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 technologies such as programmable circuits and directional microphones are worth the added expense. OBJECTIVE: To compare the effectiveness of an assistive listening device, a nonprogrammable nondirectional microphone hearing aid, with that of a programmable directional microphone hearing aid against the absence of amplification. 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 hearing loss completed the trial. Half the veterans (n = 30) had hearing loss that the Veterans Affairs clinic determined was rated as "service connected," which meant that they were eligible for Veterans Affairs-issued hearing aids. INTERVENTION: Veterans with non-service-connected hearing loss, who were ineligible for Veterans Affairs-issued hearing aids, were randomly assigned to no amplification (control arm) or to receive an assistive listening device. Veterans with service-connected loss were randomly assigned to receive either the nonprogrammable hearing aid that is routinely issued ("conventional") or a programmable aid with a directional microphone ("programmable"). MAIN OUTCOME MEASURES: Hearing-related quality of life, self-rated communication ability, adherence to use, and willingness to pay for the amplification devices (measured 3 months after fitting). RESULTS: Clear distinctions were observed between all 4 arms. The mean improvement in hearing-related quality of life (Hearing Handicap Inventory for the Elderly) scores was small for control patients (2.2 points) and patients who received an assistive listening device (4.4 points), excellent for patients who received a conventional device (17.4 points), and substantial for 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 Benefit) scores, adherence to hearing aid use, and willingness to pay for replacement devices showed similar trends. CONCLUSIONS: A programmable hearing aid with a directional microphone had the highest level of effectiveness in the veteran population. A nonprogrammable hearing aid with an omnidirectional microphone was also effective compared with an assistive listening device or no amplification.

Fitting hearing aids with the Articulation Index: impact on hearing aid effectiveness.

Although most clinical tests focus on how much a particular hearing aid improves speech audibility under controlled conditions, it is unclear how these measures relate to hearing aid effectiveness, or the benefit perceived by the patient under everyday conditions. In this study, the relationship between audibility and hearing aid effectiveness was examined in a cohort of patients who obtained hearing aids through the Veteran's Administration. The measure of audibility was the Articulation Index, a common index of speech audibility. Measures of effectiveness included two hearing-specific surveys and self-reported ratings of global satisfaction and hearing aid use adherence. Results indicated that there were no systematic relationships between measurements of improved audibility and patient ratings of communication ability. Additionally, improved audibility was not related to overall satisfaction with the amplification characteristics of the hearing aid (fitting). However, improved audibility is related to hearing aid use adherence, with patients who achieve better audibility reporting that they use their hearing aids more frequently.

The role of assistive devices in the rehabilitation of hearing impairment.

Formal investigation and clinical experience have revealed success in the use of assistive devices in aiding speech understanding where conventional amplification alone has failed. The long-term benefits of this technology are keeping people, particularly the elderly, socially engaged and independent. To accomplish this end, hearing health care professionals have not only to arm themselves with a rapidly advancing, complex array of technical tools, but also to apply them efficaciously. This article provides an overview of these tools, the procedures for using them, the criteria for selecting them, and the resources for obtaining them. A discussion of the various types of assistive devices and their application is followed by a review of the principles for selection and fitting and concludes with a review of the modern role of the hearing health care provider.