Browsing by Author "Harris, Michael S."

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    An analysis of hearing aid fittings in adults using cochlear implants and contralateral hearing aids
    (Wiley, 2010-12) Harris, Michael S.; Hay-McCutcheon, Marcia; Otolaryngology -- Head and Neck Surgery, School of Medicine
    OBJECTIVES/HYPOTHESIS: The objective of this study was to assess the appropriateness of hearing aid fittings within a sample of adult cochlear implant recipients who use a hearing aid in the contralateral ear (i.e., bimodal stimulation). METHODS: The hearing aid gain was measured using real ear testing for 14 postlingually deaf English-speaking adults who use a cochlear implant in the contralateral ear. Unaided and aided audiometric testing assessed the degree of functional gain derived from hearing aid use. RESULTS: On average, the target to actual output level difference was within 10 dB only at frequencies of 750 Hz and 1,000 Hz. Only 1 of the 14 study participants had a hearing aid for which the majority of the tested frequencies were within 10 dB of the target gain. In addition, a greater amount of functional gain (i.e., the increase in unaided behavioral thresholds after amplification) was provided for lower frequencies than higher frequencies. CONCLUSIONS: Hearing aid settings in our sample were suboptimal and may be regarded as a contributing factor to the variability in bimodal benefit. Refining hearing aid fitting strategies tailored to the needs of the concurrent cochlear implant and hearing aid user is recommended.
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    Contribution of Verbal Learning & Memory and Spectro-Temporal Discrimination to Speech Recognition in Cochlear Implant Users
    (Wiley, 2023) Harris, Michael S.; Hamel, Benjamin L.; Wichert, Kristin; Kozlowski, Kristin; Mleziva, Sarah; Ray, Christin; Pisoni, David B.; Kronenberger, William G.; Moberly, Aaron C.; Psychiatry, School of Medicine
    Objectives: Existing cochlear implant (CI) outcomes research demonstrates a high degree of variability in device effectiveness among experienced CI users. Increasing evidence suggests that verbal learning and memory (VL&M) may have an influence on speech recognition with CIs. This study examined the relations in CI users between visual measures of VL&M and speech recognition in a series of models that also incorporated spectro-temporal discrimination. Predictions were that (1) speech recognition would be associated with VL&M abilities and (2) VL&M would contribute to speech recognition outcomes above and beyond spectro-temporal discrimination in multivariable models of speech recognition. Methods: This cross-sectional study included 30 adult postlingually deaf experienced CI users who completed a nonauditory visual version of the California Verbal Learning Test-Second Edition (v-CVLT-II) to assess VL&M, and the Spectral-Temporally Modulated Ripple Test (SMRT), an auditory measure of spectro-temporal processing. Participants also completed a battery of word and sentence recognition tasks. Results: CI users showed significant correlations between some v-CVLT-II measures (short-delay free- and cued-recall, retroactive interference, and "subjective" organizational recall strategies) and speech recognition measures. Performance on the SMRT was correlated with all speech recognition measures. Hierarchical multivariable linear regression analyses showed that SMRT performance accounted for a significant degree of speech recognition outcome variance. Moreover, for all speech recognition measures, VL&M scores contributed independently in addition to SMRT. Conclusion: Measures of spectro-temporal discrimination and VL&M were associated with speech recognition in CI users. After accounting for spectro-temporal discrimination, VL&M contributed independently to performance on measures of speech recognition for words and sentences produced by single and multiple talkers.
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    Reconstruction of midface defect from idiopathic destructive process using Medpor implant
    (Elsevier, 2017-05) Franko, Joel; Harris, Michael S.; Vernon, Dominic; Shipchandler, Taha Z.; Otolaryngology -- Head and Neck Surgery, School of Medicine
    Importance Reconstruction of the midface remains a challenging task for even the most experienced surgeon, with a host of reconstructive options including free tissue transfer, allografts, or prosthetic implants. Presented here is a case of idiopathic bony destruction of the right midface in a 19 year old female, creating a unique defect requiring repair. Objective Demonstrate a unique case of severe maxillary degeneration and discuss the associated reconstructive challenges and final repair with a prosthetic implant. Design Case report. Results The patient presented with a 7 month history of an idiopathic progressive deformity of the right cheek. Computed tomography of the paranasal sinuses revealed extensive bone loss of the right midface and orbit. The patient underwent facial reconstruction using a customized Medpor (Stryker Corp, Kalamazoo, MI) implant. At 6 month follow-up the patient and physician were both pleased with the patient's overall appearance. The patient did have some residual lower lid retraction present as well as some lateral pull at the lateral canthus outward from the orbit itself. Conclusions Preoperative planning for midface reconstruction requires a deep understanding of the aesthetic, functional, and supportive roles this structure holds. Computer assistance allows the creation of custom made implants, providing the reconstructive surgeon with innovative options for reconstruction with minimal morbidity to the patient. As the technology around the design and creation of the custom implants continues to improve, the role of computer assistance in reconstruction will become more prominent.
