title: A clinical comparative investigation of a non-linear versus linear hearing aid.
abstract: The objective of this study was to compare the effect and performance of a hearing aid (HA) having a non-linear amplification below 1600 Hz (test HA) with a linear amplifying HA (control HA), aiming towards identical target groups of hearing-disabled people. The investigation was designed as a single-blind crossover interview study, i.e. the interviewer was blind. Thirty-two experienced HA users at a median age of 74 years participated. The observation period was 6-8 weeks for both HAs. For several evaluation parameters the participants found the test HA superior to the control HA, and a significantly better effect of the test HA was indicated in person-to-person conversation in quiet surroundings. Also, quality of sound was significantly better in the test HA, and thus these parameters support the test HA, being preferred by 75%. No significant differences were found in the objectively evaluated parameter, i.e. speech recognition score in background noise (SRSN: S/N = 0) between the two aids. A one-year follow-up examination of those preferring the test HA demonstrated continuously frequent use and satisfaction with the automatic volume control. It is concluded that skilled HA users with a wide range of hearing impairment at an age of 60-80 years prefer a non-linear HA to their current linear HA when fitted monaurally--however, a certain bias in the unblinded test subjects cannot be excluded.
authors.affiliation: Department of Audiology, Bispebjerg Hospital, Copenhagen, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Biering-Sørensen
authors.forename: H
authors.initials: H
authors.lastname: Riess
authors.forename: G
authors.initials: G
authors.lastname: Boisen
authors.forename: A
authors.initials: A
authors.lastname: Parving
mesh_terms: D000368:Aged; D018592:Cross-Over Studies; D005260:Female; D006310:Hearing Aids; D006314:Hearing Loss, Conductive / Q000534:rehabilitation*; D006319:Hearing Loss, Sensorineural / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016037:Single-Blind Method; D011795:Surveys and Questionnaires; D013997:Time Factors