The Path to a Cure for Hearing Loss and Tinnitus

By Laura Friedman

On May 21, 2015, Hearing Health Foundation hosted its first live-video research briefing as part of our effort to provide regular updates on our research programs and progress. Through these briefings, our goal is for our attendees to obtain new information and understanding about hearing loss, prevention and research toward a cure.

During this inaugural research briefing, Dr. Peter Barr-Gillespie, Scientific Director, Hearing Restoration Project presented the Hearing Restoration Project (HRP). The HRP was founded in 2011 and is the first and only international research consortium focused on investigating hair cell regeneration as a cure for hearing loss and tinnitus. The overarching principle of the consortium is collaboration: open sharing of data and ideas. The HRP consortium consists of 14 of the top investigators in the audiological space, as well as a scientific director, Dr. Barr-Gillespie.

We wanted to share with you highlights from the presentation, which is available to watch with live captioning or to read with notes summarizing each slide. 

1. History of Hearing Health Foundation

   • Founded in 1958, established reputation for pioneering breakthroughs in hearing and balance research.

     • Early supporters of the revolutionary cochlear implant. Today, over 220,000 children and adults benefit.

     • Advocated for the passage of Universal Newborn Hearing Screening legislation in the 1990s. Today, 97% of newborns are tested for hearing loss at birth.

     • The Emerging Research Grants Program provides seed funding for researchers in hearing and balance science such as discoveries in hair cell regeneration, tinnitus, hyperacusis, and Ménière’s research. 

2. The Challenge

   • In the past century, the primary treatment for hearing loss has been hearing aids and cochlear implants. While these have been very successful treatments, they have limitations.

   • For this century, we have a number of different avenues for more effective therapy. 

     • Preventing the damage to the hair cells to preserve hearing. By generating greater awareness of the effects of hearing loss, we aim encourage people of all ages to protect their ears.

     • Gene therapy, targeting those who have lost hearing due to genetic disorders.

     • The majority of people who have lost hearing have done so through noise damage or aging, and may be candidates for hair cell regeneration/restoration.

3. HRP Consortium History & Model

   • One of the key facets of the HRP’s approach is that we use three different animal models for studying hair cell regeneration

     • Two of those models, the chick and the zebrafish, show robust hair cell regeneration.

       • f you damage the hair cells of a chick or a fish, within a short time—only a day or two for the fish, a few weeks for the chick—the hair cells come back; new hair cells are formed.

         • So, that's spectacular, because it tells us that animals are capable of regenerating hair cells.

     • y contrast, the mouse is our other experimental model. Like in the human, the mouse shows no hair cell regeneration after a few days following birth.

       • You can damage the hair cells in the mouse and as far as we can tell, nothing much happens in terms of restoring hair cells. So, if we can figure out how to regenerate hair cells in the mouse, then we will be able to regenerate hair cells in people.

4. HRP Strategic Research Plan

   • Our strategic plan consists of three separate phases. We have already made a lot of progress on Phase 1 and we have initiated Phase 2:

     • Phase 1 – Discovery research:  Compare the fish, chick, and mouse to discover pro- or anti-regeneration pathways and determine supporting cell fates.

     • Phase 2 – Pathway validation: Verify pathways using fish, chick, and mouse models and describe regeneration strategies.

     • Phase 3 – Develop therapies and treatment options: Identify drugs that trigger hair cell regeneration in the mouse model.

5. Progress To-Date

   • Progress on Phase 1: We've identified a variety of candidates for hair cell regeneration and the pathways that are necessary. 

     • We have too many, so we really are continuing to use bioinformatics methods to winnow down and determine which are most important.

     • We have definitively shown, at least in the mouse, the specialized supporting cells remain.

     • We know now what our target cells are for triggering hair cell regeneration. 

   • Phase 2 has begun, but we haven’t stopped Phase 1: 

     • We've got multiple approaches to try and see whether or not we can block regeneration in the fish and chick or stimulate regeneration in the mouse.

