General Hearing Health
Hearing Health Foundation’s Emerging Research Grants (ERG) program awards grants to researchers working across the entirety of the hearing and balance field, including:
Physiology of hearing and balance
Epidemiology of auditory and vestibular disorders
Human otopathology
Diagnosis, treatment and prevention of hearing loss and balance disturbance
Human genetics and mouse models of peripheral and central auditory/balance dysfunction
Innovation in cellular and molecular therapies
Auditory and vestibular implants, and hearing aids
The Elizabeth M. Keithley, Ph.D. Early Stage Investigator Award is a grant opportunity open to early stage investigators (ESI). HHF defines ESIs as being no more than 10 years removed from the most recent terminal degree or medical residency. There are additional eligibility requirements for this grant opportunity—please see the full Policy on Emerging Research Grants for details.
ERG awards are for up to $50,000 per year, one year in length in the first instance, and renewable for a second year. Find more information below about projects awarded a grant in prior years.
Researchers interested in applying for an Emerging Research Grant are encouraged to review our grant policies, subscribe to alerts, and check our ERG page for application cycle dates and specific grant opportunities available this year.
Recent Funded Projects
University of Michigan
Novel mechanisms of cortical neuromodulation
Although there is currently no cure for tinnitus, recent experimental studies propose vagus nerve stimulation (VNS) may be a potential treatment to mitigate the condition because VNS releases natural chemicals (neuromodulators) that increase the brain’s ability to change. This is interesting because VNS has previously received Food and Drug Administration approval for treating drug-resistant epilepsy and treatment-resistant major depressive disorder. Despite considerable interest, how neuromodulators released by VNS could be therapeutically useful for tinnitus is unknown. This project will employ cutting-edge techniques to test a novel hypothesis: A major mechanism of action for neuromodulators is that they affect the function of dendrites, the long cable-like structures upon which neurons receive and integrate electrical signals. By identifying how neuromodulators impact the function of dendrites, these experiments may uncover novel targets for developing new treatments for tinnitus.
New York University
Defining myelin’s role in developing vestibular circuits
The vestibular system serves a vital purpose, to stabilize posture and gaze by producing corrective head and body movements. Vestibular circuits are myelinated early in life, suggesting a crucial role in proper balance development. In addition, balance, posture, and gait deficits are common symptoms for patients affected by diseases where myelin breaks down. Myelination alters conduction velocity thus it is crucial for circuit function. Recent studies have shown that the formation of novel myelin plays an essential role in memory formation and learning. The overall goal of this project is to define a role for myelin in vestibular circuit development and postural behaviors. We will investigate the consequences of loss of vestibular myelin on postural development. The work will also establish and validate transformative new tools to selectively disrupt the myelination of genetically defined subsets of neurons. I will test the role of myelin in different circuits for postural behavior, locomotion, and coordination in order to understand myelin’s contributions to circuit function. These novel tools will also permit future investigations into the role of myelin in auditory circuits and the consequences for hearing health.
University of Colorado Boulder
Hearing loss and cardiovascular disease risk burden: epidemiological and physiological data
Although hearing loss is often considered in isolation, recent evidence points toward comorbidity with other conditions including cardiovascular disease (CVD). Both hearing loss and CVD are prevalent chronic conditions, and the auditory system has a demonstrated vulnerability to cardiovascular-related diseases. Given that audiologists are likely to see patients with co-occurring conditions, a better understanding of CVD risk factors is useful. This study will use, for the first time, the notion of risk burden to explore the link between CVD and hearing loss in a large dataset, and will examine the link using specific measures of auditory status in a cross-sectional study. Through the use of cost-effective, clinically available techniques in conjunction with epidemiological data, a greater understanding of CVD risk factors that contribute to hearing loss will be a key toward prevention, early identification, and treatment.
