is trying to force them to work properly, but it is flogging a dead horse.
- This nagging signal is like reversing the current on a microphone. It just sends them off vibrating, hence producing a sound which is heard as tinnitus.
Turning up the automatic volume control
If the sound processing area of the brain is not getting the full signal, it turns up its automatic volume control. Some amplified signals are then heard as tinnitus. Turning up the automatic volume control can also result in hyperacusis. In hyperacusis, everyday sounds, at volumes that most people find perfectly comfortable, are felt to be intolerably loud.
Investigation of tinnitus
Tinnitus is a symptom, not a disease. Most patients with tinnitus do not have any serious medical condition. However, a small minority do. It is the doctor’s job to look for the causes of tinnitus. The search will focus on the ear and the brain.
Medical investigation of tinnitus can be divided into three stages:
- special investigations
Heavy metal fans at an open air rock concert. Ringing in the ears after exposure to excessive noise indicates damage to the hair cells of the cochlea. Photo from Metal – a Headbanger’s Journey. Warner Home Video
The nature, onset and time course of the tinnitus can help diagose the cause. For example:
- Ringing in the ears that comes on after attending a loud rock concert is likely to be due to noise damage.
- Tinnitus that comes on following diving or flying with a cold is likely to be due to a pressure problem with the Eustachian tube.
Other symptoms, such as
- hearing difficulties
are all important clues in making the diagnosis.
Microsuctionof the ear
Conditions of the outer ear, middle ear and inner ear can all give rise to tinnitus.
Careful examination of the ear is, therefore, essential.
In order to examine the ear properly, any wax will need to be removed. This may require microsuction.
If there is any associated history of vertigo or unsteadiness, a neurological examination will be needed.
Audiometry (hearing test) is essential, since most cases of tinnitus are due to hearing loss. If there is no obvious cause for the tinnitus in the ear, and especially in cases of unilateral tinnitus (tinnitus affecting only one ear) MRI scan of the brain may be needed. The purpose of the scan is to exclude the small possibility of a benign tumour, pressing on the nerve of hearing. About 2% of MRI scans done for the investigation of unilateral tinnitus find a tumour. Many of those found are very small. They tend to grow slowly. Some don’t grow at all, and are best left alone. We need to know what is or isn’t there.
Practical ways of dealing with tinnitus
When tinnitus has been investigated, and serious disease excluded, there remains the question of what to do about it. The options include
Do nothing – it will probably fade into the background
In at least 4 out of 5 cases, tinnitus will fade into the background. Tbe noise may not nessarily go away, and, if you listen out for it, you will be able to hear it. But it won’t continue in the forefront of your attention. Like an air conditioner sound that you hear when you first enter a room, it will be noticeable for a while, but then disappears into the background, especially if something else occupies your attention.
Occupy the sound processing area of the brain with other sounds: Environmental Sound Therapy
One of the best ways to deal with tinnitus is to occupy the brain with some other sounds. The sounds should be acoustically complex, and pleasant to listen to. Suitable sounds include:
- waves on the beach
Recordings of these sounds can be obtained from Action on Hearing Loss, formerly known as the RNID (Royal National Institute for the Deaf). Their range of tinnitus relaxers is available to order at Action on Hearing Loss Shop – Tinnitus Relaxers
Use a hearing aid
If tinnitus is due to loss of hearing, a hearing aid can sometimes help. It is important to use an aid that does not block the ear canal. Modern fine tubing, open fit behind the ear aids are unobtrusive and more comfortable to wear than in-the-canal aids.
Sometimes, correcting the loss of hearing with a hearing aid can relieve tinnitus. It is important to use an open fit mould, as blocking the ear canal will probably make tinnitus worse.
Use a Wearable Noise Generator (WNG – formerly known as a tinnitus masker)
This option may be useful in severe tinnitus. WNG’s are normally provided by hearing therapists as part of the overall treatment for severe tinnitus. Wearable Noise Generators, combined with Cognitive Behavioural Therapy (CBT) is part of Tinnitus Retraining Therapy (TRT).
Prevention of further noise damage
Ear defenders should be worn to prevent further damage to the inner ear from noisy actities
It is important to prevent further damage to the delicate hair cells of the inner ear from excessive noise. Industrial hearing loss can result from continued exposure to noise levels in excess of 85 dB. Very loud machinery, such as a petrol chainsaw, can produce sound levels well in excess of 85dB and even short exposure can cause noise damage. Ear defenders should always be worn when using noisy equipment.
Severe tinnitus is due to the emotional reaction of the sufferer to the sound. That does not mean it is all in the mind. We all get emotional reactions to sounds. Think of the different reactions to
- a baby crying
- a wasp buzzing nearby
- a stirring trumpet call
It is normal to have emotional reactions to some sounds. The severity of tinnitus is largely due to the emotional reaction of the sufferer. The tinnitus is perceived as more annoying and intrusive, not necessarily louder.
How can we know how bad tinnitus is?
We have no objective way of measuring tinnitus severity. Like pain and suffering, we rely on the patient telling us what it feels like.
There is a standard questionnaire for tinnitus severity, developed on behalf of the British Association of Otorhinolaryngologists, known at the Tinnitus Handicap Inventory (THI).
Why some tinnitus becomes severe
Tinnitus is a side effect of evolution. To survive in the jungle, a vulnerable animal must focus attention on the quietest sounds of a predator approaching. Our brains evolved filters for deciding which kind of sounds are a threat.