   • Phase 3 is in sight:

     • Experimental models from Phase 2 will be used to screen for drugs—using the mouse first

6. The Next Five Years

   • With your help, we can continue to quicken the pace towards a cure. Here’s our plan for the next five years: 

     • Phase 1 will continue: more candidate generation for Phase 2

     • Phase 2 (pathway verification) already initiated in zebrafish, mouse, chick (low throughput)

     • Phase 2 must be scaled up: many more genes, combinatorial approaches; cell lines for screening

     • Phase 3 (drug screening) requires the right screening model, which will come out of Phase 2.

The Future is Very Bright – But we need your support!

Hair cell regeneration is a plausible goal for eventual treatment of hearing and balance disorders. The question is not if we will regenerate hair cells in humans, but when.  However, we need your support to continue this vital research and find a cure! Please make your gift today.  

What Animals Can Tell Us About Humans

By Yishane Lee

Recent findings in mice by University at Buffalo scientists may one day help us better understand human hearing loss. Mice have an inner ear structure and auditory system organization similar to humans, and they also progressively lose their hearing as they age. As published in the Journal of the Acoustical Society of America in October 2014, the researchers found that mice process and understand their “ultrasonic vocalizations” (USVs), which the human ear cannot perceive, in the same way humans make sense of our own vocalizations.

Like humans (and birds), it appears that mice can distinguish a vocalization when just the beginning part is heard, versus when the end part is heard. This helps strengthen the usefulness of mice as good models for understanding human communication and hearing loss.

Dogs also have a language comprehension ability similar to humans. According to recent British study, dogs process speech in a similar way to humans: They listen to our words, not just our intonation.

According to the report, published in the journal Current Biology in November, dogs use different parts of the brain—both the left and right hemispheres—to process the verbal components of a familiar sentence and the emotion or intonation of the speaker. The study suggests that dogs pay attention to the verbal content of human speech and perceive it in a way that broadly parallels human perception. The reseachers concluded, “Dogs may share ancestral or convergent hemispheric specializations for processing the different functional communicative components of speech with human listeners.”

Learn about the amazing chick discovery and HHF’s path to curing hearing loss and tinnitus.

The Link Between Your Kidneys and Your Hearing

By Judy Huch, AuD and Laura Friedman

March is National Kidney Month and today, March 12th, is World Kidney Day. Why is this important? For years we have been aware of rare syndromes involving renal disorder and hearing loss, such as Alport, MYHIIA, Muckle-Wells, Brescheck, and Bartter syndromes.1 But in October 2010, a study done in Australia showed a link between chronic kidney disease (CKD) and hearing loss, which was published in the American Journal of Kidney Diseases.

This study examined the “medical records of 2,564 people aged 50 and over, 513 of whom had moderate chronic kidney disease. Some 54.4% of all the patients with chronic kidney disease had some degree of hearing loss, as compared to only 28.3% of those who had no kidney problems.” Even more interesting, 30% of the CKD patients had a severe hearing loss compared to just 10% in those patients without CKD.

So what is the correlation between the CKD and hearing loss? According to researchers, "The link can be explained by structural and functional similarities between tissues in the inner ear and in the kidney. Additionally, toxins that accumulate in kidney failure can damage nerves, including those in the inner ear." Also, some treatments for kidney ailments are ototoxic, meaning they cause hearing loss. 

In the U.S., there are 31 million adults living with kidney disease, 7.5 million of whom have moderate forms of CKD.  Based on the recent findings it is important that these patients be aware that their hearing is also at risk. If you have patients or know anyone with chronic kidney disorder, please urge them to have their hearing tested annually to monitor any changes to their hearing status.

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1Toriello, H. V., Reardon, W., & Gorlin, R. J. (2004). Hereditary hearing loss and its syndromes. (Second ed., pp. 267-289). New York, NY: Oxford University Press.

