| differential screening | Process in development of a multicellular organism by which cells become specialised for particular functions. Requires that there is selective expression of portions of the genome, the fully differentiated state may be preceded by a stage in which the cell is already programmed for differentiation but is not yet expressing the characteristic phenotype determination. (18 Nov 1997) |
|---|---|
| drug screening | Preclinical testing of drugs in experimental animals or in vitro for their biological and toxic effects and potential clinical applications. (12 Dec 1998) |
| drug screening assays, antitumour | Methods of investigating the effectiveness of anticancer cytotoxic drugs and biologic inhibitors. These include in vitro cell-kill models and cytostatic dye exclusion tests as well as in vivo measurement of tumour growth parameters in laboratory animals. (12 Dec 1998) |
| familial screening | Screening directed at close relatives of probands with diseases that may lie latent, as in age-dependent dominant traits, or that may involve risk to progeny, as X-linked traits. (05 Mar 2000) |
| american speech-language-hearing association | A professional society concerned with the diagnosis, prevention, treatment, and remediation of speech, language, and hearing disorders. (12 Dec 1998) |
| rehabilitation of hearing impaired | Procedures for assisting a person with a hearing disorder to maximum comprehension in communication. (12 Dec 1998) |
| resonance theory of hearing | That the basilar membrane of the cochlea acts as a resonating structure, recording low tones from its apical turns and high tones from its basal turns. Synonym: Helmholtz theory of hearing. (05 Mar 2000) |
| conductive hearing loss | <otolaryngology> A form of deafness that results from a blockage of the ear canal or dysfunction of the ossicles or eardrum (sound collecting apparatus). In conductive hearing loss the auditory nerve is normal, but there exists a physical problem with the sound collecting apparatus. (05 Jan 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) |