DIAGNOSING IMPAIRED BAND ACCESS IN PATIENTS WITH COCHLEAR IMPLANTS

About This Grant

PROJECT SUMMARY/ABSTRACT Speech recognition outcomes greatly vary across individuals who hear with cochlear implants. This variability is a major problem because many individuals undergo a costly and invasive surgery only to fall short of the potential benefits that their implant could provide. Many mechanisms have been hypothesized to impair transmission of speech information. These mechanisms vary across individuals and across stimulation sites within an ear, so they could account for variable outcomes. Determining how this variability within an ear affects speech recognition requires a tool to measure how access to speech cues varies across the speech spectrum. We have developed an assessment of access to speech cues by analyzing the acoustic structure of speech used in common clinical tests. Using this assessment reveals that individual variability in access to speech cues across frequencies predicts speech recognition outcomes in patients with cochlear implants. The proposed work builds on this finding to identify factors that affect access to speech cues in this frequency band. Across three specific aims, we will examine the relationships between band access and patient properties, properties of the processor and electrode-nerve interface, and listening conditions. Aim 1: Establish an assessment of individual differences in band access in CI users. Aim 2: Identify mechanisms that produce poor band access. Aim 3: Identify effects of stimuli and listening condition on band access. In Aim 1, we will establish normative ranges and reliability for band access measures by examining data collected in the clinic and experimentally by our lab. In Aim 2, we will assess how band access depends on properties of the listener’s signal processing strategy and auditory nerve to identify intervention strategies. In Aim 3, we will test whether measures of band access generalize across a variety of speech stimuli and listening conditions, which would determine the need to tailor processing strategies to optimize access to speech cues in specific conditions. Completing these aims will provide a clinically feasible assessment for identifying regions of poor band access. This assessment will facilitate the development of a precision medicine approach to intervention for patients with cochlear implants, which is a high priority research area for NIDCD. This work will form the basis for the design of clinical tools for personalized assessment and intervention to address suboptimal speech recognition outcomes in patients with cochlear implants.