A portion of this post originally written by Judy Huch, AuD, Editor of Hearing Health @ Hearing Health & Technology Matters.Other content was contributed by Healthy Hearing, The American Speech-Language-Hearing Association, and Oregon's Deaf and Hard of Hearing Services.

Hearing Restoration Project (HRP) Special Research Update

By Peter G. Barr-Gillespie, PhD

We always seek ways to deepen the research collaboration between the consortium members. Since its creation more than three years ago, the HRP consortium has gathered twice each year for scientific meetings; these interactions have proven to produce meaningful research outcomes. The following is a recent example:

At the meeting held in Seattle last fall, 15 researchers convened to compare and discuss data from the past year, as well as to plan for the coming year’s projects. During the discussions, five of the investigators were surprised to find that they independently had the same observation, one that was so surprising that they each initially dismissed it as an experimental artifact. They had each separately found this result: in an adult mouse cochlea that had previously lost its hair cells due to damage from sound or drugs, weeks later, a few cells remaining in the cochlea began to display molecular markers related to hair cells.

These results may suggest that the supporting cells in the cochlea are more responsive to damage than we thought, and that they were trying to convert into new hair cells. The five different groups had the same observation using very different methods added considerable weight to the findings, and emphasize the value of the collaborative, data-sharing approach to science utilized by the HRP.

These observations were talked about among the 15 HRP investigators, and a new project was born to further investigate what were provisionally labeled “X-cells.” Given the flexibility of the HRP’s funding process, we were able to fast-track the proposal. The investigators wrote the proposal in a few weeks and vetted it with the rest of their HRP colleagues; the proposal was then evaluated and approved by the Scientific Advisory Board of the HRP and the project is now moving forward.

We hope to see exciting results from this project, which should establish whether these “X-cells” are real. If so, the HRP will determine how to push these cells further along their molecular differentiation pathway to become full-fledged hair cells, which might restore hearing in damaged ears. 

HHF understands the value of the consortium and has enabled the group to meet regularly for these important discussions. When the consortium members agree that an area of research deserves further exploration, a proposal is written and put forth for review and approval. Once approved, the fact that HHF can release the funds quickly helps to accelerate the pace of research.  

This helps us get closer to our goal of a cure!

Peter G. Barr-Gillespie, PhD

Director, Hearing Restoration Project

Advances in Brain Training

By Kathi Mestayer

Because the brain is an integral component of the hearing process, it sometimes needs help adjusting to new types of sound. The brain needs to fill in some of the blanks when hearing is impaired or when adjusting to a new hearing aid or cochlear implant. “Aural rehabilitation is so much more than speechreading [lipreading],” says Kathleen Cienkowski, Ph.D., an associate professor and the program director of audiology in the University of Connecticut’s Speech, Language, and Hearing Sciences Department. “It’s basically retraining the brain.” She adds, “Cochlear implants, hearing aids, and listening systems can do wonders, but no assistive device is as smart as your brain. Our brains know what we want— and don’t want—to hear; integrate the other senses; and interpret body language, tone, pacing, and context.” Getting used to new sounds is a big adjustment. That’s when aural or auditory rehabilitation comes in. Cienkowski, who also coordinates the Aural Rehabilitation Interest Group for the American Speech-Language- Hearing Association (ASHA), defines it as “improving the quality of life and communication for those with hearing loss.”

To read the full article please read Fall issue of Hearing Health Magazine by clicking here. 

Eating Sushi for Better Hearing Health

By Pallavi Bharadwaj

I recently became a pescatarian (mostly) and adore sushi. I am glad that after being a vegetarian all my life I finally added fish to my diet because according to a study published recently in the American Journal of Clinical Nutrition, women who eat fish regularly have a lower risk of developing hearing loss than those who rarely or never eat fish.

