Test-retest reliability of the profile of hearing aid performance.
This study was designed to replicate the test-retest reliability and critical difference components of the Profile of Hearing Aid Performance (PHAP) as established by Cox and Gilmore (1990). Subjects were 18 experienced hearing aid users ranging in age from 62 to 74 years old. The initial and retest administrations of the PHAP were conducted with no rehabilitative treatment pertaining to hearing loss or amplification provided during the intervening period. The interval between the first and second administrations of the profile was 4-5 months. The mean test-retest difference scores obtained in this investigation were small, not unlike those reported by Cox and Gilmore (1990). Critical difference (CD) values closely approximated those of the previous study except for the Background Noise subscale and the Environment C scale. A pooled estimate of each standard deviation of test-retest differences was computed using data from both investigations. This resulted in critical differences considered to be more precise than the CD values derived from either study alone. Findings strongly support the utility of the PHAP as an effective tool for generating reliable information regarding self-perceived hearing aid performance.