Coupler and real-ear measurement of hearing aid gain and output in the NIDCD/VA Hearing Aid Clinical Trial.

Objective: Because the NIDCD/VA Hearing Aid Clinical Trial was conducted across eight clinical sites, rigorous control of the electroacoustic characteristics of the experimental devices was required.

Design: The parameters monitored included the gain and output of the approximately 720 hearing aids in the trial, measured both in the 2 cm3 coupler and in situ. Each measurement was repeated six times on each hearing aid across the 9-mo duration of the study to insure both the stability and the accuracy of the circuits under investigation.

Subjective measures of hearing aid benefit in the NIDCD/VA Clinical Trial.

Objective: Subjective measures of performance were assessed on three different hearing aid circuits as part of a large clinical trial. These measurements included the Profile of Hearing Aid Performance and a subjective ranking of individual preference.

Design: A multi-center, double-masked clinical trial of hearing aids was conducted at eight VA Medical Centers.

Quality rating test of hearing aid benefit in the NIDCD/VA Clinical Trial.

Objective: As part of a large clinical trial that compared three hearing aid circuits using several evaluation methods, judgments about quality of listening experiences were sought from all subjects. Three dimensions were examined: loudness, noise interference and overall liking (quality).

Design: Eight Audiology units in VA Medical Centers participated.

Organization and administration of the NIDCD/VA Hearing Aid Clinical Trial.

This article describes the organization and administration of the NIDCD/VA Hearing Aid Clinical Trial. The trial involved a total of 360 patients with bilateral, sensorineural hearing loss from eight VA Medical Centers to study three different hearing aid circuits in a three-period, three-treatment crossover design. Strong central coordination of such a complex multi-center clinical trial is essential to its success.

A multi-center, double blind clinical trial comparing benefit from three commonly used hearing aid circuits.

Objective: Although numerous studies have demonstrated that hearing aids provide significant benefit, carefully controlled, multi-center clinical trials have not been conducted. A multi-center clinical trial was conducted to compare the efficacy of three commonly used hearing aid circuits: peak clipping, compression limiting, and wide dynamic range compression.

Design: Patients (N = 360) with bilateral, sensorineural hearing loss were studied using a double blind, three-period, three-treatment crossover design.