Impact of Tinnitus on Quality of Life and Cognitive Function in Adults: A Systematic Review

Background: Tinnitus is often associated with cognitive difficulties, especially in attention and executive functioning. However, it remains unclear how much tinnitus itself contributes to cognitive decline, due to methodological differences among studies and confounding factors like hearing loss and psychological distress. Objective: This systematic review assesses the impact of tinnitus on cognitive function in adults, examining the roles of concomitant hearing loss, mood (including anxiety, depression, and stress), and study design variability. Methods: We conducted a systematic literature search (PUBMED, Google Scholar, Cochrane Library, ScienceDirect) on June 13, 2024, using keywords including “tinnitus,” “cognition,” “attention,” “memory,” and “adults.” Searches were limited to English-language studies. Following PRISMA guidelines, titles and abstracts were screened, and full texts were assessed; 16 studies were included from an initial pool of 24,395 records. Both observational and experimental studies of adults (18–75 years) were reviewed. Inclusion criteria required chronic subjective tinnitus and available data on cognitive outcomes. Exclusion criteria included objective tinnitus, neurodegenerative conditions, the use of ototoxic medications, or a lack of reported cognitive measures. Data were extracted on study design, sample characteristics (age, gender, hearing status), and cognitive outcomes (attention, memory, executive function, processing speed, language), as well as tinnitus assessments. The Mixed Methods Appraisal Tool (MMAT 2018) was used to assess study quality; ten studies were rated as having a low risk of bias, and six were rated as having a moderate risk, with none rated as having a high risk. Results: Across the 16 included studies, tinnitus was most consistently associated with deficits in attentional control and executive processing. The majority of studies (14/16) reported that tinnitus patients performed more poorly than controls on demanding attention tasks (e.g., Stroop test, Trail Making Test). For example, Andersson et al. (2000) found tinnitus patients took significantly longer to name Stroop colors (F(1,44)=17.8, p=0.0001), and Stevens et al. (2007) reported slower reaction times in severe-tinnitus subjects during Stroop trials (t=3.20, p=0.008 for word naming; t=3.10, p=0.011 for color naming). Jackson et al. (2014) also observed reduced accuracy on attention tasks in tinnitus sufferers, with higher tinnitus distress (as measured by the STSS score) correlating with more errors (r = –0.349, p = 0.004). Brueggemann et al. (2021) similarly reported a significant negative correlation between Tinnitus Questionnaire (TQ) scores and Stroop/d2-test performance (β = –0.22, p = 0.001). In contrast, a few studies found little impact on attention: Ciências et al. (2010) noted that mild tinnitus did not impair selective auditory attention or temporal resolution, and Fetoni et al. (2021) found no significant correlation between tinnitus severity (THI) and global cognition (MMSE, r=0.13, p>0.05). Thus, while most evidence indicates attentional inefficiency in tinnitus, effect sizes and significance varied with tinnitus severity and study conditions. Memory and processing speed were also examined. Generally, tinnitus was linked to subtle memory impairments. Pierce et al. (2012) reported that tinnitus patients showed initial deficits in word recall and learning during the first testing session, but their scores normalized on repeated trials (suggesting practice effects). Waechter et al. (2021) found mild working-memory deficits related to tinnitus handicap, even after controlling for hearing loss and mood. Qi et al. (2024) found that tinnitus patients had significantly lower MoCA scores than controls (p < 0.001 for both tinnitus-with-sleep-disorder and tinnitus-without-sleep-disorder groups compared to normal controls), indicating global cognitive differences. In language and executive function, Cardon et al. (2019) observed that tinnitus subjects performed worse on semantic fluency (19.5±6.2 vs. 23.1±5.9; t(54) = 2.21, p = 0.015), suggesting that executive control deficits impacted language (Table 3). Psychological factors frequently mediated cognitive outcomes. Several studies reported that anxiety, depression, and tinnitus distress were associated with poorer cognitive performance, while some cognitive deficits persisted after adjusting for mood. Hearing loss also contributed variably: Fetoni et al. (2021) attributed cognitive impairment mainly to age and hearing loss rather than tinnitus, whereas Gudwani et al. (2017) found no significant correlation between hearing thresholds and cognitive scores. Overall, tinnitus patients often had coexisting high-frequency hearing loss, but its independent effect on cognition was inconsistent. Conclusion: This review suggests that chronic tinnitus is associated with domain-specific cognitive deficits, particularly in attention and executive function, rather than a global decline. Cognitive impairments tend to worsen with greater tinnitus severity and emotional distress. The relationship between tinnitus, hearing loss, and cognition is complex and often confounded, as hearing loss itself (especially untreated) can mimic or exacerbate cognitive effects. Inconsistencies in study design, cognitive tests, and participant matching (including age, hearing, and mood) limit the firmness of conclusions. Future research should employ standardized cognitive batteries, rigorously control for confounding factors (e.g., via well-matched controls or longitudinal designs), and investigate causality. Clinically, a multifaceted approach is recommended: assessment should include cognitive screening, and management should address hearing rehabilitation, psychological support (e.g., CBT for anxiety/depression), and targeted cognitive strategies to improve attention and working memory in tinnitus patients.