The authors of the study used data that were collected as part of the Nurses’ Health Study II, a prospective cohort study. On the basis of the data, they examined independent associations between consumption of fish and long-chain omega-3 polyunsaturated fatty acids (PUFAs) and self-reported hearing loss in 65,215 women who were followed from 1991 to 2009. Participants were asked to fill out questionnaires every two years.

The women who consumed fish at least twice a week were found to have a 20 percent lower risk of hearing loss versus those who consumed fish less often (less than once a month). This protective action was found irrespective of the type of fish consumed. A higher intake of omega-3s, particularly EPA (ecosapentaenoic acid) and DHA (docosahexaenoic acid), was also associated with a lower risk of hearing loss. However, no association was found for consumption of omega-6 fatty acids.

“Omega-3 antioxidants, polyunsaturated fatty acids, and vitamin C have been the focus of a growing body of evidence showing potential hearing benefits,” says Gordon Hughes, M.D., the program director for clinical trials at the National Institute on Deafness and Other Communication Disorders, which provided funding for the study.

Other studies had already established a link between eating fish—the omega-3s they contain in particular—and a lower risk of cardiac and cerebrovascular diseases. It is thought that a diet rich in these foods helps to maintain blood flow to the cochlea through similar mechanisms, thus providing oxygen and nutrients that the cochlea needs to function properly.

It's Reasonable to Continue Drinking Coffee

By Pallavi Bharadwaj

National Coffee Day was yesterday. A number of national fast food chains doled out free coffee to mark the day. But wait! There is more than one reason to celebrate this dark caffeinated drink.

New study findings have shown that higher caffeine intake is associated with a lower risk of tinnitus, although the underlying mechanism remains unknown. The study showed that intake of caffeine, in the form of coffee, tea, sodas, candy and chocolate, was on the contrary, associated with a lower risk of incident self-reported tinnitus.

Caffeine has long been thought to play a role in the development of tinnitus, but no pertinent clinical data are available. On the basis of data from the Nurses’ Health Study II, a team of researchers from Ontario, Canada and Massachusetts, USA, compared caffeine intake levels and the incidence of tinnitus. Study participants included 65,085 women in the survey, aged 30 to 44 years and who did not have tinnitus at baseline in 1991. Participants completed questionnaires about lifestyle and medical history every two years and food questionnaires every four years.

Information on self-reported tinnitus and date of onset was obtained from the 2009 questionnaire, with cases defined as those reporting experiencing symptoms “a few days/week” or “daily.” Multivariable adjusted hazard ratios (HRs) were calculated using Cox proportional hazards regression models.

“We can’t conclude that caffeine is a cure for tinnitus,” says the lead author, Dr. Jordan T. Glicksman. “But our results should provide some assurance to people who do drink caffeine that it’s reasonable to continue doing so.”

Sources:

• Glicksman JT, et al. A prospective study of caffeine intake and risk of incident tinnitus. The American Journal of Medicine 2014 Aug;127(8):739-43;

• New York Times August 13, 2014

• For more tinnitus resources, please visit ‘What is Tinnitus’ section on HHF’s website

ERG 2015 Announcement

By Pallavi Bharadwaj

We are excited to inform you of the opening of the application period for Hearing Health Foundation's 2015 Emerging Research Grants program. 

This program is designed only for the first year applicants, who are dedicated to explore new avenues for hearing and balance science. Please note that the current Hearing Health Foundation awardees, applying for a second year of funding, are no longer eligible. 

We encourage you to review our announcement and Policy on Emerging Research Grants, as several eligibility changes have gone into effect for this funding cycle. If you are eligible to apply for this program, please make note of the deadlines given below. 

For 1st year Applicants:

LOI deadline: October 25, 2014 by 5pm ET

Full Application opens: Early November, 2014

Full Application deadline: December 6, 2014 by 5pm ET
Then please review the instructions for submitting a LOI.

With any questions about this opportunity, please feel free to reach out to us at grants@hearinghealthfoundation.org . 

