Few know this about me, but ever since I was 14 years old, I have felt near-uncontrollable anger in reaction to the sound of gum-chewing. I don’t know why this is, just when it began. It is hard to explain to other people and has impacted my social life and some everyday interactions. I recently found that there are some people with a similar problem. It’s referred to as misophonia and may have neurological roots. It’s not well-known or understood because it’s a relatively new topic in psychology. It is not yet in the Diagnostic and Statistical Manual (DSM), the text which all psychiatric professionals use to make diagnoses. As the DSM is only published every ten years and researchers have to lobby to have any new diagnosis included in the manual, it could be a while before misophonia is an officially-recognized problem.
The first academic mention of this disorder was in 2000 and it was termed Selective Sound Sensitivity Syndrome. It has been referred to as "misophonia" since 2001 when the term was coined by Margaret and Pawel Jastreboff. The first real experiment related to misophonia was not conducted until 2013, as the Jastreboffs did not have the funding to conduct research and only theorized about the condition.
The word “misophonia” literally means “hatred of sound” but that is not an adequate description of the condition. Schröder et al. (2013) define it as “a similar pattern of symptoms in which an auditory or visual stimulus provoked an immediate aversive physical reaction with anger, disgust, and impulsive aggression. The intensity of these emotions caused subsequent obsessions with the cue, avoidance, and social dysfunctioning with intense suffering.” The key thing here is the type of auditory and visual stimuli. In various articles on misophonia, these stimuli are referred to as “trigger sounds”. While sounds like nails on a chalkboard or a siren are universally unpleasant and provoke a reaction, misophonic trigger sounds are everyday noises. Most are made by other humans and most are repetitive. Commonly-reported trigger sounds are chewing sounds, loud breathing/nose sounds such as coughing or throat-clearing, and finger/hand sounds such as typing or pen-clicking. Others mentioned include sniffing, nose-blowing, humming, crinkling bags or other rustling sounds, and windshield wipers. Some people also reported related visual triggers, such as repetitive leg rocking, but research focuses mainly on auditory triggers.
The first study on this topic was done in 2013 by Schröder et al. in Amsterdam. 42 participants were interviewed by psychiatrists and were screened using adapted versions of common psychological questionnaires. Since Schröder et al. are researchers who usually focus on obsessive-compulsive disorder, they were particularly interested in any possible connection between OCD and misophonia. In their study, participants described concerns over losing self-control when lashing out at a person making a trigger noise. All participants coped in similar ways, with the use of headsets, producing “anti-sounds” or mimicking sounds, or by avoiding social situations. Across the board, participants reported emotional and physical reactions to these sounds very similarly, with intense feelings of “discomfort, anger, or disgust”. When looking at the questionnaire results, the researchers found that their participants had higher rates of depressive and anxiety symptoms as well as psychoneuroticism than the general population. Notably, 52.4% of participants met the diagnostic criteria for obsessive-compulsive personality disorder (OCPD) - which is different from OCD, of which most are aware. Schröder et al. argue that misophonia is its own disorder separate from OCD with diagnostic criteria that they define in the article with a list of six conditions, as seen in the image below.
A few months after the Schröder et al. study was published, another study by Edelstein et al. was published. It consisted of an interview as well as an experiment measuring participants’ physiological responses to trigger sounds alone, visual triggers alone, and an audio-visual combination. The interviews produced results very similar to those in the Schröder et al. study, wherein participants reported similar symptoms, trigger sounds, physical responses, and coping mechanisms. The participants also reported not being bothered by those same trigger sounds if they were the one producing the sound or if it was produced by an animal or young child, as they do not have the same control over their actions or social awareness as adult humans. The second part of this study measured the difference in skin conductance response in people with misophonia and people without it. The results show there was a notable difference in physiological response between the two groups. They also found that the audio alone produced a greater response than visual alone or auditory-visual.
A third study in 2017 was conducted by Kumar et al. using fMRI, blood-oxygen-level-dependent measurements, galvanic skin response measurements, heart rate measurements, behavioral observations, and brain structural measurements in two groups - those with misophonia and those without it. fMRI data was taken while participants listened to recordings of three types of sounds: trigger sounds, neutral sounds like rain, and universally unpleasant sounds like a wailing baby. The fMRI data showed more activation in the anterior insular cortex (AIC) of the misophonic group in reaction to trigger sounds and reaction in parts of the brain responsible for long-term memories and emotions. Brain structure maps also showed the misophonic group had increased myelination, which would suggest healthy brain functioning. The other measures showed the misophonic group had heightened autonomic nervous system responses. The fight-or-flight response was kicked into gear and participants had involuntary physiological reactions similar to those they might have when in physical danger. Still, their emotional reactions were not anxious or fearful, but angry. This study makes it more clear that the nature of misophonia may a combination of neurological and emotional factors.
There are some problems with the research which has been done so far, but in order for more research to be done psychologists will need proper funding from groups which believe the condition is worth studying. One such problem with the research is that the misophonic subjects in these studies are self-identified because there is no way to obtain an official diagnosis. Self-diagnosed test subjects will skew the results and it is hard to say how much of the general population would actually qualify for the diagnosis if it were official. This also relates to the issue of small sample sizes in these studies. The largest sample size was 42 people, which is hardly enough to argue for a new disorder being classified in official diagnostic materials.
Another problem is with the experimental conditions. People with misophonia report that situations are significantly more distressing if they are the type you cannot escape - such as sitting next to a loud chewer on a plane. This cannot be recreated in an experimental setting because one of the ethical requirements of psychological research is that participants have the right to leave at any time. Knowing they can leave will impact the participants’ reactions to stimuli. Additionally, this research uses recordings of commonly-cited trigger sounds which are short audio clips. Similar to knowing you can leave, if you know your trigger sound will end after fifteen seconds then your response to it will be different.
Finally, through interviews the researchers have found that misophonia has a strong social component. Context matters. However, researchers want to avoid purposefully subjecting participants to highly distressing environments because the subjects will remove themselves from the studies. Specific social situations and their influence on symptom presentation are difficult to observe or test.
I gave a presentation on this subject in an abnormal psychology class last year. While describing the symptoms, other students looked at me like it was all completely ridiculous - and these were aspiring therapists! With any luck, researchers will be able to get more funding in the near future for research on misophonia and it will be taken more seriously. Until then, I’ll keep wearing my headphones.