title: Factors constraining the benefit to speech understanding of combining information from low-frequency hearing and a cochlear implant.
abstract: Many studies have documented the benefits to speech understanding when cochlear implant (CI) patients can access low-frequency acoustic information from the ear opposite the implant. In this study we assessed the role of three factors in determining the magnitude of bimodal benefit - (i) the level of CI-only performance, (ii) the magnitude of the hearing loss in the ear with low-frequency acoustic hearing and (iii) the type of test material. The patients had low-frequency PTAs (average of 125, 250 and 500 Hz) varying over a large range (<30 dB HL to >70 dB HL) in the ear contralateral to the implant. The patients were tested with (i) CNC words presented in quiet (n = 105) (ii) AzBio sentences presented in quiet (n = 102), (iii) AzBio sentences in noise at +10 dB signal-to-noise ratio (SNR) (n = 69), and (iv) AzBio sentences at +5 dB SNR (n = 64). We find maximum bimodal benefit when (i) CI scores are less than 60 percent correct, (ii) hearing loss is less than 60 dB HL in low-frequencies and (iii) the test material is sentences presented against a noise background. When these criteria are met, some bimodal patients can gain 40-60 percentage points in performance relative to performance with a CI. This article is part of a Special Issue entitled <Lasker Award>.
authors.affiliation: Arizona State University, Department of Speech and Hearing Science, Tempe, AZ 85287, USA. Electronic address: mdorman@asu.edu.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Dorman
authors.affiliation: Arizona State University, Department of Speech and Hearing Science, Tempe, AZ 85287, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Cook
authors.affiliation: Advanced Bionics 28515 Westinghouse Pl, Valencia, CA 91355, USA.
authors.forename: Anthony
authors.initials: A
authors.lastname: Spahr
authors.affiliation: Arizona State University, Department of Speech and Hearing Science, Tempe, AZ 85287, USA.
authors.forename: Ting
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Arizona State University, Department of Speech and Hearing Science, Tempe, AZ 85287, USA.
authors.forename: Louise
authors.initials: L
authors.lastname: Loiselle
authors.affiliation: University of Ottawa Faculty of Medicine, 451 Smyth Rd. Ottawa, Ontario, Canada K1H 8M5.
authors.forename: David
authors.initials: D
authors.lastname: Schramm
authors.affiliation: University of Ottawa Faculty of Medicine, 451 Smyth Rd. Ottawa, Ontario, Canada K1H 8M5.
authors.forename: JoAnne
authors.initials: J
authors.lastname: Whittingham
authors.affiliation: Vanderbilt University, Department of Hearing and Speech Sciences, Nashville, TN 37232, USA.
authors.forename: Rene
authors.initials: R
authors.lastname: Gifford
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001302:Audiometry, Speech; D001309:Auditory Threshold; D019929:Cochlear Implantation / Q000295:instrumentation*; D003054:Cochlear Implants; D032882:Comprehension; D004558:Electric Stimulation; D034381:Hearing Loss / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology / Q000534:rehabilitation*; D006801:Humans; D008875:Middle Aged; D009622:Noise / Q000009:adverse effects; D010470:Perceptual Masking; D019986:Persons with Hearing Disabilities / Q000523:psychology / Q000534:rehabilitation*; D011474:Prosthesis Design; D012720:Severity of Illness Index; D012815:Signal Processing, Computer-Assisted; D013065:Speech Intelligibility; D013067:Speech Perception; D055815:Young Adult