University of Washington
Aminoglycoside compartmentalization and its role in hair cell death
The goals for this project are to develop new tools that will help the scientific community to deepen our understanding of the vesicular network in hair cells, both during stress and normal conditions. We will develop novel fluorescent probes to mark the different compartments in the vesicular network. This will allow for visualization of the drug as it transitions through various levels within the vesicular network. In order to better analyze these structures, we will pair these images with custom-made image analysis algorithms that will allow us to study vesicles in a deeper way. Overall, these tools will allow us to open new research avenues that will help to further understand how aminoglycosides, and other drugs with ototoxic effects, like cisplatin, a cancer chemotherapy drug, are killing hair cells. Our results could help direct new research and lead to novel therapeutic treatments to avoid further hearing loss in patients undergoing these treatments.
Oregon Health & Science University
Apical cochlear mechanics after cochlear implantation
The long-term research goal is to establish, treat, and prevent cochlear implantation-induced hearing loss. This mechanics project is the first time the vibration of the inner ear has been measured in the presence of a cochlear implant, and there is much to discover—such as measuring the efficacy of drugs that help to suppress scarring, as well as testing different electrode designs, and even extending to other diseases of the inner ear such as Ménière’s disease. I believe that optical coherence tomography has a big role to play in the future of both basic hearing science and hearing restoration.
University of Minnesota
Behavioral and neural correlates of amplification outcome
Understanding individual factors, beyond hearing thresholds, that account for the high variability in success in the use of hearing aids is an important question with immediate clinical implications. This project aims to evaluate how fundamental aspects of auditory processing interact with high-intensity sounds and influence hearing aid amplification outcomes. Behavioral and speech and non-speech measures will be used to determine how spectral auditory processing interacts with high intensity sounds and influences amplification. This will help us determine factors that contribute to diminished speech perception in noisy environments for individuals with hearing loss and how their perception of amplified speech can be enhanced in noisy environments.
University of Southern California
Filtering of otoacoustic emissions: a window onto cochlear frequency tuning
Healthy ears emit sounds that can be measured in the ear canal with a sensitive microphone. These otoacoustic emissions (OAEs) offer a noninvasive window onto the mechanical processes within the cochlea that confer typical hearing, and are commonly measured in the clinic to detect hearing loss. Nevertheless, their interpretation remains limited by uncertainties regarding how they are generated within the cochlea and how they propagate out of it. Through experiments in mice, this project will test theoretical relationships that suggest that OAEs are strongly shaped (or “filtered”) as they travel through the cochlea, and that this filtering is related to how well the ear can discriminate sounds at different frequencies. This may lead to novel, noninvasive tests of human cochlear function, and specifically frequency discrimination, which is important for understanding speech.
New York University School of Medicine
Neural computations for vestibular control of movement initiation
Loss of balance and falls are common in aging populations and associated with various neurological disorders. Balance is sensed using vestibular organs in the inner ear and processed in the brainstem. However, it remains unclear how the brainstem transforms sensations of instability into corrective movements that restore balance. The objective of this project is to define how cells in the brainstem act collectively to produce rapid responses to sensations of instability. In order to measure balance responses in populations of cells located deep within the brain, this project will apply cutting-edge microscopy techniques to the zebrafish. These fish swim to remain balanced, providing a model for balance control and brainstem function in general.
Mass Eye and Ear
Age-specific cochlear implant programming for optimal hearing performance
Cochlear implants (CI) offer life-altering hearing restoration for deafened individuals who no longer benefit from hearing aid technologies. Despite advances in CI technology, recipients struggle to process complex sounds in real-world environments, such as speech-in-noise and music. Poor performance results from artifacts of the implants (e.g., adjacent channel interaction, distorted signal input) and age-specific biological differences (e.g., neuronal health, auditory plasticity). Our group determined that children with CIs require a better signal input than adults with CIs to achieve the same level of performance. Additional evidence demonstrates that auditory signal blurring in adults is less impactful on performance outcomes. These findings imply that age should be considered when programming a CI. However, the current clinical practice largely adopts a one-size-fits-all approach toward CI management and uses programming parameters defined by adult CI users. Our project’s main objective is to understand how to better program CIs in children to improve complex sound processing by taking into context the listening environment (e.g., complex sound processing in a crowded room), differences between age groups, and variations in needs or anatomy between individuals.
