A to Z of tinnitus
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A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Acoustic shock is the name for pain, tinnitus, balance disturbance and phobic symptoms following exposure to sudden, intense, unexpected noise. “Any temporary or permanent disturbance of the functioning of the ear, or of the nervous system, which may be caused to the user of a telephone earphone by a sudden sharp rise in the acoustic pressure produced by it.” (International Telecommunications Union European Transmission Standards Institute). “Acoustic shock is an adverse response to an acoustic incident resulting in alteration of auditory function.” (Acoustic Safety ).
Acoustic nerve, also known as the vestibulocochlear nerve or auditory nerve, is the eighth of twelve cranial nerves and connects the inner ear to the brain. It is concerned with hearing, balance and sensing the position of the head and consequently splits in two; one part linking to the cochlear, the other to the vestibular or balance sensors (the semicircular canals and the Otoliths), hence the derivation 'vestibulocochlear nerve'.
Acupuncture is the practice of a trained practitioner sticking sharp needles in a person with the counter-intuitive intention of making them feel better. It is a Complementary Therapy. There is some evidence that it may be effective against a range of conditions, including tinnitus. It is available in some NHS areas, generally via the Physiotherapy department.
Audiogram is a graph of sound frequency against Hearing Level (in dB). It normally covers the frequencies between about 100Hz and 8 KHz. The definition of normal changes with age because hearing degrades naturally as people get older. Initially, hearing may extend from 20 Hz to 20 KHz. The critical frequencies are the ‘speech frequencies’, about 500Hz – 5 KHz; hearing loss at 18KHz may not be noticeable to most people but loss at 3 KHz almost certainly will be. Most hearing aids operate to improve sound perception at the speech frequencies and don’t operate above 8KHz (this reduced range increases battery life).
Benign refers to a condition, tumor, or growth which is not cancerous and will not spread to other parts of the body. Benign tumors normally grow slowly. In general, a benign tumor or condition is not harmful although if it is big enough, it may press on nearby blood vessels, nerves, or organs and thus cause problems.
Bruits is the term for the unusual sound that blood makes when it rushes past an obstruction in an artery from the French bruire, "to roar."
chronic illness is one which persists for a considerable time.
cochlea is the ‘microphone part’ of the inner ear. The name is from the Latin for snail and refers to its coiled shape; the cochlea is coiled in most mammals.
Cognitive Behavioural Therapy is a psychotherapy based on modifying cognitions, assumptions, beliefs and behaviors, with the aim of influencing disturbed emotions. The general approach developed out of behavior modification, Cognitive Therapy and Rational Emotive Behavior Therapy, and has become widely used to treat various kinds of neurosis and psychopathology, including mood disorders and anxiety disorders. The particular therapeutic techniques vary according to the particular kind of client or issue, but commonly include keeping a diary of significant events and associated feelings, thoughts and behaviors; questioning and testing cognitions, assumptions, evaluations and beliefs that might be unhelpful and unrealistic; gradually facing activities which may have been avoided; and trying out new ways of behaving and reacting. Relaxation and distraction techniques are also commonly included. CBT is widely accepted as an evidence and empirically based, cost-effective psychotherapy for many disorders and psychological problems. It is sometimes used with groups of people as well as individuals, and the techniques are also commonly adapted for self-help manuals and, increasingly, for self-help software packages. (from wikipedia)
Complementary Therapies or ‘Alternative therapies’ are treatments which lie on the edge of or outside conventional medicine. This may be because it is difficult to conduct scientific trials on particular treatments, because of an unusual belief system associated with the treatment or some other reason. Some, previously controversial complementary therapies are now more accepted, such as acupuncture and hypnosis.
Computational models of Tinnitus refer to recent new modeling of the auditory system as an information system. Some, for instance Parra’s work, offer insights into possible new tinnitus treatments.
decibel (dB) One tenth of a Bel (B). The Bel was invented by engineers from the Bell Telephone Laboratory. It is a rather big unit, so the decibel is more common. The definition of the decibel uses base-10 logarithms to easily represent a large range of sound. The decibel is commonly used in acoustics to quantify sound levels relative to some 0 dB reference. The reference level is typically set at the threshold of human perception. The ear is sensitive to a wide range of sound intensities or pressures and a logarithmic scale such as the decibel is ideal for measuring this (also, by coincidence the ear is not equally sensitive to all frequencies and the decibel again nicely copes with this). An increase of 3 dB corresponds to an approximate doubling of power so for instance two 70dB noises added together equals 73 dB not 140 dB.
