Suffering After Sacrifice

By Lauren McGrath

Every Veterans Day, Hearing Health Foundation (HHF) celebrates the brave individuals who have served and sacrificed to defend our country. We are grateful to our active military members and veterans for their courageous protection of American values and freedoms.

As we honor those who have served in the U.S. Armed Forces, we acknowledge a tragic and troubling health problem. An astounding number of veterans—60% of those returning from Iraq and Afghanistan—live with tinnitus and noise-induced hearing loss. In 2017, the Veterans Administration reported 1.79 million disability compensation recipients for tinnitus and 1.16 million compensation recipients for hearing loss, the number one and two disabilities, respectively. In an HHF video about hearing loss treatment, Retired Army Colonel John Dilliard, Chair-Elect of HHF’s Board of Directors, explains, “The noise from repeated gunfire and high-frequency, high-performance aircraft engines takes its toll on the human hearing mechanisms.” Col. Dillard lives with both tinnitus and hearing loss following 26 years of service.

John Dillard and fellow soldiers, Fort Irwin National Training Center, 1977.

Dr. Bruce Douglas, 93, remembers the moment his hearing became severely compromised while serving in the Navy during the Korean War. “On what was my 26th birthday, after pulling the trigger on the M1 rifle with no protection (none of us had any) multiple times, I was left with tendonitis in both knees—and worse, permanent, chronic tinnitus due to acoustic trauma. My hearing went downhill ever after, and every imaginable kind of sound and sensation has resulted from my tinnitus,” Douglas writes in the Fall 2018 issue of Hearing Health.

Hearing protection training must start as soon as one enters the military. But there is a misconception that hearing protection inhibits vital communication and mission readiness because hearing signs of danger is imperative to survival. “Soldiers want to be able to hear the snap of the twig and want to be able to be situationally. As a result, they are often resistant to wearing hearing protection,” Col. Dillard says.

Fortunately, sophisticated hearing protection technology does exist so that military personnel do not have to choose between protecting their ears or their lives. Examples include noise-attenuating helmets, which use ear cups to protect against hazardous sound, and Tactical Communication and Protective Systems, which protect against loud noises while amplifying soft ones.

The U.S. military continues to work toward safer hearing in the service. The U.S. Army has developed the Tactical Communication and Protective System (TCAPS), which are earbuds that dampen dangerous noises to safe levels using microphones and noise-canceling technology, while also providing amplification of softer sounds and two-way communication systems. An initiative by the U.S. Air Force called Total Exposure Health (TEH), meanwhile, focuses on overall health both on and off the job, will measure cumulative noise exposure over the course of 24 hours. These developments and others, which HHF applauds, are covered in greater detail in Hearing Heath’s Fall 2017 issue.

As greater preventative technology for our military becomes available, HHF remains dedicated to finding better treatments and cures for tinnitus and hearing loss to benefit the lives of millions of Americans, including veterans, a disproportionately affected group. We hope you will join us in remembering their sacrifices with gratitude and compassion.

Measuring Brain Signals Leads to Insights Into Mild Tinnitus

By Julia Campbell, Au.D., Ph.D.

Tinnitus, or the perception of sound where none is present, has been estimated to affect approximately 15 percent of adults. Unfortunately, there is no cure for tinnitus, nor is there an objective measure of the disorder, with professionals relying instead upon patient report.

There are several theories as to why tinnitus occurs, with one of the more prevalent hypotheses involving what is termed decreased inhibition. Neural inhibition is a normal function throughout the nervous system, and works in tandem with excitatory neural signals for accomplishing tasks ranging from motor output to the processing of sensory input. In sensory processing, such as hearing, both inhibitory and excitatory neural signals depend on external input.

For example, if an auditory signal cannot be relayed through the central auditory pathways due to cochlear damage resulting in hearing loss, both central excitation and inhibition may be reduced. This reduction in auditory-related inhibitory function may result in several changes in the central nervous system, including increased spontaneous neural firing, neural synchrony, and reorganization of cortical regions in the brain. Such changes, or plasticity, could possibly result in the perception of tinnitus, allowing signals that are normally suppressed to be perceived by the affected individual. Indeed, tinnitus has been reported in an estimated 30 percent of those with clinical hearing loss over the frequency range of 0.25 to 8 kilohertz (kHz), suggesting that cochlear damage and tinnitus may be interconnected.

