DATE: Wednesday, March 19, 2025 at 1PM ET
SPEAKER: Ruth Litovsky, PhD, Oros Bascom Chair & Professor, Waisman Centre, Department of Communication Sciences & Disorders, University of Wisconsin
Abstract:
Binaural hearing is a critically important auditory process which enhances our ability to navigate in noisy, complex listening environments. Bilateral cochlear implants are provided to a growing number of children, and adults, depending on the standard of care and insurance coverage. Bilateral hearing typically improves localization of sounds and segregation of speech from background noise compared with unilateral hearing. However, patients typically perform worse than normal hearing listeners. We use several approaches to understand factors that contribute to reduced performance in individuals with BiCIs. One factor is the asymmetry in hearing across the ears, which reduces how well information across the two ears is integrated, fused, and leads to good spatial hearing. A second factor is difference across the ears in neural health; poor neural health can include many aspects of reduced ability of the neural element to encode and transmit information with fidelity. In the binaural system, poor neural health in one of the two ears can promote a ‘bottleneck’ for information processing, meaning that even if one ear transmits good information, lack of fidelity in the other ear promotes poor binaural hearing. Because CI processors do not preserve binaural cues with fidelity, we use research processors to generate multi-channel binaural stimulation strategies that introduce different rates of stimulation across the electrode arrays, thereby preserving rates that are important for both binaural sensitivity and speech understanding. In addition, eye gaze studies reveal developmental factors that in decision-making that are not observed with measures of threshold. Finally, pupillometry studies provide insight into the impact of integrating inputs from two ears, whereby in some instances improved performance with two ears can be “costly” in the listening effort domain.
Learning Objectives
- Understand binaural hearing processes in individuals with normal hearing, and limitations in individuals with hearing loss.
- Understand current outcomes in individuals with bilateral cochlear implants and limitations that need to be addressed.
- Understand future directions in improving outcomes in bilateral cochlear implants, including segregation of speech in noise, sound localization and reduction in listening effort.
SPEAKER: Ruth Litovsky, PhD, Oros Bascom Chair & Professor, Waisman Centre, Department of Communication Sciences & Disorders, University of Wisconsin
Ruth Litovsky, PhD, is Oros Family chair in the Department of Communicative Sciences and Disorders at the University of Wisconsin – Madison. She has a joint appointment in the Division of Otolaryngology in the Department of Surgery, and serves as the Academic Associate Dean for the Division of Natural, Physical & Mathematical Sciences in the College of Letters & Science.
Ruth received her BA and MA degrees from Washington University in St. Louis (1987), PhD in Developmental Psychology under the mentorship of Rachel Clifton (Keen) in from the University of Massachusetts-Amherst (1991), and then forged into the world of auditory neuroscience where she trained with Tom Yin as a postdoctoral fellow at the University of Wisconsin-Madison (1991-1994). She spent the next seven years combining studies in human behavior and auditory neuroscience, at Boston University in Steve Colburn’s lab, and at the Massachusetts Eye and Ear Infirmary.
Scientifically, Ruth’s work has revealed fundamental insights into the perceptual capabilities of binaural and spatial hearing in human listeners. During much of her career, she studied sound localization, binaural hearing, source separation, speech intelligibility, echo suppression and how experience and impacts perception and auditory development. Since joining the faculty at the University of Wisconsin-Madison (2001), her research has focused primarily on auditory function in children and adults with bilateral cochlear implants, with an eye towards ultimately improving outcomes in cochlear implant users. In recent years, Ruth has also embarked on studies in individuals with single-sided deafness, and a very new area of research on individuals with Down Syndrome to understanding hearing loss, cognition, language and brain structure. Ruth’s lab is unique in that the approaches that are used to delve into novel scientific inquiry are ever evolving. While they include psychophysics and reverse engineering to explore how binaural hearing can be restored cochlear implant users with fidelity, pupillometry and eye gaze measures are harnessed to examine ‘real time’ processing of information and listening effort during perceptual tasks. More recently, the lab has begun to implement functional neuroimaging to investigate neural signatures for bilateral benefits and cognitive load.
Ruth is passionate about mentoring and service to her community. She has served on numerous committees and panels at her home institution and in service to scientific organizations. She believes that the only way to conduct research through the mentorship of students and postdocs, as well as through collaboration with colleagues around the world. She attributes the outcomes of her research program, the success of the lab and impact of the work to her scientific family and the many long-lasting relationships forged through teaching, mentoring and collaboration. The energy and passion that Ruth puts into her science is matched by her commitment to diversity, equity, inclusion and belonging, as well as mentorship. She has devoted much of her career to developing mentoring programs at scientific conferences and organizations and has helped organizations adopt best practices to address systemic problems.
Ruth’s recognition for her scientific achievements can be seen in her sustained record of research excellence. Her ongoing research program has been continuously funded by grants from NIH-NIDCD since 1995, in addition to grants from smaller foundations and collaborative projects with cochlear implant companies. She has published over 150 papers and book chapters based on her research which focuses hearing abilities covering lifespan of humans to include infants and elderly adults.
Ruth has received several awards during her career. She was the first woman to receive the Silver Medal from the Acoustical Society of America. She was honored with Carhart Memorial Lecture of the American Auditory Society, was a Fulbright Senior Fellow, Elected Fellow of the Acoustical Society of America, was President the Association for Research in Otolaryngology, elected chair of the Auditory System Gordon Research Conference, invited to give the 2024 American Cochlear Implant Alliance Keynote honoring the life and career of Dr. John Niparko. and is now the Editor in Chief of the journal Ear and Hearing.