dorsal cochlear nucleus (DCN)
eardrum
EEG
ENT
epidemiology
Epley manoeuvre; provides help for dizziness generated by ’misplaced’ crystals or debris in one balance organ, which can be cured by repositional movements if they do not stop by themselves:
To be performed by your therapist: To reposition the crystals the therapist will perform what is called an Epley manoeuvre on you. The therapist will ask you to sit on a bench with your back to them. You will then turn your head 45 degrees to the left/right and lie down quickly allowing your head to hang over the end of the bench, your therapist will hold your head in this position and ask you to keep your eyes open and tell them if you're experiencing any spinning. Once the spinning stops (and it will) you will then turn your head slowly to face the opposite side and wait again until any sensation stops. Then you turn your whole body so you're on your side and looking at the floor, there is another pause until the spinning stops and then you sit up quickly, with your “chin on the chest”. Your therapist will be holding your head the whole time and you are not left alone, the whole process only takes 2-4 minutes so, although it is frightening, it will be over quickly.
Brant-Daroff exercise – to be done at home, 2 or 3 times a day: You sit on the edge of your bed and turn your head 45 degrees to the left or right (opposite to the side producing the symptoms). Then keeping your head in this position lie down quickly on your side (the side that produces the symptoms), you'll be looking at the top of the wall and the back of your head will be on the bed. Then when the dizziness passes turn over as quickly as possible to the other side. If you again feel dizzy, lie still until the dizziness has disappeared, then turn over as quickly as possible to the initial position! You may need to repeat this until it does not provoke any dizziness. It's best to do this without any duvet or pillows on the bed so you're lying totally flat.
eustachian tube
fMRI see MRI.
Gaze modulation of tinnitus see Somatically modulated tinnitus.
Gingko biloba
Habituation
Hair cells are in the cochlear. They come in two types, inner and outer hair cells, and change sound energy into electrical nerve energy. The outer hair cells are now believed to be mainly involved in mechanically amplifying the sound signal, which the inner hair cells then convert to electrical nerve signals. It used to be thought most tinnitus originated in the damage to hair cells, but, whilst noise damage can produce tinnitus it is now thought that the site of most ‘troublesome tinnitus’ lies within the brain.
Hyperacusis is an over-sensitivity to certain frequency ranges of sound. It is characterized by difficulty tolerating everyday sounds, some of which may be perceived as unpleasantly loud by that person but not to others. Studies have found that between 40% (Bartnik et al, 1990) and 79% (Dauman, Bouscou-Daure, 2005) of those with tinnitus also have hyperacusis. One definition is "consistently exaggerated or inappropriate responses or complaints to sounds that are neither intrinsicallly threatening nor uncomfortably loud to a typical person" (Klein, 1990). It has also been defined as an unusual tolerance to ordinary sounds or an abnormal reaction to sound.
Hypnotherapy
Inhibition
Jastreboff Neurophysiological Model and the Habituation Model (often called the Psychological Model) of tinnitus.
Labyrinthectomy
Lidocaine (also known as Lignocaine)
Limbic system
matching tinnitus is the matching of the perceived tinnitus level with an external sound source.
masking
Misophonia (coined by Jastrebof and Hazell) is the dislike of sound. Another term used may be 'noise annoyance'. Phonophobia is a subset of mispohonia in which fear is the dominant emotion.
MRI is a Magnetic Resonance Imaging system. It uses superconducting magnets to force the nuclei of atoms in the patient to align in particular directions, like a compass lining up north/south. The patient is then exposed to specific radio waves, which flips some of the nuclei out of balance. As the nuclei re-align they send out signals of their own, which form the image. Typical magnetic fields are 0.2 to 3 Tesla, the stronger the field the better the resolution achievable and the more expensive the machine. Noise levels are high, up to 120dB (a pneumatic drill at close range), because of the mechanical stresses in the magnet. Using it on those with tinnitus requires careful preparation and hearing protectors would normally be mandated. MRI scans do not expose a patient to damaging radiation, unlike x-ray CT scanners, and can therefore be used repeatedly if necessary. They are particularly useful for imaging soft tissues, such as tumours. Functional MRI (fMRI) involves making repeated scans, typically every 2 seconds, with the scanner tuned to detect the Blood Oxygen Level Dependent effect (BOLD) which is a way of assessing the neural activity of the brain, based on the uptake of oxygen from haemoglobin in the blood vessels (the two forms of haemoglobin, with and without oxygen attached, have different magnetic properties). Skilful interpretation is necessary and there is still some debate about what is actually being measured. Below are a typical MRI scan and an fMRI scan of a human head.
neurone
neurophysiological model
noise measurement (add scale)
Objective tinnitus
Otology is a branch of biomedicine which studies normal and pathological anatomy and physiology of the ear (hearing and vestibular sensory systems and related structures and functions) as well as its diseases, diagnosis and treatment.
otosclerosis is stiffening of the tiny bones (hammer, anvil, stapes) which transmit sound from the eardrum to the sound-detecting organ, the cochlea.
phantom itch is the term used for the sensation some amputees have, when they are able to feel sensation in their missing limb (specifically, itching). Tinnitus has ben compared to this, since both are the perception of a sensation without a real input.