However, many individuals with clinically normal hearing report tinnitus. Therefore, it is possible that in this specific population, inhibitory dysfunction may not underlie these phantom perceptions, or may arise from a different trigger other than hearing loss.

One measure of central inhibition is sensory gating. Sensory gating involves filtering out signals that are repetitive and therefore unimportant for conscious perception. This automatic process can be measured through electrical responses in the brain, termed cortical auditory evoked potentials (CAEPs). CAEPs are recorded via electroencephalography (EEG) using noninvasive sensors to record electrical activity from the brain at the level of the scalp.

Cortical auditory evoked potentials (CAEPs) are recorded via electroencephalography (EEG) using noninvasive sensors to record electrical activity from the brain.

In healthy gating function, it is expected that the CAEP response to an initial auditory signal will be larger in amplitude when compared with a secondary CAEP response elicited by the same auditory signal. This illustrates the inhibition of repetitive information by the central nervous system. If inhibitory processes are dysfunctional, CAEP responses are similar in amplitude, reflecting decreased inhibition and the reduced filtering of incoming auditory information.

Due to the hypothesis that atypical inhibition may play a role in tinnitus, we conducted a study to evaluate inhibitory function in adults with normal hearing, with and without mild tinnitus, using sensory gating measures. To our knowledge, sensory gating had not been used to investigate central inhibition in individuals with tinnitus. We also evaluated extended high-frequency auditory sensitivity in participants at 10, 12.5, and 16 kHz—which are frequencies not included in the usual clinical evaluation—to determine if participants with mild tinnitus showed hearing loss in these regions.

Tinnitus severity was measured subjectively using the Tinnitus Handicap Index. This score was correlated with measures of gating function to determine if tinnitus severity may be worse with decreased inhibition.

Our results, published in Audiology Research on Oct. 2, 2018, showed that gating function was impaired in adults with typical hearing and mild tinnitus, and that decreased gating was significantly correlated with tinnitus severity. In addition, those with tinnitus did not show significantly different extended high-frequency thresholds in comparison to the participants without tinnitus, but it was found that better hearing in this frequency range related to worse tinnitus severity.

This result conflicts with the theory that hearing loss may trigger tinnitus, at least in adults with typical hearing, and may indicate that these individuals possess heightened auditory awareness, although this hypothesis should be directly tested.

Overall, it appears that central inhibition is atypical in adults with typical hearing and tinnitus, and that this is not related to hearing loss as measured in clinically or non-clinically tested frequency regions. The cause of decreased inhibition in this population remains unknown, but genetic factors may play a role. We are currently investigating the use of sensory gating as an objective clinical measure of tinnitus, particularly in adults with hearing loss, as well as the networks in the brain that may underlie dysfunctional gating processes.

2016 Emerging Research Grants scientist Julia Campbell, Au.D., Ph.D., CCC-A, F-AAA, received the Les Paul Foundation Award for Tinnitus Research. She is an assistant professor in communication sciences and disorders in the Central Sensory Processes Laboratory at the University of Texas at Austin.

You can empower work toward better treatments and cures for hearing loss and tinnitus. If you are able, please make a contribution today.

A Muffled Life

By Jim Lynch

A Tricycle Mishap

For a 5-year-old a tricycle is a mini Lamborghini. Whether this particular model belonged to my family or our next-door neighbor has long since faded in memory, but what made it especially attractive was fashioned to its handlebar: a rubber squeeze-bulb and silver metal horn. Jackie Gilroy and I took turns riding it between our houses for hours during the summer before I was scheduled to enter first grade. We were particularly fascinated by the sound of the horn, a noise we could make louder by using two hands to squeeze air into the metal chamber.

I can’t remember which of us made the suggestion, but one day we discovered that if we placed our ears next to the horn, the sound was louder still. Therefore, in the impulsive and thoughtless manner of children, we took turns blaring that explosive clangor into each other’s ears at point blank range for a good part of the afternoon. We laughed at our discovery and discovered that the effect lasted even longer, with ringing in our ears.

When I woke the next morning and came downstairs, my mother was at the stove finishing scrambled eggs for my breakfast. As she put my plate before me, I saw her lips moving, but I heard nothing. I put my hands to my ears and began to cry as she tried without success to converse with me. Not only couldn’t I hear her, but I also couldn’t hear my own words, or even the sound of my crying. Overnight, I had become completely deaf.

