The Impact of Hearing Aid Use on Sound Localization and Speech Recognition in Noise: A Longitudinal Study

Background and Objectives This study investigates the impact of hearing aid usage on sound localization and speech recognition in noise over time among elderly individuals with hearing impairments.Subjects and Method Thirteen older adults with sensorineural hearing loss (mean age: 73.69±6.75 years; M:F=7:6) participated. Sound localization was assessed using seven speakers arranged at 30° intervals, each delivering three presentations. Speech recognition in noise was measured using an adaptive method to determine the signal-to-noise ratio for 50% correct recognition of Korean Matrix sentences. All stimuli were presented at 65 dBA from the speaker 1 m in front. Assessments were conducted at four time points: pre-fitting, 1, 3, and 6 months post-fitting.Results The sound localization test indicated changes over time in percent correct total (<i>p</i>=0.024), mean absolute error (<i>p</i>=0.017), and root mean square error (<i>p</i>=0.022). Post hoc pairwise comparisons revealed a significant improvement in percent correct localization between the pre-fitting and 6-month conditions (<i>p</i>=0.047). Speech recognition in noise improved after hearing aid use at nearly all time points in the speech-shaped noise and the International Speech Test Signal conditions (all <i>p</i><0.05), but the degree of improvement did not increase significantly with prolonged usage.Conclusion The overall trend suggests that sound localization shows potential for gradual improvement with long-term hearing aid use, whereas speech recognition improves in the early stages of hearing aid use but remains unchanged over time.