Phonophobia is literally a "fear of sounds", particularly sudden and unexpected ones. A phobia is generally considered to be a fear that an individual realises is unreasonable, however, this is not always so in cases of hyperacusis.
Placebo effect
plasticity of the brain
presbycusis (age-associated hearing loss)
Pulsatile tinnitus is an uncommon otological symptom. Objective pulsatile tinnitus has numerous causes, including benign intracranial hypertension, glomus tumours and atherosclerotic carotid artery disease. History and physical examination can give important information as to the underlying diagnosis. Radiographic evaluation is essential in all patients with pulsatile tinnitus. Many patients have a treatable underlying condition.
Pure Tone Audiometry
Recruitment is an unusually rapid increase in loudness with increase in stimulus level. It is asociated with cochlear hearing loss, specifically with outer hair cell dysfunction (Moore, 1998). This results in reduced auditory dynamic range, which may be a challenge when fitting a hearing aid. As it is generally believed to be caused by a physical mechanism in the cochlear it is unlikely to be affected by emotional states.
rTMS repetitive Transcranial Magnetic Stimulation, see TMS
Severity of tinnitus This scale is reproduced from the study: Guidelines For the Grading of Tinnitus Severity - The results of a working group commissioned by the British Association of Otolaryngologists, Head and Neck Surgeons, 1999. Members of the group were: Chairman - Andrew McCombe MD FRCS (ORL), Consultant ENT Surgeon, , . David Baguley - MSc MBA Audiological Scientist, Cambridge, Ross Coles- MB FRCP(Ed) DLO Audiological Physician, Nottingham, Laurence McKenna PhD Neuro-psychologist, London, Catherene McKinney BSc Audiological Scientist Guy's and St. Thomas' Hospital Trust, Audiology Dept., St. Thomas' Hospital, Lambeth Palace Road, London SE1 7EH, Paul Windle-Taylor- MA, FRCS, MBA, Consultant Otolaryngologist, Derriford Hospital, Plymouth, Devon)
Grade 1 - slight - (Tinnitus Handicap Inventory score (THI) 0-16) - Only heard in quiet environment, very easily masked. No interference with sleep or daily activities. This grading should cover most people who are experiencing but are not troubled by tinnitus.
Grade 2 - mild - (THI 18-36) - Easily masked by environmental sounds and easily forgotten with activities. May occasionally interfere with sleep but not daily activities.
Grade 3 - moderate - (THI 38-56) - May be noticed even in the presence of background or environmental noise although daily activities may still be performed. Less noticeable when concentrating. Not infrequently interferes with sleep and quiet activities.
The majority of people suffering tinnitus should fall into Grades 2 & 3.
Grade 4 - severe - (THI 56-100) - Almost always heard, rarely if ever masked. Leads to disturbed sleep pattern and can interfere with ability to carry out normal daily activities. Quiet activities adversely affected. There should be documentary evidence of the complaint being brought to the general (or some other) medical practitioner (prior to any medico-legal claim). Hearing loss is likely to be present but its presence is not essential. Given the epidemiological data, grading in this group should be uncommon.
Grade 5 - catastrophic - (THI 56-100) - All tinnitus symptoms at level of severe or worse. Should be documented evidence of medical consultation. Hearing loss is likely to be present but its presence is not essential. Associated psychological pathology is likely to be found in hospital or general practitioner records. Given the epidemiological data, grading in this group should be extremely rare.
Sensorineural hearing loss is a type of hearing loss in which the root cause is in the vestibulocochlear nerve, the inner ear, or the central processing areas of the brain.
Sleep Patterns change as people age, older people need much less sleep than teenagers and tend to wake several times during the night. Generally when people say they are woken by their tinnitus they have woken as part of their normal sleeping pattern but have then been kept awake by their tinnitus and remembered this in the morning, where normally the waking would be forgotten about. Trials have shown that it is possible to go without sleep for very long periods without harm and lack of sleep caused by tinnitus, although distressing is unlikely to be harmful.
somatically modulated tinnitus (‘somatic’ refers to the body) is tinnitus that can be affected by physical movement. Research indicates that 80% of people with troublesome tinnitus find that it is modulated by somatic input from the head or neck and in 60% of people without tinnitus, some tinnitus can be transiently induced by such movements (R Levine, MD, Massachusetts Eye and Ear Infirmary). Somatic modulation of tinnitus thus appears to be a very common phenomenon, and the implication is that some neural pathway connecting somatic sensation with hearing is present in humans.
sound enrichment
subjective tinnitus
Sudden hearing loss (SHL) is a medical emergency for which definitive diagnosis and treatment is still largely unknown.