Facing It

Over the next few days, some muted hearing gradually returned. After I informed her of my squeeze-bulb horn activity, she made an appointment for us with an audiologist. After explaining to him what I had done, and undergoing what passed for extensive testing in midcentury (I remember a series of tuning forks and having to turn my head at various angles and respond to his whispered questions), he informed her that I had permanently damaged the nerve endings at the higher frequency range of hearing in both ears. I remember him telling her that what had happened to me was akin to a soldier’s hearing when a grenade goes off in close proximity. While I didn’t suffer physical injury, the hearing loss was the same.

Even if there were hearing aids available during that era, two things became readily clear: my family would not have been in a financial position to afford them, and, given the type of hearing loss I had sustained, they wouldn’t have helped. Whatever the quality or degree of auricular attenuation I had sustained, it was permanent, and would last for the rest of my life. At five years of age, however, I was simply happy to have regained a measure of hearing. Whatever consequences suffered by Jackie Gilroy are lost to memory.

At that point in my young life, I had little trouble understanding my parents, siblings and friends who were in close proximity. They sometimes had to get my attention if my head were turned (my brothers would often yell, “Hey Beltone!”), but face-to-face conversation was possible. Even so, my parents decided to postpone enrolling me in first grade that September, with the hope that things might somehow improve before I would need to function in a classroom environment.

Starting first grade a year later, I began a long auditory adjustment that paralleled any and all social interaction. My hearing difficulty often appeared to teachers and fellow students as indifference, disrespect or stupidity. High-frequency loss also made it impossible to hear the syllables of some words, and therefore difficult to pronounce them as well.

The “ed” on the past tense of “ask,” for example completely disappeared. Sibilant syllables vanished from spoken words, and the susurration of whispers made them indecipherable. Embarrassment and mockery are stern but effective teachers, however, and they provided remarkable motivation for a trial-and-error approach to the demands of a wider world.

And Faking It

I soon ascertained that there were many compensatory methods to bring to bear on my degraded hearing. I quickly learned, for example, that the first hint of what others were saying lay in their facial expressions. A frown, scowl or smile provided a starting point for what was to come.

Tone of voice was also a powerful indicator. A flat, staccato grouping of words coupled with a stern expression were causes for apprehension, while a soft, lilting tone combined with an open face often indicated harmony or agreement. If a speaker’s inflection turned up at the end of his sentence, he was likely posing a question.

I further adapted to a system of filling in the gaps when some of the words in a sentence went unheard because of distance, volume or pronunciation. “In what____ was the _______Armada ________ by Great _______?” From the back of the class, such an obvious question (upward inflection at end of sentence) could be understood in sufficient time by a student with hearing loss who had read the assigned history chapter. Those strategies worked with a modicum of success in a classroom where one person spoke at a time. In a noisy environment, however, sounds grew more remote and understanding more problematic.

When as an adult I had an extensive and more sophisticated evaluation done by an audiologist, I discovered that my hearing levels were 70% of normal in the left ear, and 72% in the right. Because of years of adapted strategies, however, my range of understanding registered in the low 90% level for both ears in a quiet, isolated environment.

Lingering Difficulties and Treatment at Last

Nevertheless, song lyrics and movie dialogue continued to pose problems. Because the usual strategies often failed in such circumstances, I often relied on imagination to provide meaning. With resourceful creativity, I used the melody of songs, and the tone of cinematic dialogue, as well as body language of the actors, to provide sufficient clues to the overall context of songs and movies. I sometimes think that my imagination provided better lyrics and dialogue than the lyricist or scriptwriter.

Not until 2005 did technology become available to augment my adaptive methodology. The devices I now use improve my hearing marginally, but I still rely on a lifetime of learned maneuvers to interact with others. Although the sounds of previously difficult sibilant syllables became somewhat crisper, other problems remain or were created.

A moderate wind sounds like a typhoon when it blows over the device’s microphone. In addition, ambient noise levels can still totally negate any level of discernment. At a social gathering such as a wedding reception, for example, the murmur and babble of guests make understanding people directly across a table hit-and-miss. When the band or DJ begins, I must cease conversation altogether, except to respond to the person to my immediate right or left, and then with considerable difficulty.

In the classroom, my disadvantage created a different approach to interaction with students. Because I was fortunate to teach in an atmosphere of deference and tranquility, the majority of conversations with students proceeded nicely. Sometimes, however, soft-spoken or rapid-speaking students, or those in the rear of the class could pose problems. If a request for a repeated question or comment failed to generate clarity, years of learned compensatory techniques usually facilitated sufficient comprehension.

