Most people can relate to the experience of certain noises or sensations as being really unpleasant. For example, the thought of nails scratching down a blackboard can make the hairs on your arms to stand up, your teeth feel ‘on edge’ and the strong impulse to quickly cover your ears to stop the noise!
The term “misophonia” (hatred of sound) was first used in the early 2000’s to characterise the experience of an extreme emotional and physical response to certain ordinary, often repetitive, day to day sensory input. It is reported to occur in up to 20% of the population and equally in men and women. The input that evokes the most intense responses tends to be human created orofacial noises like breathing, swallowing, chewing, sniffing, throat clearing and lip smacking. Noises such as tapping and pen clicking have also been reported to be problematic. For people with misophonia, these experiences can evoke intense responses that may not seem in keeping with the circumstance such as disgust, irritation, anxiety, distress, anger and an overwhelming desire to remove themselves or remove the input from their environment.
Rather than misophonia being a hearing problem, it is now proposed to stem from attentional or emotional processing issues later in the brain’s auditory system. In examining brain activity while listening to a variety of sounds (including neutral, unpleasant and known misophonia triggers) Kumar et al (2017) found the following:
· the misophonia group rated the trigger sounds as more distressing than the other sounds.
· the research control group rated trigger and unpleasant sounds as similarly annoying.
These results support the theory that people with misophonia experience selective intolerance for trigger sounds (Kumar et al, 2017).
When hearing trigger sounds, Kumar also found people with misophonia demonstrate increased insula activation compared to controls, with higher levels of insula activity being correlated with greater reports of distress. The experience of trigger sounds for misophonics showed altered functional connectivity between the insula and other brain regions for attention and emotion. Given the insula plays an important role in internal awareness of body and emotional states, these findings suggest people with misophonia experience altered activation of interoceptive brain networks. Further, it has been proposed that this altered brain connectivity may have similarities to that which occurs in conditions like synesthesia, which is the experience of sensory crossovers (Edelstein et al, 2013)
A study by Kaufman et al (2022) showed people with misophonia have increased sensory responsiveness in the areas of adversive, hedonic, auditory and smell subscales. However they were not identified to have a sensory over-responsiveness type of sensory modulation dysfunction, which suggests that misophonia and SOR, while having some similarities, are actually separate conditions.
The intense adverse response to mouth noises (like chewing) are proposed to be due to heightened sensitivity in the connections between the auditory cortex and orofacial motor control areas. However a research study by Hansen et al (2022) has demonstrated strong connections also between brain regions associated with finger movement & sensation (ie tapping) and the insula.
Further research by Kumar et al in 2021 found that misophonics show increased activity between the auditory cortex and motor control areas related to the face, mouth and throat. Motor regions were not only strongly activated by trigger sounds (not other sounds), but also between visual and motor regions. These findings suggest that discrete visual cues/sensory input can also trigger misophonic responses, possibly due to an involuntary overactivation of the brain’s mirror system resulting in a perception that external trigger sounds are impacting on our bodies without our control.
Samermit et al (2022) investigated whether pairing of different visual stimuli with orofacial sounds (eg a visual of paper tearing paired with the sound of chewing) could alter the misophonic adverse response. Results indicated that this pairing increased the pleasantness of the sound, with the degree of pleasantness further improved if this pairing was presented first. This may indicate that the belief/prior about the sound source might impact on the level of adverse response. Kumar (2021) also suggests that some people can lessen symptom intensity by mimicking the action that generates the trigger sound, possibly by providing the brain with a prediction cue thus reducing novelty and increasing a sense of control.
This research further reflects the complexity of misophonia, including range of triggers and neurological pathways and networks involved, symptoms and functional implications.
The impact of misophonia can be widespread and result in people experiencing many challenges with a range of occupational and functional roles, for example:
· Eating meals with family & in public dining spaces (food courts, restaurants, hospital dining rooms)
· Studying in libraries and open classrooms
· Participating in examination conditions with a group of people
· Shared sleeping arrangements
· Using public transport
· Busy public entertainment venues (cinemas, theatres, concerts)
· Being around others in cold and flu season or being in a health clinic waiting rooms
Continued research and the findings discovered can help us better understand the mechanisms of misophonia and provide clues and recommendations to help in its management.
