Announcing 2018 Capita Foundation Auditory Research (CFAR) grant award recipients

Daniel A. Llano, M.D., Ph.D.

University of Illinois at Urbana & Champaign

Project Title:  “An exercise intervention to prevent aging-related hearing loss in a mouse model.”

In our research program, we will examine the impact of aging on the auditory system. We will focus on developing innovative approaches to measure metabolic changes in the aging auditory system and developing novel interventions to mitigate them. Successful completion of this work will lead to new approaches to preserve hearing as we age.

Josée Lagacé, Ph.D. and Benoît Jutras , Ph.D.

University of Ottawa

Project Title:  "Virtual Reality For Auditory Training Therapy: A Pilot Study"

Virtual reality (VR) allows an individual to interact in real time with a three-dimensional, computer-simulated environment. The objective of this pilot study is to evaluate VR as an effective interface for ensuring uptake and motivation to auditory training in children with auditory processing difficulties. Since many children with auditory processing difficulties also have learning problems at school, this approach could also contribute to the enhancement of their learning experience and as well as to a reduction of schooling failure.

Madhu Sundarrajan, Ph.D.

University of the Pacific

Project Title:   “Audiological and Communication Outcomes in Children with Unilateral Hearing Loss: A Pilot Study.”

Unilateral hearing loss (UHL) or single-sided deafness is a type of hearing impairment where individuals have typical hearing in one ear and impaired hearing in the other ear. Permanent UHL exists when the average pure tone air conduction threshold at 0.5, 1, and 2 kHz is greater than or equal to 20 dB HL or pure tone air conduction thresholds are greater than 25 dB HL at two or more frequencies above 2 kHz in the affected ear with an average pure tone air conduction threshold in the good ear less than or equal to 15 dB (National Workshop on Mild and Unilateral Hearing Loss 2005). It is estimated that 1/3 of children with hearing loss are diagnosewith UHL (Lieu, 2018).

Historically UHL was typically not treated in children with the presumption that the contra-lateral ear with hearing levels within the typical range will suffice in providing adequate acoustic stimuli for development of speech perception and communication skills (Oyler, Oyler & Matkin, 1987). However, recent research has shown that children with untreated UHL have poorer communication and academic outcomes compared to typical hearing (TH) children (Kishon-Rabin, Kuint, Hildesheimer, & Ari-Even, 2015, Fitzpatrick et al., 2018; Lieu, 2018), indicating that children with UHL may benefit from an amplification device fitted to the poorer ear.

This project aims to ameliorate the critical gap in the literature by comprehensively investigating audiological and communication outcomes in children with UHL. Furthermore, this project will provide vital information regarding clinical recommendations for children with UHL, in order for them to maintain age appropriate auditory, communication and academic outcomes.

Matthew J. Wilson, Ph.D.
Northern Illinois University

Project Title:  “Relationship Between Cognitive Changes and Speech-in-Noise Deficits in Individuals with a History of Concussion: An Efferent System Study.” 

It is well known that long-standing cognitive deficits in the areas of attention and memory frequently accompany concussion. The role that these cognitive deficits play in the development of auditory processing difficulties, such as trouble understanding speech in noise (SIN), following injury remains unclear. Processing auditory information requires a complex interaction between afferent and efferent auditory pathways. The nature of the relationship is such that afferent information, which travels from cochlea to cortex, can be modulated by top-down, cortical influences via feedback loops in the efferent system (ES). These loops are integral for a variety of auditory skills, like understanding SIN. ES strength can be non-invasively measured using a technique known as otoacoustic emission (OAE) suppression, which quantifies how well outer hair cell activity is suppressed in the presence of noise. Greater levels of suppression are indicative of stronger ES activation and have been shown to correlate with better auditory comprehension abilities.

The interdependence of the cortex and efferent pathway suggests that alterations in cortical activity, like what is seen following concussion, may have an impact on overall suppression levels and, by default, play a role in the development of SIN difficulties; however, the nature of the relationship remains poorly understood. Thus, this study aims to examine the relationship between electrophysiological indices of cognition and SIN abilities and how those relate to changes in behavioral performance. Finding will not only improve audiological diagnosis, treatment, and rehabilitation options, but will also expand the role of the audiologist in the area of head injury research.

Philippe Vincent, Ph.D.

Johns Hopkins School of Medicine

Project jointly funded with Hearing Health Foundation
https://hearinghealthfoundation.org/

Project Title:   “Investigating mechanisms of degeneration of ribbon synapses between auditory inner hair cells and type 1 afferent nerve fibers after noise trauma in mammals.”

During all of our life, we are surrounded by sounds that include different frequencies and intensity levels. In the inner ear, the sensory hair cells pick up the sound signal and transmit it to auditory nerve fibers via chemical synapses by releasing the transmitter glutamate; and auditory nerve fibers transmit the sound-coding signal to the brain.

Sound intensity is encoded by the amount of glutamate released by the hair cell, leading to glutamate receptor activation and then action potential firing in auditory nerve fibers. During noise exposure, it has been described that auditory nerve fiber endings can be damaged short- or long-term, most likely due to and excess of calcium influx into the auditory nerve fiber endings. This phenomenon is called excitotoxicity, however, the underlying mechanisms are not completely understood.  

Here I propose to investigate molecular mechanisms of synaptic transmission between hair cells and auditory nerve fibers and to test how they are affected after noise trauma.

Valerio Magnaghi, Ph.D.

University of Milan

Project Title:  “Unrevealing mechanisms of Schwann cell in vestibular schwannoma and their impact on hearing loss.”

Vestibular Schwannoma is a benign tumor of the acoustic nerve causing hearing loss. It arises from Schwann cells, the main myelin-forming cells in the nerve. Thus, changes in the oncogenic properties of these cells may be involved in hearing loss.

The main goal of our project is to analyze the molecular mechanisms underlying the human Schwann cells oncogenic transformation, potentially responsible of the vestibular schwannoma onset, and their vulnerability to environmental electromagnetic fields, that in principle might be pathologically relevant for the hearing loss.

Saad M. Bhamla, Ph.D.

Georgia Tech University

Project Title:  “A low-cost, open-source and self-fitting hearing aid.”