Hyperacusis is an audiological disorder in which patients become persistently overly sensitive and intolerant to everyday environmental sounds that are normally well tolerated by most people [1,2]. Patients suffering from hyperacusis not only can experience pain and discomfort, but also undergo impairments in social, occupational, recreational, and day-to-day activities, resulting in poor quality of life [[1], [2], [3]]. Hyperacusis must be differentiated from recruitment, phonophobia, and misophonia. Phonophobia is a persistent, abnormal fear of sound [2]. Misophonia is an acquired adverse reaction to specific sounds such as chewing or breathing and is associated with emotional responses such as anger [3]. Recruitment is commonly seen in patients with Meniere's disease when there is a sudden increase in sound sensitivity above hearing loss level [1].

The prevalence of hyperacusis ranges from 5.9 % to 17.2 % [4]. There is an association between hyperacusis and tinnitus which has been reported previously. Roughly 40 % of patients with hyperacusis also have tinnitus [5]. Diagnosis of hyperacusis has relied heavily on self-reporting of symptoms and the Tinnitus Retraining Therapy (TRT) interview [6].

Hyperacusis is associated with cochlear damage secondary to loud noise in 62.5 % of cases and other associations include head trauma, depression, anxiety, and adverse medication reactions [7]. However, there is no known cause for many patients. The mechanism of onset is not fully understood, but believed to be due to acoustic overexposure resulting in increased central auditory pathway gain [7]. Pathologies such as superior semicircular canal dehiscence, perilymphatic fistula, and stapes hypermobility have also been proposed as possible etiologies of hyperacusis [4,5,7]. Treatment for hyperacusis includes avoidance of noise stimuli, wearing ear plugs, Tinnitus Retraining Therapy (TRT), cognitive behavioral therapy (CBT), and gradual sound exposure therapy [8,9]. However, there has been insufficient evidence to identify any of these strategies as an effective treatment for hyperacusis [7,8]. Stapes hypermobility has been observed in some hyperacusis patients undergoing reinforcement of the oval and round windows [7,8].