Thank you for your interest in this program and please do share this information with your interested colleagues as well. 

Emerging Research Grants for 2014 Announced

By Tara Guastella

HHF is proud to announce that 10 leading hearing scientists have been an awarded an Emerging Research Grant. It was an incredibly competitive funding cycle and it is a true honor for these investigators to have risen to the top and received this award.

Six grantees are first-year grant recipients and are studying areas such as noise-induced hearing loss, tinnitus, ototoxicity (hearing loss caused by certain drugs and medications), age-related hearing loss, and hearing aids.

Four previous grantees are receiving a second year of funding for their work. This group is researching such areas as central auditory processing disorder (CAPD), auditory physiology, cochlear implants, genetic hearing loss, and Usher syndrome.

One first-year grant recipient, whose work is funded by the continuing support of the General Grand Chapter Royal Arch Masons International, is aimed at developing better ways to assess auditory processing disorders. Here is an excerpt on his work:

Srikanta Mishra, Ph.D.

New Mexico State University

Medial Efferent Mechanisms in Auditory Processing Disorders

Many individuals experience listening difficulty in background noise despite clinically normal hearing and no obvious auditory pathology. This condition has often received a clinical label called auditory processing disorder (APD). However, the mechanisms and pathophysiology of APD are poorly understood. One mechanism thought to aid in listening-in-noise is the medial olivocochlear (MOC) inhibition— a part of the descending auditory system. The purpose of this translational project is to evaluate whether the functioning of the MOC system is altered in individuals with APD. The benefits of measuring MOC inhibition in individuals with APD are twofold: 1) it could be useful to better define APD and identify its potential mechanisms, and 2) it may elucidate the functional significance of MOC efferents in listening in complex environments. The potential role of the MOC system in APD pathophysiology, should it be confirmed, would be of significant clinical interest because current APD clinical test batteries lack mechanism-based physiologic tools.

Read more about the research all of the 2014 grant recipients are conducting.

The HRP's Andy Groves, Ph.D. and HHF Board member Nancy M. Williams to Speak at HLAA Convention

By Tara Guastella

If you are headed to Austin for the Annual Hearing Loss Association of America (HLAA) Convention at the end of June, make sure to stop by Andy Groves, Ph.D.’s workshop on Friday, June 27, at 1:30pm.

Andy Groves, Ph.D.

Baylor College of Medicine

Dr. Groves will be giving a presentation on the Hearing Restoration Project (HRP) and how the power of collaboration is expediting the road to a cure for hearing loss and tinnitus. Chickens, fish, and most non-mammals have a remarkable ability to naturally restore damaged inner ear hair cells (damage or death of these cells is what causes hearing loss). The HRP is working to identify how we can translate this process, known as hair cell regeneration, to humans to develop a biologic cure for hearing loss and tinnitus.

The HRP scientists are working collaboratively sharing ideas, data, and resources to shorten the timeline to a cure. During our last monthly conference call with the consortium, an HRP scientist was presenting initial data on a series of experiments he is conducting. After feedback from other consortium members, he will now approach the experiment in a more beneficial way with greater impact to the research process. This experience highlighted the power of many minds over one.

Hear more about the HRP and the exciting research advancements at Dr. Groves’s workshop on Friday. Materials and information on the HRP will be available for attendees so don’t forget to pick up more information while you’re there.

HHF Board member, Nancy M. Williams, pianist and hearing loss advocate, will also be presenting at the HLAA Convention. She will share her story of reclaiming the piano to help participants tap into their passions.

When Williams reclaimed her passion for the piano after a 25-year hiatus, she came to terms with her hearing loss—and pursuing her passion radiated out to other aspects of her life. Ms. Williams will share her story in the “Finding Your Calling... Despite a Hearing Loss" workshop on Saturday, June 28 at 8:45am.

Be sure to stop by both exciting sessions!