Unilateral Hearing Loss: Prevalence, Causes, Consequences and Available Remedies

Introduction: The prevalence of unilateral sensory neural hearing loss is 3 to 6 in every 1000 people and this prevalence will be about 3 to 5 percent by including conductive hearing loss. Studies have shown that people with unilateral hearing loss are having problems in speech and language development. Nowadays the available options for treatment and rehabilitation of people with unilateral hearing loss, include hearing aids, Contralateral Routing of Signals (CROS), implantable middle ear hearing aid (BAHA) and cochlear implants. Methods: In this review study, unilateral hearing loss was evaluated. Articles from 1990 to 2018, using the key words: Unilateral Hearing Loss, Minimal Hearing Loss were investigated. Finally, 47 articles were selected from the PubMed, Scopus, Google Scholar, Magiran, databases. Results: People with unilateral hearing loss have difficulty in localization and lateralization, speech perception in noise, passing all school grades, proper cognitive functions, age appropriate normal behaviors, depended on hearing loss onset, duration and degree of hearing loss, and affected ear. Moreover, due to hearing deprivation and inappropriate auditory experiences in children with unilateral hearing loss, formation of verbal working memory is not as good as normal hearing peers. Conclusions: In Iran, there is not any documented information about prevalence and risk factors of unilateral hearing loss and problems that these patients may experience. Unilateral hearing loss seems to cause significant hearing impairment.