It Made Me a Better Teacher

In retrospect, I suspect that my auditory deficit, and the changes it wrought, made me a better teacher than I would have been with typical hearing. Because I had to utilize alternate methods and techniques (with a visible keenness of focus) to interact with students, my interest in their opinions and evaluations must have conveyed an unusual intensity. As I strained to comprehend their questions, concerns and comments, my physical demeanor emphatically registered the genuine value I placed on understanding their questions and comments in class discussions.

While a reduction in the ability to hear does not rise to the level of a significant physical disability, it changes the manner in which one must approach life. Such changes, although onerous, can also foster unforeseen advantages. My career as an educator was predicated on an adaptive approach to classroom procedure and management. Without a youthful hearing injury, I may not have gravitated toward teaching at all, or have enjoyed four decades of participation in that noble profession.

Jim Lynch was a high school English teacher for nearly four decades in the Wilkes-Barre, Pennsylvania area, as well as an adjunct English instructor at area universities and a community college. In retirement, he resides in Fleetwood, Pennsylvania with his wife of 51 years and two cats.

Sudden Hearing Loss Is a Medical Emergency

By Donna Rohwer

Mondays are always bad, right? I awoke deaf in my left ear—completely deaf. I asked my husband if he thought it was anything to worry about and he said, “Not yet.” I thought the same and appreciated the confirmation. We didn’t know then that sudden hearing loss is a medical emergency.

Sudden Sensorineural Hearing Loss (SSHL)

Damage to the inner ear, the cochlea, or related nerve pathways cause SSHL. A loss of 30 decibels or more in three consecutive frequencies in one or both ears within several days is considered SSHL. Immediate treatment can make partial or total recovery more likely. Unfortunately, many medical professionals— from emergency room to waiting room—don’t recognize SSHL or know how to treat it. As a result, many patients lose the opportunity for recovery because they don’t get the right treatment within the critical time. In my case, I received treatment within a week—it wasn’t optimal, but better than many. I had no significant recovery.  

SSHL Is LOUD, Isolating, and Devastating

The shocking thing to SSHL patients is how LOUD everything becomes. Sounds distort and blend together, sound direction is lost, and every sound seems magnified. The tinnitus is sudden and loud, with whooshing, popping, and other sounds. The tinnitus often worsens with activity or background noise, and goes long into the night. Some people don’t feel well, see well, sleep well, or balance well. SSHL strains relationships and many people simply stop participating in activities. I felt as if I had lost my life.  

SSHL Can Be Life-Threatening

I consoled myself at first that my condition wasn’t life-threatening. Within weeks, however, I no longer wanted to go on living. I later learned that many people respond this way. Physicians recognize the psychological impact when someone loses a limb. Losing the sense of hearing, suddenly, is not dissimilar. I didn’t know how to live with SSHL, or where to turn for support. I felt abandoned until I received the mental health support I urgently needed.

Alone at the Table

I have slowly reclaimed my life through the support of family, friends, and several Facebook groups. I also have used a cognitive therapy course for tinnitus, antidepressants (briefly), and months of working through the process. But there are still moments. My passion is recreational poker. I recently played with a mixed group, some with typical hearing, some with hearing loss. The hearing people were talking, but the background noise kept me from understanding them, and I don’t know ASL. I felt alone at the table—caught somewhere between the hearing world and the deaf world.

What Do We, as SSHL Patients, Want?

We want non-ENT medical professionals to learn about SSHL and treat it as a medical emergency. We want ENT doctors to recognize the psychological aspects of SSHL and refer us to appropriate resources. We want hearing loss advocates to see that SSHL has unique challenges different from other kinds of hearing loss. Lastly, we want a cure.

You can empower work toward better treatments and cures for hearing loss and tinnitus. If you are able, please make a contribution today.

The Bridge Between Two Worlds

By Vicky Chan

Disability rights attorney Jared Allebest was born with a bilateral profound hearing loss. He was diagnosed at age 1 and fitted for hearing aids a year later. Today, Jared uses both hearing aids and ASL to communicate.

