Relationship between hyperacusis and auditory processing disorder: a literature review

Abstract

Hyperacusis has been defined as the excessive auditory sensitivity or intolerance to certain everyday sounds that seem common for most people. Considering the underlying physiolo- gical mechanisms of hyperacusis, it is reasonable to think that it could affect some abilities involved in the central auditory processing. However, there is lack of evidence about this topic, and there is no literature review that gathers all the existing research. Therefore, the current study intends to identify and analyze the available scientific evidence regarding the relationship between hyperacusis and central auditory processing disorder. The review of the literature followed the PRISMA protocol, using key words in Proquest, Ebsco, Pubmed, ScienceDirect, Cochrane Library and Scielo databases. Original research articles, systema- tic reviews and meta-analyses of studies made with human and animals that have been published since 2010 in English, Spanish and Portuguese were included. Among them, 323 studies were related to the key terms, out of which 13 met the inclusion criteria and were analyzed. It is possible to conclude that there is little and incipient scientific evidence on the topic. Structures of the central auditory pathway such as cochlear nuclei, lateral lemniscus, inferior colliculi, medial geniculate body and primary auditory cortex seem to be related to hyperacusis; auditory processing skills such as figure/ground discrimination, temporal ordering and interhemispheric transfer appear to be affected as well.