When tinnitus becomes severe, it is probably because the sound is perceived as a threat. This causes the brain to focus in on the sound. It becomes amplified. There are good evolutionary survival reasons why this should happen. If you are in the jungle and vulnerable, you need to focus attention on the quietest sounds of a predator approaching. Such sounds induce fear. Hormones are released into the bloodstream. The nervous system is on high alert, preparing the body to fight, or run away. The sound processing areas of the brain are switched to threat detection mode.
Threat detection and false alarms
This passive infrared motion detector can be adjusted for sensitivity, to reduce the risk of false alarms. Our brains can also be adjusted for sensitivity to the false alarm of tinnitus. Unfortunately, it is not always quite as simple as turning down a dial.
If you have an electronic threat detection system fitted to your home, such as an intruder alarm, there will be some means of adjusting its sensitivity. An alarm that works on a vibration or motion sensor, if set too low, could be triggered by harmless things like the wind blowing against the window. An alarm that is extremely sensitive, on a hair trigger, will give far too many false alarms. It will be going off all the time, causing a nuisance. This is probably what happens in severe tinnitus. The home intruder alarm has a simple dial, to turn down its sensitivity. Unfortunately, our brains don’t come fitted with simple dials. But there are ways of adusting them. The aim is to reduce the sensitivity of the brain, so that it is only triggered by real threats, not the harmless noise of tinnitus.
Emotional areas of the brain affect sound processing
The sound processing areas of the brain, below the conscious level, are quite capable of suppressing some signals and enhancing others. They forward up to the conscious level a filtered, selected version of the soundscape.
Selective hearing – filtering out unimportant background noise
The silent air conditioner. It isn’t really silent. When you first walk into the room you will hear it. But its sound quickly disappears into the background. If you listen for it you can hear it again.
We all have selective hearing. For example, when you first walk into a room with an air conditioner, you will consciously hear the sound of the air conditioner. After a few minutes, you don’t hear it any more. The sound coming from the air conditioner has stayed exactly the same. But the sound processing area of your brain has filtered it out.
The sound processing area of your brain has filtered out the sound because it is not important. It is not a threat. The emotional areas of the brain, which direct your attention, have decided the air conditioner noise is not a threat. It is not important, so it can be suppresssed. You have become habituated to the sound and no longer hear it. But if someone draws your attention to it, you will hear it again.
Vincent van Gogh cut off his left ear before committing suicide. There is disagreement about whether he was suffering from tinnitus due to Meniere’s disease, but nearly all psychiatrists agree that he had severe clinical depression. The 1889 self portrait was done from a mirror, so it looks like the right ear, but was in fact the left.
Can tinnitus drive you mad? Can it lead to suicide? The answer is no – not on its own. But if you are clinically depressed, tinnitus can be the final straw.
Clinical depression and tinnitus
If you are depressed, then whatever is wrong with you – your back pain, your irritable bowel, your tinnitus – will feel ten times worse. Clinical depression is common – at least one in four will get it at some point in life. Tinnitus is also very common – nearly everyone will experience it. So, having both tinnitus and clinical depression is not unusual.
- Depressed patients cannot see the positive side of anything.
- They become obsessed with the negative.
- Endless, repetitive thoughts of hopelessness dominate and crush the spirit.
Nearly all reports of extreme tinnitus are in depressed patients. In severe clinical depression, no explanations, no rational arguments, will work. The mind is closed. The black dog is in the manger. Cognitive behavioural therapy is useless because the rational part of the mind is not accessible. Explaining tinnitus to a depressive is like explaining population control to a mother who has just seen her children murdered. Before any progress with tinnitus can be made, the depression must be treated.
Any doctor can diagnose depression. Treating depression is not something that most ENT specialists would undertake. Most cases of extreme tinnitus are due to depression. Usually, antidepressant drugs will be prescribed by a general practitioner or psychiatrist.
Tinnitus can make depression worse – negative thoughts feed off negative experiences. Depressed patients tend to wake in the early hours, when tinnitus will be at its worst. It is easy for a depressed patient to become convinced that tinnitus is the cause of all their problems. Combined ENT and psychiatric treatment may be needed.
Research needed on tinnitus – top ten priority questions
In September 2012, the James Lind Alliance, in partnership with the British Tinnitus Association, the National Institute for Health Research Nottingham Hearing Biomedical Research Unit and ENT UK, published a list of the top ten questions about tinnitus that need further research to provide answers. The priority for research was decided by a partnership of patients and professionals. The list of questions shows that we still have a lot to learn, especially about treatment – seven out of ten of the priority research questions were about treatment. The top ten research questions were:
- What management strategies are more effective than a usual model of audiological care in improving outcomes for people with tinnitus?
- Is Cognitive Behaviour Therapy (CBT), delivered by audiology professionals, effective for people with tinnitus? Here comparisons might be with usual audiological care or CBT delivered by a psychologist.
- What management strategies are more effective for improving tinnitus-related insomnia than a usual model of care?
- Do any of the various available complementary therapies provide improved outcome for people with tinnitus compared with a usual model of care?
- What type of digital hearing aid or amplification strategy provides the most effective tinnitus relief?
- What is the optimal set of guidelines for assessing children with tinnitus?
- How can tinnitus be effectively managed in people who are Deaf or who have a profound hearing loss?
- Are there different types of tinnitus and can they be explained by different mechanisms in the ear or brain?
- What is the link between tinnitus and hyperacusis (over-sensitivity to sounds)?
- Which medications have proven to be effective in tinnitus management compared with placebo?
Further reading / links
- Tune out Tinnitus – from Action on Hearing Loss / RNID
- Tinnitus Retraining Therapy: Implementing The Jastreboff Neurophysiological Model – by Jonathan Hazell, Tinnitus and Hyperacusis Centre, London UK
- British Tinnitus Association – Registered charity providing support and advice about tinnitus