Comparative analysis of the NAL-NL2 and DSL v5.0a prescription procedures in the adaptation of hearing aids in the elderly

Abstract

Purpose: To comparatively analyze the NAL-NL2 and DSL v5.0a prescriptive methods according to the hearing aids individualized programming for the elderly with hearing loss. Methods: The study included 60 elderly individuals with hearing loss, who underwent RECD (Real Ear to Coupler Difference) measurement and hearing aids individualized programming by NAL-NL2 and DSL v5.0a prescriptive methods. The performance verification for each prescription was performed using REAR measurements (Real Ear Aided Response), SII calculation (Speech Intelligibility Index) and HINT (Hearing In Noise Test). The comparative statistical analysis was performed using the paired t-test. Results: The NAL-NL2 method presented a better performance in the REAR evaluation in low and high frequency bands for medium and loud intensity input sounds, in the high frequency range for low intensity input sounds, and in the SII calculation for soft input sounds. The DSL v5.0a presented better results in the REAR evaluation in medium frequencies for medium input sounds, in low and medium frequencies for soft input sounds, in the SII calculation for medium and loud input sound, and in the HINT test in silent and noisy situations. Conclusion: The findings of this study point to an equivalent performance between the DSL v5.0a and NAL-NL2 procedures in the adaptation of hearing aids in the elderly with hearing loss. The amplification calculated by DSL v5.0a provided better speech perception in silence.