Impact 2023

Hearing Health Foundation’s mission to fund innovative, groundbreaking hearing and balance science is only possible because of you. Thank you very sincerely for your support.

The Hearing Restoration Project (HRP) is an international, collaborative research consortium focused on investigating inner ear hair cell regeneration using animal models to accelerate the timeline to a cure for hearing loss and tinnitus.

The Emerging Research Grants (ERG) program provides seed money to scientists researching underfunded areas of hearing and balance science, and for every dollar HHF invests, grantees receive on average $56 in major federal funding (2002–present).

Your generous support produced the following significant achievements this past year:

Viji Easwar, Ph.D., found that the use of neural responses to sound to infer how well hearing aids—a common first form of intervention—provide access to speech is similar in children to that found in adults. In a related paper, her results demonstrated that neural responses were sensitive to the improved audibility provided by hearing aids among the 5- to 17-year-old children assessed. Easwar’s 2019 Emerging Research Grant was funded by the Children’s Hearing Institute.

Anat Lubetzky, PT, Ph.D., studies how varied sensory inputs—vision as well as hearing, in one ear or two—affect our ability to stay balanced and describes how “a guarding behavior" affecting balance is found in patients with hearing loss in one ear.

Khaleel Razak, Ph.D., published a report showing how data in aging mice strongly suggests that topical or oral nicotine or nicotine-like substances may be profoundly beneficial for aging humans with central auditory processing disruptions. Razak is a 2009 and 2018 Emerging Research Grants scientist. His 2018 grant was generously funded by Royal Arch Research Assistance.

Joseph Bochner, Ph.D., published a paper showing the apparent benefits of cochlear implantation before age 2. Bochner’s 2017 Emerging Research Grant was generously funded by Royal Arch Research Assistance.

Concluding a string of three publications in 2021 and 2022 that establish a baseline for investigating the molecular mechanisms of auditory hair cell regeneration in the chick model, Stefan Heller, Ph.D., identified genes that define three different sensory hair cell types and two distinct supporting cell groups in the chicken utricle, a balance organ. 

Andy Groves, Ph.D., and Yehoash Raphael, Ph.D., identified molecular barriers to overcome for hair cell regeneration in the adult mouse cochlea. Their work suggests that reprogramming with multiple transcription factors is better able to access the hair cell differentiation gene regulatory network, but that additional interventions may be necessary to produce mature and fully functional hair cells.

James Dewey, Ph.D., found that hearing involves highly distorted processing of sound by sensory hair cells. The research clarifies how distortions are produced by the outer hair cells and how these additional signals may influence peripheral sound encoding. He also found that distortion-product otoacoustic emissions may provide a noninvasive window onto cochlear frequency tuning, enhancing its utility for detecting and diagnosing hearing loss.

Robert Raphael, Ph.D., uncovered how a unique, fast synapse keeps us from falling. These specialized synapses process signals faster than any other in the human body.

Bryan K. Ward, M.D., had a trio of studies furthering understanding of Meniere’s disease and its treatment. He found the size of the semicircular canal in some Ménière's disease ears was smaller than the control ears, a potential explanation for divergent test results in the condition. He also found an inverse relationship between membrane thickness and fluid buildup, helping us better understand how fluid buildup occurs in Ménière's disease. A historical review of Ménière's disease treatments detailed the use of surgery and betahistine.

James Dias, Ph.D., found that a method to measure neuroplasticity is unreliable, which is important for developing reliable, noninvasive, and affordable techniques to study hearing loss, vision loss, and neuroplasticity. Dias’s 2022 Emerging Research Grant was generously funded by the Meringoff Family Foundation and renewed for a second year in 2023. 

Julia Campbell, Ph.D., Au.D., showed how sensory gating may aid in better perception of speech in noise, by acting as an automatic “filter” that may suppress noise before reaching levels of attention. This can help test the hypothesis that tinnitus perception may arise from faulty gating mechanisms in the brain. Her 2016 Emerging Research Grant was generously funded by the Les Paul Foundation.

David Raible, Ph.D., found that inner ear cell types between fish and mammals show similarities, validating the zebrafish as a relevant model for understanding inner ear-specific hair cell function and regeneration.

Hari Bharadwaj, Ph.D., showed that individuals with autism spectrum disorder (ASD) had different patterns of brain connectivity between areas involved in speech processing compared with their peers. A subsequent study found that in ASD, the mechanisms involved in processing speech are influenced by atypical attention patterns, possibly stemming from differences in how the cerebellum manages timing and predicts auditory events. His 2015 Emerging Research Grant was generously funded by Royal Arch Research Assistance.

Manoj Kumar, Ph.D., described a new tool for visualizing zinc ions in the brain. Changes to the amount of zinc ions at the synapses has been linked to neurological diseases including hearing disorders. Kumar also advanced understanding of the cortical mechanisms underlying disorders associated with maladaptive cortical plasticity after peripheral damage, such as tinnitus, hyperacusis, and difficulty hearing in noisy environments. Kumar’s 2022 Emerging Research Grant is generously funded by Royal Arch Research Assistance, and was renewed for a second year in 2023.

Pei-Ciao Tang, Ph.D., explored the potential of the stem cell-derived inner ear organoid system for studying early mammalian placode development, for future high-throughput drug screening and cell therapy.

Vijaya Prakash Krishnan Muthaiah, Ph.D., detailed a potential therapy for blast-induced hearing loss and tinnitus. By inhibiting a certain protein it may be possible to maintain the health and survival of hair cells following blast injuries. His 2019 Emerging Research Grant was generously funded by Royal Arch Research Assistance.

A. Catalina Vélez-Ortega, Ph.D., found that the activation of certain ion channels in the cochlea seems to be a protective mechanism, like wearing earplugs, minimizing exposure to sound. Her 2018 Emerging Research Grants was funded by Cochlear Americas.

Andy Groves, Ph.D., and Litao Tao, Ph.D., studied how key genes required for converting supporting cells to hair cells are shut off through a process known as epigenetic silencing, leading to how they could be turned back on to regenerate hearing.

Pierre Apostolides, Ph.D., detailed a mechanism of inhibition in the inferior colliculus, a region along the auditory pathway that is important for speech processing, that allows for a higher level of control and processing.

Finally, Lisa Goodrich, Ph.D., shared highlights of recent Hearing Restoration Project accomplishments, including demonstrating that a cocktail of three factors can promote conversion of nonsensory cells into hair cells in the mouse model.

Thanks to you, these and other HHF-funded scientists are continuing to discover life-changing breakthroughs to better prevent and treat hearing loss, tinnitus, and related conditions. We are grateful for your continued interest and generosity.

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