title: Frequency-dependent loudness balancing in bimodal cochlear implant users.
abstract: Conclusion In users of a cochlear implant (CI) and a hearing aid (HA) in contralateral ears, frequency-dependent loudness balancing between devices did, on average, not lead to improved speech understanding as compared to broadband balancing. However, nine out of 15 bimodal subjects showed significantly better speech understanding with either one of the fittings. Objectives Sub-optimal fittings and mismatches in loudness are possible explanations for the large individual differences seen in listeners using bimodal stimulation. Methods HA gain was adjusted for soft and loud input sounds in three frequency bands (0-548, 548-1000, and >1000 Hz) to match loudness with the CI. This procedure was compared to a simple broadband balancing procedure that reflected current clinical practice. In a three-visit cross-over design with 4 weeks between sessions, speech understanding was tested in quiet and in noise and questionnaires were administered to assess benefit in real world. Results Both procedures resulted in comparable HA gains. For speech in noise, a marginal bimodal benefit of 0.3 ± 4 dB was found, with large differences between subjects and spatial configurations. Speech understanding in quiet and in noise did not differ between the two loudness balancing procedures.
authors.affiliation: a Department of Biophysics, Donders Institute for Brain, Cognition and Behaviour , Radboud University Nijmegen , Nijmegen , the Netherlands ;
authors.forename: Lidwien C E
authors.initials: LC
authors.lastname: Veugen
authors.affiliation: b Advanced Bionics European Research Centre (AB ERC) , Hannover , Germany ;
authors.forename: Josef
authors.initials: J
authors.lastname: Chalupper
authors.affiliation: c Department of Otorhinolaryngology , Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre , the Netherlands.
authors.forename: Ad F M
authors.initials: AF
authors.lastname: Snik
authors.affiliation: a Department of Biophysics, Donders Institute for Brain, Cognition and Behaviour , Radboud University Nijmegen , Nijmegen , the Netherlands ;
authors.forename: A John
authors.initials: AJ
authors.lastname: van Opstal
authors.affiliation: c Department of Otorhinolaryngology , Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen Medical Centre , the Netherlands.
authors.forename: Lucas H M
authors.initials: LH
authors.lastname: Mens
mesh_terms: D000368:Aged; D003054:Cochlear Implants; D005260:Female; D006801:Humans; D008144:Loudness Perception; D008297:Male; D008875:Middle Aged; D009622:Noise; D013067:Speech Perception
keywords: Bimodal stimulation; cochlear implants; hearing aids; loudness balancing; speech perception