Tinnitus is the perception of sound in the absence of a corresponding external sound source, and bothersome tinnitus has been linked to poorer cognitive performance. This review comprehensively quantifies the association between tinnitus and different domains of cognitive performance. The review protocol was preregistered and published in a peer-reviewed journal. The review and analyses were reported according to Preferred Reporting Items for Systematic Review and Meta-analysis guidelines. Peer-reviewed literature was searched using electronic databases to find studies featuring participants with tinnitus who had undertaken measures of cognitive performance. Studies were assessed for quality and categorized according to an established cognitive framework. Random-effects meta-analyses were performed on various cognitive domains with potential moderator variables assessed where possible. Thirty-eight records were included in the analysis from a total of 1,863 participants. Analyses showed that tinnitus is associated with poorer executive function, processing speed, general short-term memory, and general learning and retrieval. Narrow cognitive domains of Inhibition and Shifting (within executive function) and learning and retrieval (within general learning and retrieval) were also associated with tinnitus.

IntroductionSubjective tinnitus is very common and has a number of comorbid associations including depression, sleep disturbance and concentration difficulties. Concentration difficulties may be observable in people with tinnitus through poorer behavioural performance in tasks thought to measure specific cognitive domains such as attention and memory (ie, cognitive performance). Several reviews have discussed the association between tinnitus and cognition; however, none to date have investigated the association between tinnitus and cognitive performance through meta-analysis with reference to an established theoretical taxonomy. Furthermore, there has been little overlap between sets of studies that have been included in previous reviews, potentially contributing to the typically mixed findings that are reported.Methods and analysisThis systematic review aims to comprehensively review the literature using an established theoretical taxonomy and quantitatively synthesise relevant data to determine associations between subjective tinnitus and cognitive performance. Methods are reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols. All study designs will be eligible for inclusion with no date restrictions on searches. Studies eligible for inclusion must contain adult participants (≥18 years) with subjective tinnitus and a behavioural measure of cognitive performance. Meta-analysis will be reported via correlation for the association between tinnitus and cognitive performance.Ethics and disseminationNo ethical issues are foreseen. Findings will be reported in a student thesis, at national and international, ear, nose and throat/audiology conferences and by peer-reviewed publication.PROSPERO registration numberCRD42018085528.