| controlled thermonuclear research | General label for research on controlled thermonuclear fusion reactions. (09 Oct 1997) |
|---|---|
| health outcomes research | The measurement of the value of a particular course of therapy. Health outcomes research is based on the principle that every clinical intervention produces a change in the health status of a patient and that change can be measured. (12 Dec 1998) |
| health services research | The integration of epidemiologic, sociological, economic, and other analytic sciences in the study of health services. Health services research is usually concerned with relationships between need, demand, supply, use, and outcome of health services. The aim of the research is evaluation, particularly in terms of structure, process, output, and outcome. (12 Dec 1998) |
| hearing | The sensation of sound. (12 Dec 1998) |
| hearing aid | An electronic amplifying device designed to bring sound more effectively into the ear; it consists of a microphone, amplifier, and receiver. (05 Mar 2000) |
| hearing aids | Devices which amplify sound to help persons with hearing loss. (12 Dec 1998) |
| hearing impaired persons | Persons with any degree of loss of hearing that has an impact on their activities of daily living or that requires special assistance or intervention. (12 Dec 1998) |
| hearing impairment | Hearing loss A reduction in the ability to perceive sound; may range from slight to complete deafness. See: deafness, threshold shift. (05 Mar 2000) |
| hearing level | The measure of the status of hearing as read directly on the hearing loss scale of an audiometer; described in decibels as a deviation from a standard value for zero on the audiometer. (05 Mar 2000) |
| hearing loss, bilateral | Partial hearing loss in both ears. (12 Dec 1998) |
| hearing loss, central | Hearing loss due to central nervous system disease, anywhere in the auditory pathways from the cochlear nucleus of the pons to the auditory cortex. (12 Dec 1998) |
| hearing loss, conductive | Hearing loss due to interference with the acoustic transmission of sound to the cochlea. The interference is in the outer or middle ear. (12 Dec 1998) |
| hearing loss, functional | Hearing loss without a physical basis. (12 Dec 1998) |
| hearing loss, high-frequency | Hearing loss in frequencies above 1000 hertz. (12 Dec 1998) |
| hearing loss, noise-induced | Hearing loss from exposure to noise. The loss is often in the frequency range 4000-6000 hertz. (12 Dec 1998) |