Publications (2)2.87 Total impact
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Article: Speech recognition in cochlear implant recipients: comparison of standard HiRes and HiRes 120 sound processing.
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ABSTRACT: HiRes (HR) 120 is a sound-processing strategy purported to offer an increase in the precision of frequency-to-place mapping through the use of current steering. This within-subject study was designed to compare speech recognition as well as music and sound quality ratings for HR and HR 120 processing. Cochlear implant/tertiary referral center. Eight postlinguistically deafened adults implanted with an Advanced Bionics CII or HR 90K cochlear implant. STUDY DESIGN/MAIN OUTCOME MEASURES: Performance with HR and HR 120 was assessed during 4 test sessions with a battery of measures including monosyllabic words, sentences in quiet and in noise, and ratings of sound quality and musical passages. Compared with HR, speech recognition results in adult cochlear implant recipients revealed small but significant improvements with HR 120 for single syllable words and for 2 of 3 sentence recognition measures in noise. Both easy and more difficult sentence material presented in quiet were not significantly different between strategies. Additionally, music quality ratings were significantly better for HR 120 than for HR, and 7 of 8 subjects preferred HR 120 over HR for listening in everyday life. HR 120 may offer equivalent or improved benefit to patients compared with HR. Differences in performance on test measures between strategies are dependent on speech recognition materials and listening conditions.Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 01/2009; 30(2):146-52. · 1.44 Impact Factor -
Article: Role of electrode placement as a contributor to variability in cochlear implant outcomes.
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ABSTRACT: Suboptimal cochlear implant (CI) electrode array placement may reduce presentation of coded information to the central nervous system and, consequently, limit speech recognition. Generally, mean speech reception scores for CI recipients are similar across different CI systems, yet large outcome variation is observed among recipients implanted with the same device. These observations suggest significant recipient-dependent factors influence speech reception performance. This study examines electrode array insertion depth and scalar placement as recipient-dependent factors affecting outcome. Scalar location and depth of insertion of intracochlear electrodes were measured in 14 patients implanted with Advanced Bionics electrode arrays and whose word recognition scores varied broadly. Electrode position was measured using computed tomographic images of the cochlea and correlated with stable monosyllabic word recognition scores. Electrode placement, primarily in terms of depth of insertion and scala tympani versus scala vestibuli location, varies widely across subjects. Lower outcome scores are associated with greater insertion depth and greater number of contacts being located in scala vestibuli. Three patterns of scalar placement are observed suggesting variability in insertion dynamics arising from surgical technique. A significant portion of variability in word recognition scores across a broad range of performance levels of CI subjects is explained by variability in scalar location and insertion depth of the electrode array. We suggest that this variability in electrode placement can be reduced and average speech reception improved by better selection of cochleostomy sites, revised insertion approaches, and control of insertion depth during surgical placement of the array.Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 08/2008; 29(7):920-8. · 1.44 Impact Factor
