title: Improved horizontal directional hearing in bone conduction device users with acquired unilateral conductive hearing loss.
abstract: We examined horizontal directional hearing in patients with acquired severe unilateral conductive hearing loss (UCHL). All patients (n = 12) had been fitted with a bone conduction device (BCD) to restore bilateral hearing. The patients were tested in the unaided (monaural) and aided (binaural) hearing condition. Five listeners without hearing loss were tested as a control group while listening with a monaural plug and earmuff, or with both ears (binaural). We randomly varied stimulus presentation levels to assess whether listeners relied on the acoustic head-shadow effect (HSE) for horizontal (azimuth) localization. Moreover, to prevent sound localization on the basis of monaural spectral shape cues from head and pinna, subjects were exposed to narrow band (1/3 octave) noises. We demonstrate that the BCD significantly improved sound localization in 8/12 of the UCHL patients. Interestingly, under monaural hearing (BCD off), we observed fairly good unaided azimuth localization performance in 4/12 of the patients. Our multiple regression analysis shows that all patients relied on the ambiguous HSE for localization. In contrast, acutely plugged control listeners did not employ the HSE. Our data confirm and further extend results of recent studies on the use of sound localization cues in chronic and acute monaural listening.
authors.affiliation: Department of Biophysics, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Geert Grooteplein 21, 6525 EZ,, P.O. Box 9101,, 6500 HB, Nijmegen, The Netherlands. m.agterberg@donders.ru.nl
authors.forename: Martijn J H
authors.initials: MJ
authors.lastname: Agterberg
authors.forename: Ad F M
authors.initials: AF
authors.lastname: Snik
authors.forename: Myrthe K S
authors.initials: MK
authors.lastname: Hol
authors.forename: Thamar E M
authors.initials: TE
authors.lastname: van Esch
authors.forename: Cor W R J
authors.initials: CW
authors.lastname: Cremers
authors.forename: Marc M
authors.initials: MM
authors.lastname: Van Wanrooij
authors.forename: A John
authors.initials: AJ
authors.lastname: Van Opstal
mesh_terms: D000328:Adult; D001844:Bone Conduction; D019416:Head Movements; D006310:Hearing Aids; D006314:Hearing Loss, Conductive / Q000628:therapy*; D046088:Hearing Loss, Unilateral / Q000628:therapy*; D006320:Hearing Tests; D006801:Humans; D016014:Linear Models; D008875:Middle Aged; D013017:Sound Localization