OTs can offer a range of different tools and strategies to assist people to better understand and manage their unique experience of misophonia, including:
· Education and support to increase people’s understanding and awareness of their experience of misophonia, including –
o specific sensory triggers
o resultant emotional and body responses
o the role that heightened interoceptive (internal body sensory) signals play in misophonia
o the impact of sensory overload on functioning and the importance of energy conservation principles including pacing, taking regular rest breaks, task modification & adaptation to reduce adverse sensory input.
· Sensory modulation strategies to help eliminate or dampen down the experience of the sensory trigger, such as –
o Earplugs such as ear defenders or ear loops
o Modify distance from/ proximity to the trigger (eg – position self further away)
o Adapt the task to alter engagement with the trigger (eg – sit somewhere else or an adjoining room to eat meals, consider a different activity for family connection time like an outdoor walk or board game instead of combined evening meal)
o Strategies to compete with the sensory trigger (use of masking sounds like music, nature sounds or white noise)
o Blue tooth headband for sleep
· Tailored sensory modulation strategies to help reduce stress and manage the emotion dysregulation that can be caused by the experience of misophonia, for example –
o Preferred sensory input
o Sensory routines embedded in day to day activities
· Address/update the brain’s prediction of the sensory input using an intervention combining sensory modulation, predictive processing strategies and sensory health principles
To learn more about Functional Brain Networks for Mental Health:
Sensory Modulation: Using a Sensory Lens with Clients (ticketspice.com)
To learn more about Predictive Processing for Mental Health:
Predictive Processing, Sensory Processing and Mental Health (ticketspice.com)
References
Edelstein M., Brang D., Rouw R., Ramachandran V. S. (2013). Misophonia: physiological investigations and case descriptions. Front. Hum. Neurosci. 7:296. 10.3389/fnhum.2013.00296
Hansen, H., Stefancin,P., Leber, A., Saygin, Z. (2022) Frontiers | Neural evidence for non-orofacial triggers in mild misophonia (frontiersin.org)
Hansen, H. A., Leber, A. B., and Saygin, Z. M. (2021). What sound sources trigger misophonia? Not just chewing and breathing. J. Clin. Psychol. 77, 2609–2625. doi: 10.1002/jclp.23196
Kaufman, A.,Weissman-Fogel. I., Rosenthal, Z., Kaplan Neeman, R., Bar-Shalita, T.(2022). Opening a window into the riddle of misophonia, sensory over-responsiveness, and pain. Frontiers in Neuroscience, https://doi.org//10.3389%2Ffnins.2022.907585
Kumar S, Tansley-Hancock O, Sedley W, Winston JS, Callaghan MF, Allen M, Cope TE, Gander PE, Bamiou DE, Griffiths TD (2017). The Brain Basis for Misophonia. Curr Biol. 2017 Feb 20;27(4):527-533. doi: 10.1016/j.cub.2016.12.048.
Kumar, S., Dheerendra, P., Erfanian, M., Benzaquén, E., Sedley, W., Gander, P., Lad, M., Bamiou, D., Griffiths, T. (2021) The motor basis for misophonia. Journal of Neuroscience. DOI: https://doi.org/10.1523/JNEUROSCI.0261-21.2021
Neurosciencenews.com (2017). The Brain Basis Of "Hatred of Sound": Misophonia - Neuroscience News
Samermit, P., Young, M., Allen, A.K., Trillo, H., Shankar, S., Klein, A., Kay, C., Mahzouni, G., Reddy, V., Hamilton, V., & Davidenko, N. (2022). Development and Evaluation of a Sound- Swapped Video (SSV) Database for Misophonia. Frontiers in Psychology, 13:890829. https://doi.org/10.3389/fpsyg.2022.890829
Samermit, P., Saal, J., & Davidenko, N. (2019). Cross-sensory stimuli modulate reactions to aversive sounds. Multisensory Research, 32(3), 197-213.