Background <p>Hearing aids are used to mitigate the adverse effects of hearing loss.</p> Aims <p>To investigate the relationship between hearing ability, cognitive skills, and verbal fluency before and after hearing aid use in individuals with presbycusis, and to understand the effect of unilateral or bilateral hearing aid use on these possible changes.</p> Methods <p>A total of 39 patients with presbycusis were included in the study. Patients who benefited from unilateral or bilateral hearing aids were assigned to Groups 1 and 2, respectively. All patients underwent one cognitive test (standardized mini-mental state examination [SMMSE]) and two separate verbal fluency tests (phonemic fluency test [PFT] and semantic fluency test [SFT]), both before and after at least 6&#xa0;months of hearing aid use. SMMSE, PFT, and SFT scores before and after device use and the intergroup percentage change in these scores were compared.</p> Results <p>Groups 1 and 2 showed significantly higher SMMSE and PFT scores after hearing aid use compared to those before (p &lt; 0.05). No intergroup differences were found when comparing the percentage change in SMMSE and PFT scores (p &gt; 0.05). There was a significant improvement in cognitive and verbal fluency tests after hearing aid use compared to before. However, the use of unilateral or bilateral devices did not influence this improvement.</p> Conclusions <p>This study is the first prospective study in the literature to investigate the effect of unilateral and bilateral hearing aid use on cognitive and verbal fluency tests in patients with presbycusis.</p>