Symptom in the medical sense is a sensation or change experienced by an individual. Tinnitus is a symptom.
THI or Tinnitus Handicap Inventory (developed by Kuk, Tyler, Russell and Jordan) is one of the two main questionnaires used to assess tinnitus severity. It takes about 20 minutes to complete and mark the 25 self-assessment questions. It is helpful to have a qualified person assist with explanation . It is non-copyright and may be freely reproduced, originally developed for the it works fine in the . Comparable to the Tinnitus Questionnaire, it gives similar results.
Tinnitus is the latin for ringing
Tinnitus Questionnaires see THI and TQ
TMDS Trans mandibular
tonotopic
TMS Transcranial Magnetic Stimulation (TMS) is a procedure to excite brain cells (neurons) using a ‘figure of eight’ electromagnet held over a patient’s head. Typical magnetic field strengths used are about 2 tesla (the Earth’s magnetic field is about 50,000 times less powerful).
When the magnetic field is modulated, with frequencies of around 1 Hz, the process is known as repetitive transcranial magnetic stimulation (rTMS). In rTMS trials, stimuli may be applied to the same brain area for a few minutes a day, over the course of a few weeks. Repetitive TMS can be used to study how the brain organises different functions such as language, memory, vision, or attention. It also seems capable of changing the activity in a brain area beyond the duration of the rTMS application itself. In other words, it seems possible to modify some brain cell behaviour for a period of minutes, hours, days or even weeks after a period of rTMS treatment. This therapeutic potential is still being studied.
The idea behind rTMS is that different areas of the brain are sluggish or overactive. In people with depression, for example, the left prefrontal cortex is less active than in people without depression. In people with anxiety disorders, the right prefrontal cortex is more active than in people without anxiety disorders. More technically, rTMS alters the biochemistry and firing patterns of neurons in the cortex, the part of the brain nearest the surface. Research indicates that the treatment affects gene activity, levels of neurotransmitters such as serotonin and dopamine, and the formation of proteins important for cellular signalling. This stimulation also seems to affect connected brain regions, deeper in the brain. There is an increasing body of evidence which indicates that at least some forms of tinnitus are generated within the brain and may respond to techniques intended to modify brain cell behaviour.
One of the problems with rTMS has been in identifying the correct position for the coils, relative to the target brain area. A procedure known as neuro-navigation is being developed, where a brain imaging tool such as functional magnetic resonance imaging (fMRI) is used to identify the relevant areas of the brain and guide the rTMS coil into an effective position.
There is increasing evidence from a growing amount of studies that low frequency rTMS can result in reduction of tinnitus sensation in some patients. However treatment results are characterised by high variability between individuals and only moderate effect sizes. Additionally, the mechanisms by which rTMS effects are produced are far from being entirely understood. Also, the long-term risks of rTMS are not known although the limited data available from repeated application of high intensity magnetic fields to humans, such as in magnetic resonance imaging, do not suggest that they are significant.
In summary rTMS using neuro-navigation has the potential to provide some particular subgroups of tinnitus sufferers with some relief. However, much more work is required before it becomes a routine medical treatment, if ever.
Tinnitus Retraining Therapy (TRT )
TQ or Tinnitus Questionnaire (developed by Hallam, Jakes and Hinchcliffe) is one of the two main questionnaires used to assess tinnitus severity. It takes about 25 minutes to complete and is best done with a qualified person to assist. It is copyright and should not be photocopied or otherwise poached. Comparable to the Tinnitus Handicap Inventory, it gives similar results.
Vestibular Schwannoma (also known as benign acoustic neuroma)
White noise is a sound composed of random noise, like the 'hissing' of an off-tune radio. It contains all frequencies and has an equal power at any frequency (i.e. is proportional to the frequency, f). It is similar to white light (which contains all visible light frequencies, i.e. all colours). There are a number of other ‘colours’ of sound: Pink noise (1/f noise) which sounds more natural, rather like the wind. Grey noise is random noise adjusted to take account of the human ear, giving the listener the perception that it is equally loud at all frequencies (in contrast to white noise which is equally loud at all frequencies but not perceived as such because of the natural bias of the human ear).
Voxel is the smallest measurable volume (Volume Pixel), similar to pixel in a 2-dimensional photograph or computer screen. Voxel size varies widely, depending on the imaging system used.
wax earwax
Zwicker tone is an auditory illusion, discovered in 1964 by at the Bell Laboratories. A broad-band noise but with a group of missing frequencies is played for a few seconds. When the noise is switched off suddenly so there is complete silence, most listeners hear a faint tone for a few seconds, the pitch of which corresponds to the missing frequency band of the previous noise. It can be thought of as a form of short-term tinnitus but it’s origin is unclear. Recent mathematical models can explain the phenomena as part of a general model of tinnitus.
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