title: Evaluation and assessment of FM systems.
abstract: In the past, frequency modulated (FM) systems were recommended for use only in educational settings for children with severe or profound hearing losses. Recent studies, however, have suggested that FM systems may be appropriate in nonacademic settings and also may benefit children with minimal hearing loss. In addition to the more widespread application of FM use, advances in amplification technology have provided audiologists with a variety of devices and coupling options, resulting in more variables to evaluate in the fitting process. There are three commonly used methods of evaluating FM systems: functional gain measures, probe tube microphone measures, and coupler measures. This paper is intended to provide the audiologist working with FM systems with an overview of the complexities involved in selecting and setting FM systems and the benefits and limitations of each evaluation method. Each evaluation method is examined in view of how well it answers three basic questions related to frequency response, maximum output, and distortion in FM systems. Finally, other issues which may impact on the selection of an FM system for a given individual are discussed.
authors.affiliation: Boys Town National Institute, Omaha, Nebraska.
authors.forename: D E
authors.initials: DE
authors.lastname: Lewis
authors.forename: J A
authors.initials: JA
authors.lastname: Feigin
authors.forename: A E
authors.initials: AE
authors.lastname: Karasek
authors.forename: P G
authors.initials: PG
authors.lastname: Stelmachowicz
mesh_terms: D000162:Acoustics; D000328:Adult; D000669:Amplifiers, Electronic; D001298:Audiology / Q000295:instrumentation*; D002648:Child; D002675:Child, Preschool; D012048:Correction of Hearing Impairment; D005069:Evaluation Studies as Topic; D006801:Humans; D008144:Loudness Perception; D008297:Male; D011846:Radio Waves; D013063:Speech Discrimination Tests; D013065:Speech Intelligibility