title: Clinical evaluation of cochlear implant sound coding taking into account conjectural masking functions, MP3000™.
abstract: Efficacy of the SPEAK and ACE coding strategies was compared with that of a new strategy, MP3000™, by 37 European implant centers including 221 subjects. The SPEAK and ACE strategies are based on selection of 8-10 spectral components with the highest levels, while MP3000  is based on the selection of only 4-6 components, with the highest levels relative to an estimate of the spread of masking. The pulse rate per component was fixed. No significant difference was found for the speech scores and for coding preference between the SPEAK/ACE and MP3000 strategies.  Battery life was 24% longer for the MP3000 strategy. With MP3000 the best results were found for a selection of six components. In addition, the best results were found for a masking function with a low-frequency slope of 50 dB/Bark and a high-frequency slope of 37 dB/Bark (50/37)  as compared to the other combinations examined of 40/30 and 20/15 dB/Bark. The best results found for the steepest slopes do not seem to agree with current estimates of the spread of masking in electrical stimulation. Future research might reveal if performance with respect to SPEAK/ACE  can be enhanced by increasing the number of channels in MP3000 beyond 4-6 and it should shed more light on the optimum steepness of the slopes of the masking functions applied in MP3000.
authors.affiliation: Medizinische Hochschule Hannover (MHH), Hannover, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Buechner
authors.forename: Andy
authors.initials: A
authors.lastname: Beynon
authors.forename: Witold
authors.initials: W
authors.lastname: Szyfter
authors.forename: Kazimierz
authors.initials: K
authors.lastname: Niemczyk
authors.forename: Ulrich
authors.initials: U
authors.lastname: Hoppe
authors.forename: Matthias
authors.initials: M
authors.lastname: Hey
authors.forename: Jan
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authors.lastname: Brokx
authors.forename: Julie
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authors.lastname: Eyles
authors.forename: Paul
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authors.lastname: Van de Heyning
authors.forename: Gaetano
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authors.lastname: Paludetti
authors.forename: Andrzej
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authors.lastname: Zarowski
authors.forename: Nicola
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authors.lastname: Quaranta
authors.forename: Thomas
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authors.lastname: Wesarg
authors.forename: Joost
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authors.lastname: Festen
authors.forename: Heidi
authors.initials: H
authors.lastname: Olze
authors.forename: Ingeborg
authors.initials: I
authors.lastname: Dhooge
authors.forename: Joachim
authors.initials: J
authors.lastname: Müller-Deile
authors.forename: Angel
authors.initials: A
authors.lastname: Ramos
authors.forename: Stephane
authors.initials: S
authors.lastname: Roman
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Piron
authors.forename: Domenico
authors.initials: D
authors.lastname: Cuda
authors.forename: Sandro
authors.initials: S
authors.lastname: Burdo
authors.forename: Wilko
authors.initials: W
authors.lastname: Grolman
authors.forename: Samantha Roux
authors.initials: SR
authors.lastname: Vaillard
authors.forename: Alicia
authors.initials: A
authors.lastname: Huarte
authors.forename: Bruno
authors.initials: B
authors.lastname: Frachet
authors.forename: Constantine
authors.initials: C
authors.lastname: Morera
authors.forename: Luis
authors.initials: L
authors.lastname: Garcia-Ibáñez
authors.forename: Daniel
authors.initials: D
authors.lastname: Abels
authors.forename: Martin
authors.initials: M
authors.lastname: Walger
authors.forename: Jochen
authors.initials: J
authors.lastname: Müller-Mazotta
authors.forename: Carlo Antonio
authors.initials: CA
authors.lastname: Leone
authors.forename: Bernard
authors.initials: B
authors.lastname: Meyer
authors.forename: Norbert
authors.initials: N
authors.lastname: Dillier
authors.forename: Thomas
authors.initials: T
authors.lastname: Steffens
authors.forename: André
authors.initials: A
authors.lastname: Gentine
authors.forename: Manuela
authors.initials: M
authors.lastname: Mazzoli
authors.forename: Gerben
authors.initials: G
authors.lastname: Rypkema
authors.forename: Matthijs
authors.initials: M
authors.lastname: Killian
authors.forename: Guido
authors.initials: G
authors.lastname: Smoorenburg
mesh_terms: D000161:Acoustic Stimulation / Q000295:instrumentation; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D019929:Cochlear Implantation / Q000295:instrumentation; D003054:Cochlear Implants; D004581:Electronics; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010470:Perceptual Masking; D011601:Psychophysics; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation; D013057:Spectrum Analysis; D013061:Speech Acoustics; D013686:Telemetry / Q000379:methods; D055815:Young Adult