Purdue University
Influence of individual pathophysiology and cognitive profiles on noise tolerance and noise reduction outcomes
Listening to speech in noisy environments can be significantly challenging for people with hearing loss, even with help from hearing aids. Current digital hearing aids are commonly equipped with noise-reduction algorithms; however, noise-reduction processing introduces inevitable distortions of speech cues while attenuating noise. It is known that hearing-impaired listeners with similar audiograms react very differently to background noise and noise-reduction processing in hearing aids, but the biological mechanisms contributing to that variability is particularly understudied.
This project is focused on combining an array of physiological and psychophysical measures to obtain comprehensive hearing and cognitive profiles for listeners. We hope this approach will allow us to explain individual noise tolerance and sensitivity to speech-cue distortions induced by noise-reduction processing in hearing aids. With these distinct biological profiles, we will have a deeper understanding of individual differences in listeners and how those profiles affect communication outcomes across patients who are clinically classified with the same hearing status. This study’s results will assist in the development of objective diagnostics for hearing interventions tailored to individual needs.
Washington State University Vancouver
Characterizing noise-induced synaptic loss in the zebrafish lateral line
Recent findings indicate that noise levels thought to be safe for auditory sensory hair cells may actually damage hearing at the level of peripheral auditory synapses. Little is known about this type of damage, which is usually not detectable using traditional audiograms and so has been dubbed “hidden hearing loss.” This project will study noise-induced hearing loss using zebrafish, where the auditory sensory cells are easily accessible and highly similar to those in humans, in order to uncover mechanisms of synaptic damage due to noise exposure. It will use a combination of techniques including immunohistochemistry and calcium imaging to directly examine the timing and extent of noise damage on peripheral auditory synapses.
New York University
A balancing act in hearing and vestibular loss: assessing auditory contribution to multisensory integration for postural control in an immersive virtual environment
Humans are surrounded by sensory information and need to select the most reliable ones in order to maintain balance and disregard input that might make us fall. This is called “weighting” and “reweighting” of sensory inputs. This project uses a virtual reality, head-mounted display (HMD) application to test balance with varying sensory cues, including visual, somatosensory, and auditory. With this application, an individual’s ability to weight and reweight visual and auditory information based on their head and eye movement and their postural sway can be identified. This method has been successfully used in prior studies to test responses to visual changes. The novelty of this project includes: the addition of auditory cues scaled to well-established visual cues; the measurement of head movement via the HMD; and the portability, simplicity, and affordability of the HMD system, which increases the likelihood of future clinical translation of this assessment. In this current pilot study, 12 individuals with unilateral sensorineural hearing loss will be compared with 12 individuals with unilateral peripheral vestibular hypofunction and with 24 healthy controls. Wearing the HMD, they will go through a series of postural tasks with several combinations of visual and auditory cues of two intensity levels while standing on either a stable floor (all somatosensory cues available) or a compliant foam (to reduce somatosensory input). Their postural sway and head movement responses to the stimuli will be calculated, and gaze patterns among the groups will be compared, along with exploring whether changes in eye position can explain changes in head movement.
University of Florida
Contributions of auditory and somatosensory feedback to speech motor control in congenitally deaf 9- to-10-year-olds and adults
Cochlear implants have led to stunning advances in prospects for children with congenital hearing loss to acquire spoken language in a typical manner, but problems persist. In particular, children with CIs show much larger deficits in acquiring sensitivity to the individual speech sounds of language (phonological structure) than in acquiring vocabulary and syntax. This project will test the hypothesis that the acquisition of detailed phonological representations would be facilitated by a stronger emphasis on the speech motor control associated with producing those representations. This approach is novel because most interventions for children with CIs focus strongly on listening to spoken language, which may be overlooking the importance of practice in producing language, an idea we will examine. To achieve that objective, we will observe speech motor control directly in speakers with congenital hearing loss and CIs, with and without sensory feedback.
