Table 1.

Comparison of the Hyperacusis, Misophonia, and Phonophobia

	Hyperacusis	Misophonia	Phonophobia
Definition	A hearing disorder in which sound of moderate intensity is perceived as excessively loud, painful, and/or overwhelming.	A neuropsychiatric condition in which individuals have excessive and inappropriate emotional responses to specific “trigger” sounds (e.g., chewing, tapping, sniffling), even when presented at a low level.	A specific phobia of particular sounds or classes of sounds, resulting in anticipatory responses and avoidance of potential sound sources.
Limited to specific sounds	No	Yes	Yes
Primary response to sound	Excessive loudness sensation and/or pain in ears/head	Anger, disgust, and/or extreme irritation	Fear and/or panic, anticipatory anxiety
Psychoacoustic loudness perception	Steeper loudness growth, reduced LDL	Normal	Unknown (possibly reduced LDL)
Influence of contextual factors	Low	High	High
Results in avoidance behavior	Yes	Yes	Yes
Associated with psychopathology	Yes	Yes	Yes
Occurs secondarily to	Cochlear hearing loss, noise trauma, brain injury	Unknown	Hyperacusis, reactive tinnitus, misophonia, posttraumatic stress disorder, other anxiety disorders
Proposed cognitive mechanism	Amplification of low-level sensory information resulting in a steeper growth of subjective loudness with increasing sound level.	Attribution of excess salience to particular sounds or associated perceptual phenomena (e.g., sights), resulting in conditioned aversive emotional response and heightened sympathetic arousal.	Pathological fear learning, combining excess attribution of threat to specific sounds with poor experience-dependent extinction. Maintained by avoidance of feared stimulus.
Implicated brain regions	Primary/secondary auditory cortex, inferior colliculus, auditory brainstem (superior olivary complex)	Salience network (anterior insular cortex, dorsal anterior cingulate cortex), ventromedial prefrontal cortex, posteromedial cortex, hippocampus, amygdala	Amygdala, hippocampus, anterior cingulate cortex, ventromedial prefrontal cortex, anterior insular cortex, bed nucleus of the stria terminalis/extended amygdala
Increased prevalence in autism	Yes	Unknown	Yes
Unique pathophysiology in autism	Yes	No	No

Note. LDL = loudness discomfort level (the decibel level at which a sound starts being perceived as uncomfortably loud).