Tinnitus

Facts About Tinnitus

Tinnitus is the perception of sound without an external sound source that lasts at least 5 minutes and occurs at least every week
Tinnitus can be perceived in one ear, both ears, and in the head. Some people perceive it as an external sound.
Tinnitus can be:
- subjective: neural signals interpreted by the brain as sound(s)
- objective: somatosounds (sounds produced within the body)
Tinnitus can be constant or intermittent
Tinnitus can be a single sound or a complex series of sounds
Tinnitus is heard by >90% of the population when in extreme silence
About 30% of the population become aware of tinnitus
15 to 20% report constant tinnitus
About 2% develop tinnitus disorder. This is a severe form of tinnitus associated with high levels of emotional distress.

Tinnitus is often considered to be a single condition, but is more accurately described as a spectrum disorder, with significant variability between individuals in onset, cause, the nature of the tinnitus sound(s), severity, persistence and reactivity.

Subjective tinnitus

Subjective tinnitus is the result of neurological changes in the central auditory system and emerges in the cochlear nucleus in the brain stem – the first step in the auditory processing pathway.

This is the most common type of tinnitus and is most often triggered by reduced hearing. This may be due to a range of causes: noise damage, age-related acquired hearing loss, sudden hearing loss, ototoxicity or other medical conditions affecting the ear/hearing. Because tinnitus is a neurological phenomenon, it can persist even if a hearing loss is temporary.

Tinnitus can develop in people with measurably normal hearing. Stress has been found to trigger tinnitus without an associated hearing loss (Kim, Y.L. et al, 2024).

Somatosensory tinnitus

Head, neck and jaw muscular movements are processed in the cochlear nucleus – the same region in the brain where tinnitus emerges. Neuroscientist Dr Susan Shore has identified the connections between the somatosensory and auditory systems in the cochlear nucleus and has shown that head/neck/jaw movements can influence tinnitus. This tinnitus modulation is reported by about two thirds of tinnitus patients, although Dr Shore considers this potentially occurs in every tinnitus patient but may not be noticeable.

Muscular tension or dysfunction in the head/neck/jaw such as stress-related jaw clenching, tooth grinding, TMJ dysfunction, neck problems and tensor tympani syndrome (TTS) can cause or aggravate tinnitus at this neurological level (Michiels S et al 2018). This muscular tension/dysfunction can affect one side only or more strongly, and can be a cause for tinnitus being heard more strongly, or only, in one ear or on one side of the head. However, for patients with significant tinnitus asymmetry, all possible causes should be medically investigated.

Tinnitus habituation

Most people with tinnitus will spontaneously habituate to their tinnitus over time. So for most people, the initial experience of tinnitus is often the most difficult time.

For a satisfactory level of habituation to be achieved, some degree of adjustment to and acceptance of the tinnitus is needed. This is based on a subconscious evaluation of tinnitus as a safe sound, to enable the tinnitus to become integrated into the concept of a normally functioning sense of ‘self’, both physiologically and psychologically.

Tinnitus Disorder

Tinnitus onset, persistence and severity can be highly distressing and become traumatic, tapping into the primal parts of the brain where sounds (including tinnitus) are evaluated to identify potential threats to one’s safety, wellbeing and survival. An intense tinnitus reaction can then be involuntarily maintained or enhanced, becoming a tinnitus disorder. Ongoing tinnitus reactivity or tinnitus spikes i.e. episodes of tinnitus aggravation are common.

Non-auditory factors have been shown to aggravate tinnitus, with abnormal activity detected in the subconscious parts of the brain where we process threat (the limbic and autonomic systems), enhancing not just the emotional and neurophysiological impact, but the volume and prominence of tinnitus.

Tinnitus awareness, prominence and volume are also typically affected by stress, depression, anxiety and fatigue. Studies indicate that stress, derived from causes unrelated to the tinnitus (such as pre-existing depression, anxiety), as well as stress associated with the experience of tinnitus, can cause significant tinnitus exacerbation and limit spontaneous tinnitus habituation. Stress associated with anxiety, depression, fatigue etc can be responsible for tinnitus spikes. So there is a two-way relationship: tinnitus causes stress; stress can cause/enhance tinnitus.

Tinnitus disorder is associated with reduced ability to think clearly (cognitive dysfunction) and autonomic arousal (increased sweating, elevated heart rate, elevated blood pressure) affecting the whole body, leading to changes in behaviour and reduced ability to function.

Apart from these psychological and neurological effects of tinnitus disorder, there will be physical consequences - stress is held in the body.