The Ohio State University
Differentiating Ménière's disease and vestibular migraine using audiometry and vestibular threshold measurements
Patients presenting with recurrent episodic vertigo (dizziness), such as Ménière's disease (MD) and vestibular migraine (VM), can present a diagnostic challenge as they can both produce recurrent vertigo, tinnitus, motion intolerance, and hearing loss. Further complicating this issue is that the diagnosis of each is based upon patient history with little contribution from an objective measure. Previous attempts to better differentiate MD and VM have included a variety of auditory and vestibular tests, but these evaluations have demonstrated limitations or not shown the appropriate sensitivity and specificity to be used in the clinical setting. Recently, vestibular perceptual threshold testing has shown the potential to better differentiate MD and VM by demonstrating different and opposite trends with testing, and these evaluations are ongoing. In addition to vestibular evaluations, audiometry (hearing testing) is a mainstay of testing in those with vestibular symptoms, especially with any concern of MD, and is thus commonly available. Standard hearing testing, however, is not sensitive or specific enough alone to differentiate MD and VM, but this project’s hypothesis is that combining audiograms with vestibular perceptual threshold testing will result in a diagnostic power greater than that possible with either option used individually. The population of patients with MD and VM is an ideal setting to examine similarities and differences, as MD is classically an otologic disease and VM, in theory, has little to do with auditory function. Additionally, this same principal can be applied to any disease process that affects both vestibular and auditory function (such as tumors, ototoxicity).
University of Pittsburgh
Hair cell regeneration in the mature cochlea: investigating new models to reprogram cochlear epithelial cells into hair cells
Sensory hair cells in the inner ear detect mechanical auditory stimulation and convert it into a signal that the brain can interpret. Hair cells are susceptible to damage from loud noises and some medications. Our lab investigates the ability of nonsensory cells in our inner ears to be able to regenerate lost hair cells. We regenerate cells in the ear by converting nonsensory cells into sensory cells through genetic reprogramming. Key hair cell-inducing program genes are expressed in non-hair cells and partially convert them into hair cells. There are multiple types of nonsensory cells in the inner ear and they are all important for different reasons. In addition, they are in different locations relative to the sensory hair cells. In order to better understand the ability of different groups of cells to restore hearing, we need to be able to isolate different populations of cells. The funded project will allow us to create a new model to target specific nonsensory cells within the inner ear to better understand how these cells can be converted into hair cells. By using this new model, we can specifically investigate cells near the sensory hair cells and understand how they can be reprogrammed. Our lab is also very interested in how the partial loss of genes in the inner ear can affect cellular identities. In addition to targeting specific cells in the ear, we will investigate whether the partial loss of a protein in nonsensory cells may improve their ability to be converted into sensory cells. This information will allow us to further explore possible therapeutic targets for hearing restoration.
Rice University
Understanding the biophysics and protein biomarkers of Ménière’s disease via optical coherence tomography imaging
Our sense of hearing and balance depends on maintaining proper fluid balance in a specialized fluid in the inner ear called the endolymph. Ménière’s disease is an inner ear disorder associated with increased fluid pressure in the endolymph that involves dizziness, hearing loss, and tinnitus. Ménière’s disease is difficult to diagnose and treat clinically, which is a source of frustration for both physicians and patients. Part of the barrier to diagnosing and treating Ménière’s disease is the lack of imaging tools to study the inner ear and a poor understanding of the underlying causes. The goal of this research is to develop an approach to noninvasively image the inner ear and study the internal structures in the vestibular system in typical and disease states. We will utilize optical coherence tomography (OCT), a technique capable of imaging through bone, and observe changes in the fluid compartments in the inner ear. The expected outcome of this research will be the establishment of a powerful non-invasive imaging platform of the inner ear that will enable us to test hypotheses, in living animals, on how ion transport regulates the endolymph, how disorders of ion transport cause disruption of endolymphatic fluid, and how the expression of different biomarkers lead to disorders of ion transport.
National Cancer Institute
High-dimensional analysis of cochlear immunity and cisplatin-induced inflammation
Cisplatin is a life-saving chemotherapy drug but has serious side effects, including causing hearing loss in 40 to 80 percent of cancer patients. Cisplatin enters the cochlea through systemic circulation and gains access to inner ear sensory hair cells after disrupting the protective blood-labyrinth-barrier (BLB). A damaged BLB also means a greater invasion of CD45(+) leukocytes (white blood cells), causing inflammation and, ultimately, hearing loss. We hypothesize that a defined subset of innate immune cells regulates hair cell death by controlling cisplatin-induced inflammatory pathways within the cochlea. Our preliminary data suggest that the cochlea has a different amount of defined leukocytes compared with blood-borne leukocytes. In addition, the data suggest that immune cells that regulate cochlear inflammation may play a role in overall ototoxicity. Understanding cochlear immunity and the interaction of immune cells with other sensory cells will shed light on ototoxicity research and its prevention.
