Randomized trial of amplification strategies

Background: Little is known about quality of life after the use of specific types of hearing aids, so it is difficult to determine whether technologie s such as programmable circuits and directional microphones are worth the a dded expense. Objective: To compare the effectiveness of an assistive listening device, a nonprogrammable nondirectional microphone hearing aid, with that of a prog rammable directional microphone hearing aid against the absence of amplific ation. Design: Randomized controlled trial. Setting: Audiology clinic at the VA Puget Sound Health Care System, Seattle , Wash. Patients: Sixty veterans with bilateral moderate to severe sensorineural he aring loss completed the trial. Half the veterans (n = 30) had hearing loss that the Veterans Affairs clinic determined was rated as "service connecte d," which meant that they were eligible for Veterans Affairs-issued hearing aids. Intervention: Veterans with non-service-connected hearing loss, who were in eligible for Veterans Affairs-issued hearing aids, were randomly assigned t o no amplification (control arm) or to receive an assistive listening devic e. Veterans with service-connected loss were randomly assigned to receive e ither the nonprogrammable hearing aid that is routinely issued ("convention al") or a programmable aid with a directional microphone ("programmable"). Main Outcome Measures: Hearing-related quality of life, self-rated communic ation ability, adherence to use, and willingness to pay for the amplificati on devices (measured 3 months after fitting). Results: Clear distinctions were observed between all 4 arms. The mean impr ovement in hearing-related quality of life (Hearing Handicap Inventory for the Elderly) scores was small for control patients (2.2 points) and patient s who received an assistive listening device (4.4 points), excellent for pa tients who received a conventional device (17.4 points), and substantial fo r patients who received a programmable device (31.1 points) (P<.001 by the analysis of variance test). Qualitative analyses of free-text diary entries , self-reported communication ability (Abbreviated Profile of Hearing Aid B enefit) scores, adherence to hearing aid use, and willingness to pay for re placement devices showed similar trends. Conclusions: A programmable hearing aid with a directional microphone had t he highest level of effectiveness in the veteran population. A nonprogramma ble hearing aid with an omnidirectional microphone was also effective compa red with an assistive listening device or no amplification.