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    Three challenges for future research on cochlear implants
    (Elsevier, 2018-01-02) Pisoni, David B.; Kronenberger, William G.; Harris, Michael S.; Moberly, Aaron C.; Otolaryngology -- Head and Neck Surgery, School of Medicine
    Cochlear implants (CIs) often work very well for many children and adults with profound sensorineural (SNHL) hearing loss. Unfortunately, while many CI patients display substantial benefits in recognizing speech and understanding spoken language following cochlear implantation, a large number of patients achieve poor outcomes. Understanding and explaining the reasons for poor outcomes following implantation is a very challenging research problem that has received little attention despite the pressing clinical significance. In this paper, we discuss three challenges for future research on CIs. First, we consider the issue of individual differences and variability in outcomes following implantation. At the present time, we still do not have a complete and satisfactory account of the causal underlying factors that are responsible for the enormous individual differences and variability in outcomes. Second, we discuss issues related to the lack of preimplant predictors of outcomes. Very little prospective research has been carried out on the development of preimplant predictors that can be used to reliably identify CI candidates who may be at high risk for a poor outcome following implantation. Other than conventional demographics and hearing history, there are no prognostic tools available to predict speech recognition outcomes after implantation. Finally, we discuss the third challenge - what to do with a CI-user who has a poor outcome. We suggest that new research efforts need to be devoted to studying this neglected clinical population in greater depth to find out why they are doing poorly with their CI and what novel interventions and treatments can be developed to improve their speech recognition outcomes. Using these three challenges as objectives for future research on CIs, we suggest that the field needs to adopt a new narrative grounded in theory and methods from Cognitive Hearing Science and information processing theory. Without knowing which specific biological and neurocognitive factors are responsible for individual differences or understanding the underlying sensory and neurocognitive basis for variability in performance, it is impossible to select a specific approach to habilitation after a deaf adult or child receives a CI. Deaf adults and children who are performing poorly with their CIs are not a homogeneous group and may differ in many different ways from each other, reflecting the dysfunction of multiple brain systems associated with both congenital and acquired deafness. Hearing loss is not only an ear issue, it is also a brain issue too reflecting close links between perception and action and brain, body and world working together as a functionally integrated information processing system to support robust speech recognition and spoken language processing after implantation.
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    Verbal Learning and Memory After Cochlear Implantation in Postlingually Deaf Adults: Some New Findings with the CVLT-II
    (Wolters Kluwer, 2018) Pisoni, David B.; Broadstock, Arthur; Wucinich, Taylor; Safdar, Natalie; Miller, Kelly; Hernandez, Luis R.; Vasil, Kara; Boyce, Lauren; Davies, Alexandra; Harris, Michael S.; Castellanos, Irina; Xu, Huiping; Kronenberger, William G.; Moberly, Aaron C.; Biostatistics, IU School of Medicine
    OBJECTIVES: Despite the importance of verbal learning and memory in speech and language processing, this domain of cognitive functioning has been virtually ignored in clinical studies of hearing loss and cochlear implants in both adults and children. In this article, we report the results of two studies that used a newly developed visually based version of the California Verbal Learning Test-Second Edition (CVLT-II), a well-known normed neuropsychological measure of verbal learning and memory. DESIGN: The first study established the validity and feasibility of a computer-controlled visual version of the CVLT-II, which eliminates the effects of audibility of spoken stimuli, in groups of young normal-hearing and older normal-hearing (ONH) adults. A second study was then carried out using the visual CVLT-II format with a group of older postlingually deaf experienced cochlear implant (ECI) users (N = 25) and a group of ONH controls (N = 25) who were matched to ECI users for age, socioeconomic status, and nonverbal IQ. In addition to the visual CVLT-II, subjects provided data on demographics, hearing history, nonverbal IQ, reading fluency, vocabulary, and short-term memory span for visually presented digits. ECI participants were also tested for speech recognition in quiet. RESULTS: The ECI and ONH groups did not differ on most measures of verbal learning and memory obtained with the visual CVLT-II, but deficits were identified in ECI participants that were related to recency recall, the buildup of proactive interference, and retrieval-induced forgetting. Within the ECI group, nonverbal fluid IQ, reading fluency, and resistance to the buildup of proactive interference from the CVLT-II consistently predicted better speech recognition outcomes. CONCLUSIONS: Results from this study suggest that several underlying foundational neurocognitive abilities are related to core speech perception outcomes after implantation in older adults. Implications of these findings for explaining individual differences and variability and predicting speech recognition outcomes after implantation are discussed.