title: Feasibility of an implanted microphone for cochlear implant listening.
abstract: This study aimed at evaluating the feasibility of an implanted microphone for cochlear implants (CI) by comparison of hearing outcomes, sound quality and patient satisfaction of a subcutaneous microphone to a standard external microphone of a behind-the-ear sound processor. In this prospective feasibility study with a within-subject repeated measures design comparing the microphone modalities, ten experienced adult unilateral CI users received an implantable contralateral subcutaneous microphone attached to a percutaneous plug. The signal was pre-processed and fed into their CI sound processor. Subjects compared listening modes at home for a period of up to 4 months. At the end of the study the microphone was explanted. Aided audiometric thresholds, speech understanding in quiet, and sound quality questionnaires were assessed. On average thresholds (250, 500, 750, 1k, 2k, 3k, 4k and 6 kHz) with the subcutaneous microphone were 44.9 dB, compared to 36.4 dB for the external mode. Speech understanding on sentences in quiet was high, within approximately 90% of performance levels compared to hearing with an external microphone. Body sounds were audible but not annoying to almost all subjects. This feasibility study with a research device shows significantly better results than previous studies with implanted microphones. This is attributed to technology enhancements and careful fitting. Listening effort was somewhat increased with an implanted microphone. Under good sound conditions, speech performance is nearly similar to that of external microphones demonstrating that an implanted microphone is feasible in a range of normal listening conditions.
authors.affiliation: ENT Department, UCL Brussels, Brussels, Belgium. jmarcgerard@hotmail.com.|ENT Department, Cleveland Clinic Abu Dhabi, Swing wing 6th floor, Al Maryah Island, PO box 112412, Abu Dhabi, United Arab Emirates. jmarcgerard@hotmail.com.
authors.forename: Jean-Marc
authors.identifier: http://orcid.org/0000-0002-9144-9377
authors.initials: JM
authors.lastname: Gérard
authors.affiliation: ENT Department, CHU Liège, Liege, Belgium.
authors.forename: Laurent
authors.initials: L
authors.lastname: Demanez
authors.affiliation: ENT Department, CHU Liège, Liege, Belgium.
authors.forename: Caroline
authors.initials: C
authors.lastname: Salmon
authors.affiliation: Cochlear Technology Centre, Mechelen, Belgium.
authors.forename: Filiep
authors.initials: F
authors.lastname: Vanpoucke
authors.affiliation: Cochlear Technology Centre, Mechelen, Belgium.
authors.forename: Joris
authors.initials: J
authors.lastname: Walraevens
authors.affiliation: Cochlear Technology Centre, Mechelen, Belgium.
authors.forename: Anke
authors.initials: A
authors.lastname: Plasmans
authors.affiliation: ENT Department, UCL Brussels, Brussels, Belgium.
authors.forename: Daniele
authors.initials: D
authors.lastname: De Siati
authors.affiliation: ENT Department, CHU Liège, Liege, Belgium.
authors.forename: Philippe
authors.initials: P
authors.lastname: Lefèbvre
mesh_terms: D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold; D019929:Cochlear Implantation / Q000379:methods*; D003054:Cochlear Implants; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011446:Prospective Studies; D011474:Prosthesis Design; D013067:Speech Perception
keywords: Cochlear implant; Implantable microphone; Speech performance; Subcutaneous microphone; Totally implantable hearing device