Objectives: The aims of this study were (1) to identify the effect of directional (DIR) processing of commercially available hearing aids via both subjective and objective methods, (2) to determine the association between the results of the subjective and objective evaluations, and (3) to find out individual predictive factors influencing the DIR benefit. Methods:Twenty-six hearing aid users fitted unilaterally with commercially available hearing aids were recruited in this study. All participants' speech perception abilities in noise were tested by using modified Korean hearing in noise test (K-HINT) in three directional conditions; Omni mode, Omni plus noise reduction feature, fixed DIR mode. In order to find out subjective DIR benefit, a structured questionnaire was administrated on speech quality (SQ) and discomfort in noise (DN) domain. Correlation analysis was performed to explore associated factors influencing DIR benefit. Result:Benefit from switching Omni mode to DIR mode in K-HINT were about 2.1 (SD = 2.5) dB SNR, but no significant difference was observed between Omni and Omni plus noise reduction algorithms. Better SQ and DN scores were obtained in DIR mode than in Omni mode. Any individual factors did not significantly associated with both subjective and objective DIR benefits. Conclusion:DIR benefit was observed not only in the objective measurement performed in the laboratory but also in the subjective questionnaires. However, no significant association was found between subjective and objective DIR benefit. Factors influencing individual variation in perceptual DIR benefit were still hard to explain, and further research is needed.