Hyperacusis is the increased sensitivity to sound and a low tolerance for environmental noise. Definitions of hyperacusis can vary significantly; it can refer to normal noises being perceived as: loud, annoying, painful, fear-inducing, or a combination of those, and is often categorized into four subtypes: loudness, pain, annoyance, and fear.It can be a highly debilitating hearing disorder. Hyperacusis is often coincident with tinnitus. The latter is more common and there are important differences between their involved mechanisms.Little is known about the prevalence of hyperacusis, in part due to the degree of variation in the terms definition. Reported prevalence in children and adolescents ranges from 3% to 17%. Signs and symptoms
In hyperacusis, the symptoms are ear pain, annoyance, distortions, and general intolerance to many sounds that most people are unaffected by. Crying spells or panic attacks may result from the experience of hyperacusis. It may affect only one or both ears. Hyperacusis can also be accompanied by tinnitus. Hyperacusis can result in anxiety, stress and phonophobia. Avoidant behavior is often a response to prevent the effects of hyperacusis and this can include avoiding social situations. Loudness Hyperacusis
Hyperacusis is most often characterized by a sensitivity to sound, where the perception of loudness is much greater than for a typical person; it is often associated with certain volumes and/or frequencies. Hyperacusis can occur in children and adults, and can be either "short-term" in a duration of weeks to less than a year before recovery, or, less-commonly, "long-term", spanning years and in some cases becoming permanent.
Treatment
Avoidance and Hearing Protection
Setback prevention and reduction of pain symptoms are high priorities among those with hyperacusis and noxacusis, which is often managed through a combination of controlling the environment so as to avoid loud sounds, soundproofing, and wearing hearing protection, such as earplugs and/or safety earmuffs, such as the type used at firing ranges or industrial applications

Diet
Diet may play a role in symptom management in some cases of hyperacusis, with response to a migraine diet, low-histamine diet, or low sodium diet. Sound Therapy
Sound therapy is sometimes recommended for those with hyperacusis, though its application among those with pain (noxacusis) should be used with caution. Tinnitus retraining therapy, a treatment originally used to treat tinnitus, uses broadband noise to treat hyperacusis. Pink noise can also be used to treat hyperacusis. By listening to broadband noise at soft levels for a disciplined period of time each day, some patients can rebuild (i.e., re-establish) their tolerances to sound. More research is needed on the efficacy of sound therapy techniques when hyperacusis is the primary complaint, rather than a secondary symptom, indicating that "no strong conclusions can be made" about its efficacy at this time. Cognitive Behavioral Therapy
Another possible treatment is cognitive behavioral therapy (CBT), which may also be combined with sound therapy. However, randomized controlled trials with active control groups are still needed to establish the effectiveness of CBT for hyperacusis and the usefulness of CBT for noxacusis (pain hyperacusis) is not yet demonstrated in the scientific literature.