Hyperacusis

There is limited reliable data regarding the prevalence of significant hyperacusis cases. One online study proposed a rate as high as 9% among adults, although many experts in the field consider this figure to be inflated. A more cautious estimate indicates that approximately 2% of the adult population experiences some level of hyperacusis, with only a small fraction being severely affected. Hyperacusis frequently co-occurs with autism spectrum disorder (ASD) and other sensory conditions, as well as with tinnitus.

Hyperacusis manifests uniquely in individuals. For some, heightened sensitivity to sound doesn’t significantly disrupt their daily routines. However, others struggle to concentrate when exposed to certain sounds, experiencing tension or even anger. In severe cases, individuals may develop a fear of sounds, leading them to withdraw from daily activities to avoid auditory stimuli entirely. Unfortunately, this avoidance can exacerbate sensitivity in the auditory system.

The human auditory system possesses an impressive range, capable of detecting gentle sounds like the rustling of leaves and enduring loud environments such as music in a club. However, exposure to extreme sound levels, typically around 120dB or louder (equivalent to a jet plane taking off) can induce physical discomfort. Generally, we recognize when sounds become uncomfortably loud well before reaching this pain threshold, a point known as the maximum comfortable loudness. This threshold varies among individuals and can change based on mood and environmental context.

You may notice that certain sounds, like background radio noise, may be pleasing on one occasion but intrusive on another, particularly when feeling fatigued or stressed. Additionally, most people have specific sounds they find unpleasant regardless of volume, such as fingernails on a chalkboard or a dripping tap. For some individuals, alterations in sound tolerance are so severe that they significantly impact their daily lives.

Hyperacusis is a term encompassing all forms of altered sound tolerance, where individuals perceive even relatively modest environmental sounds as loud, intrusive, and sometimes painful. Additional terms are used to describe various types of hearing sensitivity:

Phonophobia refers to a fear or aversion to specific sounds, which can vary from person to person and may include sounds like hand dryers, fireworks, or the scraping of cutlery on a plate.

Misophonia, on the other hand, describes an intense dislike or repulsion towards particular sounds, often those generated by others, such as chewing.

Recruitment is a distinct type of altered sound tolerance found in individuals with hearing loss. People experiencing recruitment may request others to speak up, only to then perceive the increased volume as shouting. This phenomenon occurs when the auditory system quickly transitions from perceiving too little sound to perceiving too much.

Certain medical conditions can present hyperacusis as a symptom, underscoring the importance of consulting with your GP. Medical conditions associated with altered sound tolerance include migraine, head injury, Lyme disease, William’s syndrome, Bell’s palsy, and sometimes, hyperacusis can manifest after specific types of ear surgery.

Exposure to sudden loud noises can also trigger hyperacusis, while in some cases, the onset appears to be associated with negative life events. However, for many individuals, no clear cause can be identified.

For others, hyperacusis may be linked to sensory-sensitive conditions such as autism spectrum disorder (ASD) or tinnitus.

Various theories exist regarding the mechanisms underlying hyperacusis, all suggesting an association with increased sensitivity or auditory gain in the central auditory system—the hearing pathways in the brain. This sensitivity can be influenced by mood.

While there is indeed a significant overlap between tinnitus and hyperacusis—many individuals with tinnitus also experience hyperacusis, and vice versa, it’s essential to note that not everyone with one condition will develop the other. Many individuals have either tinnitus or hyperacusis without experiencing the other. Thus, the presence of one condition does not necessarily indicate the development of the other.

Due to the rarity of significant hyperacusis in adults, most general practitioners may have limited familiarity with it. Therefore, a formal investigation is typically conducted by an ear, nose, and throat (ENT) surgeon or an audiovestibular physician.

During the examination, the specialist will inquire about your sound tolerance, including when and how the symptoms started. They will also ask about any other illnesses or circumstances concurrent with the onset of symptoms, as well as how you manage day-to-day activities and any changes since the onset. Additionally, you can expect questions about hearing loss, noise exposure, and tinnitus.

You may be asked to complete questionnaires assessing your general mood, hyperacusis symptoms, and quality of life. These questionnaires help to provide insight into your situation and may guide therapy while monitoring its effectiveness.

Furthermore, your ears will be examined, and a hearing test will likely be conducted. Some doctors may recommend additional tests, which will be explained to you during the examination. If you have any concerns about the tests, don’t hesitate to discuss them with your specialist.

For many individuals, hyperacusis is not significantly troublesome, and in such cases, simple explanation and reassurance can suffice to effectively manage the condition.

However, for those experiencing more severe symptoms, referral for therapy may be recommended. Therapy is typically provided within an audiology clinic by professionals who also work with individuals dealing with tinnitus. If hyperacusis is a symptom of an underlying medical condition, treatment for that condition will be pursued concurrently.

During therapy sessions, the therapist will assess how hyperacusis affects the individual and work collaboratively to explore strategies to mitigate its impact on daily life. Many people with hyperacusis tend to withdraw from sound, so therapists often employ techniques to gradually reintroduce sound into their lives. This approach, known as sound therapy, may involve the use of ear-level devices or bedside sound generators, often using white noise, which resembles a rushing or “shhh” sound.

Alternatively, Cognitive Behavioural Therapy (CBT) can be utilised to identify factors that exacerbate or alleviate hyperacusis symptoms. Through CBT, individuals learn more effective ways to manage their condition, thereby reducing its impact on their lives.