University at Buffalo, the State University of New York
Targeting microglial activation in hyperacusis
Hyperacusis is a hearing condition in which moderate-level noise becomes intolerable. The Centers for Disease Control estimates that nearly 6 percent of the U.S. population experiences some form of hyperacusis, ranging from mild discomfort to severe medical disability, with a diminished quality of life. There is currently no cure for hyperacusis. Therefore, there is a pressing medical need for targeted treatment approaches for the permanent relief of hyperacusis. This study will focus on the involvement of inflammation in the sound processing centers of the brain following noise exposure by using anti-inflammatory drugs to attempt to reduce inflammation and prevent hyperacusis after noise exposure. Results from this study will test the feasibility of anti-inflammatory drugs as a potential therapy for hyperacusis and hearing loss caused by excessive noise exposure.
University of Miami Miller School of Medicine
Elucidating the development of the otic lineage using stem cell-derived organoid systems
One of the main causes of hearing loss is the damage to and/or loss of specialized, cochlear hair cells and neurons, which are ultimately responsible for our sense of hearing. Stem cell–derived 3D inner ear organoids (lab-grown, simplified mini-organs) provide an opportunity to study hair cells and sensory neurons in a dish. However, the system is in its infancy, and hair cell–containing organoids are difficult to produce and maintain. This project will use a stem cell–derived 3D inner ear organoid system as a model to study mammalian inner ear development. The developmental knowledge gained will then be used to optimize the efficacy of the organoid system. As such, the results will progress our understanding of how the inner ear forms and functions, with the improved organoid system then allowing us directly to elucidate the factors causing the congenital hearing loss.
University of Kentucky
TRPA 1 activation in the cochlea as an intrinsic mechanism of protection against noise-induced hearing loss
TRPA1 is an ion channel mostly known for its role as an “irritant sensor” in pain-sensing neurons. Functional TRPA1 channels are also expressed in the inner ear. However, given that genetically modified mice lacking TRPA1 channels have typical hearing and balance, the role of these channels in the inner ear remains unknown. Noise exposure leads to the production of some of the cellular “irritants” that activate TRPA1 channels. Therefore, we hypothesized that TRPA1 channels are able to sense noise-induced damage in the cochlea. When we exposed adult mice to mild noise levels, we observed a temporary increase in hearing thresholds that lasted several days (making it harder to hear soft sounds). Mice lacking TRPA1 channels, however, recovered significantly faster than mice with typical TRPA1 expression. This project will explore whether, after noise exposure, TRPA1 activation contributes to the temporary shift in hearing thresholds to allow the cochlea enough time to repair or recover from the noise-induced tissue damage. This project will help us better understand the protective effects of TRPA1 activation after noise exposure, and the specific cell types within the inner ear that are involved in this process.
Mass Eye and Ear, Harvard Medical School
Targeting epigenetics to restore hair cells
Most commonly, deafness is due to loss of cochlear sensory hair cells, which can occur because of genetic diseases, loud noise, certain drugs, or aging, and it can also result in the development of sometimes disabling ringing in the ear (tinnitus) and sound sensitivity (hyperacusis). Balance disorders similarly arise from loss of respective sensory hair cells in the inner ear vestibular organ. Treatments aimed at reversing hearing loss by stimulating the recovery of hair cells are greatly needed. The death of these hair cells in the ear is permanent because the inner ear loses its ability to replenish lost cells once it has matured, which occurs shortly after birth in mice and in the fetus in humans. To reestablish this potential and to recover lost hair cells, this project uses a novel technology to reprogram stem cells from the inner ear to turn into hair cells. This has pointed to a new candidate drug target, lysine-specific demethylase 1 (Lsd1), an epigenetic regulator that appears to be at least partly responsible for this loss of regenerative capacity. By targeting Lsd1, this project will study its role in the formation of hair cells and investigate its potential as a drug target for treatment of hearing loss.