Karen Iler Kirk PhD, Hearing Science, The University of Iowa –Speech perception & cochlear implants Professor, Dept. of Speech, Language and Hearing Sciences Adjunct Professor, Dept. of Otolaryngology – Head and Neck Surgery, Indiana University School of Medicine (IUSM) Funding from NIH

Current Research Areas Collaborative Research: IUSM / Purdue (funded by NIH-NIDCD) Cochlear Implant (CI) Outcomes –Neural plasticity & sensory aid benefit Effects of early auditory and linguistic experience –Combined acoustic and electric hearing –CI outcomes in children with multiple handicapping conditions Spoken Word Recognition (SWR) in Listeners with Hearing Loss –Lexical and indexical effects on SWR –Multimodal SWR –Development of pediatric auditory-only tests of SWR Theoretically motivated by current models of spoken word recognition

Methodologies CI Outcomes Research Longitudinal assessments of auditory, speech and language abilities in children with prelingual deafness –Data are analyzed as a function of Type of sensory aid (hearing aid vs. cochlear implant) Age at implantation (1 st, 2 nd, or 3 rd year of life) Communication method (spoken vs. signed and spoken English) Degree of hearing loss Studies of Spoken Word Recognition Cross-sectional assessments of SWR in listeners with normal hearing and with hearing loss –Data are analyzed as a function of Stimulus characteristics (stimulus variability, lexical difficulty) Listener characteristics (age, hearing status) Test environment (quiet vs. competing noise)

Recent Results CI Outcomes Research Early implantation (<2 years) and early exposure to spoken language –Enhance spoken word recognition –Minimize language delays For children with some residual hearing in the non-implanted ear, the combined use of a CI and a hearing aid on opposite ears yields better SWR than either sensory aid alone, especially in noise Pediatric CI users with mild cognitive delays demonstrate similar speech perception skills, but delayed language skills, when compared to their typically developing deaf peers with CIs Studies of Spoken Word Recognition Despite receiving a degraded auditory signal, children with CIs –Organize and access words from lexical memory in a manner similar to listeners with normal hearing –Are sensitive to talker characteristics in the speech signal

Future Directions Translational Research Multidisciplinary effort to develop audiovisual tests of spoken word and sentence recognition –Proposed test features Lexically-controlled stimulus items “Perceptually robust” to reflect real-world listening demands (multiple talkers, speaking rates, etc.) Three presentation formats – Auditory only, Visual only and A + V Adult and pediatric versions Multi-site cross-sectional studies to: –Validate the new test –Collect normative data from adults and children with hearing loss Data analyzed by –Age –Degree of hearing loss –Type of sensory aid