Models of tinnitus disorder

There are a number of models of tinnitus distress that explore the interaction between the auditory and psychological pathways and networks in the brain. These include the Neurophysiological model (Jastreboff P, 1990); the Cognitive – Behavioural model (McKenna L et al, 2014); the Fear-avoidance model (Cima R et al, 2011); the Triple Network Model (De Ridder D et al, 2022). These models have been well documented elsewhere.

Tinnitus: Placebo and Nocebo

The mindset (beliefs, expectations, safety/lack of safety) and context are powerful in reinforcing a positive or negative subconscious response to a stimulus or treatment.

The placebo/nocebo effect is more than positive or negative thinking, it is a subconscious phenomenon affecting symptoms modulated by the brain, including the perception of pain and the reaction to tinnitus.

A sense of safety induced by a placebo can trigger the brain's natural pain-relief mechanisms, reducing the perception of pain signals from nociceptors. Tinnitus is known to be highly responsive to the placebo benefit of any positively perceived stimulus or treatment. A historical study, which continues to be widely cited, evaluating the placebo effect in tinnitus reported that up to 40% of patients experienced greater than 25% improvement in their symptoms (Duckert et al 1984). The internet is full of tinnitus “treatments” or “cures” that may have been effective for some individuals due to placebo.

We know from chronic pain research that the limbic system will become protective towards stimuli perceived (rightly or wrongly) as a potential threat, and that a nocebo effect occurs when a perceived lack of safety aggravates pain.

A severe reaction to tinnitus will create a powerful subconscious protective drive to ensure the tinnitus will not be aggravated by any external factors, such as sounds, medications, food, drinks etc, perceived (rightly or wrongly) as potentially aggravating the tinnitus or damaging the hearing.

The placebo/nocebo effect explains why some people find e.g. cannabis, psilocybin microdosing and alcohol beneficial while others find these will aggravate their tinnitus.

For some, the combined effects of a belief/expectation of harm + heightened levels of tinnitus vigilance + subconscious protectiveness towards threatening stimuli can trigger or aggravate tinnitus spikes due to a nocebo effect. This can become further exacerbated by the somatosensory influence on tinnitus of heightened levels of stress held in the jaw muscles.

This subconscious protectiveness can become triggered by daily exposure to loud, unavoidable and unpredictable sounds – setting the scene for hyperacusis development.

Contemporary best practice for tinnitus treatment

In recent years, experts are moving away from boxing tinnitus into generalised subtypes and siloed treatment categories. It is more effective to evaluate and treat at an individual, personalised level the complex factors contributing to each patient’s tinnitus experience. This is increasingly recognised within the broader tinnitus neuroscientific and clinical community with a personalised, holistic and whole body approach promoted as best practice at recent international tinnitus conferences. The personalised approach of CBT and other psychological treatments may be a factor behind their success.

There is an overlap in the models of tinnitus disorder. Elements of all the tinnitus models and their recommended treatment approaches can be combined and triaged to treat each patient’s unique auditory, psychological and somatic (muscular) brain and body pathways underpinning their tinnitus experience. TTS symptoms should not be overlooked, raising anxiety with regards to ear health and potentially aggravating tinnitus: one or more symptoms consistent with TTS have been documented in 68% of patients with severe tinnitus (Westcott et al 2013).

Treatments which target the site of tinnitus emergence in the brain hold promise and can harness the powerful effects of placebo – but they need to be part of a personalised, broader approach treating the complex brain and body regions which contribute to the tinnitus experience, and lead to tinnitus disorder.

While a cure remains elusive, the aim of best practice tinnitus therapy is for the tinnitus to become perceived in the brain as a safe, unimportant sound allowing habituation to spontaneously take place.

Once patients understand how the brain processes potentially threatening sounds, including tinnitus, and understand in depth the factors inhibiting their progress towards tinnitus habituation, they have the potential to reverse a strong tinnitus reaction. If a patient doesn’t know their pathways or doesn’t understand the powerful effect of nocebo or doesn’t understand TTS, they don’t know what/why/how they need to unravel in the treatment process. This understanding provides reassurance, insight, can be highly therapeutic at stopping further tinnitus escalation and limiting tinnitus reactivity, and allows targeted, personalised treatment strategies and a holistic approach.

So the first important steps in a tinnitus treatment process should be a comprehensive hearing assessment, followed by analysis with an experienced clinician to explore, reveal, evaluate and explain. The information provided needs to be free of inadvertently stirring up additional threat. Effective targeted multidisciplinary treatment, combining elements of all models and their approaches, can then be carried out.

With regards to tinnitus-related stress, consider assessment/treatment of any muscular tension held in the jaw region. Body-based somatic therapies can change the emotional, behavioural, and cognitive effects of tinnitus by combining physical somatic interventions with a cognitive element.