The son of a lawyer, Jared was determined to follow in his father’s footsteps and his hearing loss never deterred him. Throughout his education, he remained inspired by his favorite elementary school teacher, Ms. Marquardt, who taught him one of the most invaluable lessons: Having a hearing loss isn’t a barrier to success. “[Hearing loss] has affected my outlook to fight harder and to push myself to accomplish the things that I want to do in my life,” Jared explains.

After his graduation from Thomas Jefferson School of Law in 2009, Jared founded a law firm that advocates for people with hearing loss and speaking disabilities. The firm focuses on empowering their clients through education, advocacy, and lobbying. He works with clients with both typical hearing and hearing loss and takes on cases relating to disability rights or discrimination, as well as employment, marriage/divorce, and criminal law.

Jared admits that he faces auditory challenges in his profession. During trials, he has to be exceptionally attentive to all parties. He also receives assistance from an ASL interpreter in the courtroom so he doesn’t miss anything being said.

Despite some difficulty, Jared believes that his hearing loss is an advantage. His clients are more comfortable with him because they know he can empathize with them. People listen carefully when he speaks about issues concerning hearing loss. “By fighting for the rights of those who live with hearing loss, I am advocating for myself as well. I think of myself as the bridge between two worlds,” Jared says.

Jared’s strong reputation as a dedicated lawyer stems from his sincerity and passion for helping others with legal issues that are deeply personal to him. The most rewarding part of his profession is knowing that his clients are satisfied with his commitment.

Jared’s advocacy for the hearing loss community outside goes beyond the courtroom. He is the former chairman of Loop Utah—an advocacy group dedicated to educating people in Utah about the benefits of loop technology. He currently serves as a community representative on the Advisory Council to the Utah Division of Services to the Deaf and Hard of Hearing (USDB Advisory Council).

Of course, Jared knows he can’t be an advocate for all people with hearing loss, as much as he would like to be. He can’t be the connection between the legal world and the hearing loss world for everyone. Jared maintains that the most important part of living with hearing loss is effective self-advocacy. “Being assertive about your needs will help you to hear better, be more productive, and be happier.”

Jared lives and practices law in Utah. He is a participant in HHF’s Faces of Hearing Loss campaign.

Eight Pairs of Earplugs in Four Noisy Settings: My Hearing Protection Experiment

By Kayleen Ring

Before my 2018 summer internship at Hearing Health Foundation (HHF) in New York City, I underestimated the importance of protecting my ears, often leaving myself at risk for damage from noise at concerts, sporting events, and other loud places. I took my typical hearing for granted until learning that hearing loss is largely caused by noise exposure and can negatively impact the brain function of young adults, even in its mildest forms. But I was also encouraged to discover noise-induced hearing loss (NIHL) is preventable. Earplugs in particular are a convenient, low-cost tool for hearing preservation.

To improve my own hearing health and to create awareness about NIHL, I experimented with different types of earplugs in various loud settings. Expecting no more than a handful of foam options, I was excited to learn what an assortment of earplugs is available—each with different shapes, sizes, and features. Previously, my earplug experience had been limited to basic foam pairs to drown out my college roommates’ snoring!

I evaluated each personal earplug use experience with a 1 to 10 rating—10 being highest—for effectiveness, comfort, and ease of use. The Noise Reduction Rating (NRR) metric indicates how much noise is blocked out by the pair of earplugs.

Setting: Concerts

Just one loud concert (decibel levels up to 120 dB) can cause permanent damage to your ears. I tested earplugs at two musical events.

1. Eargasm High Fidelity Ear Plugs

• NRR: 16 dB

• Effectiveness: 10

• Comfort: 10

• Ease of Use: 10

At first, I worried wearing earplugs at a performance by one of my favorite artists would negatively affect my concert experience, but this pair allowed me to hear and enjoy the music perfectly at a reduced volume. They were so comfortable I forgot they were in my ears! They were easy to remove using the pull tab and I  also liked the carrying case they come in, because it fits in my small bag and keeps the earplugs hygienic for reuse.

2. Moldex Pocket Pak Squeeze

• NRR: 27 dB

• Effectiveness: 8

• Comfort: 9

• Ease of Use: 9

The triple-flange design, neck cord, and carrying case provided a secure earplug experience at an even louder concert where sound levels spiked to 120 dB. Unprotected exposure to noise at this level, which is equivalent to that of ambulance sirens or thunderclaps, can damage hearing in seconds. Fortunately, the ridged edges on the earplugs I used made inserting them far easier and faster than foam earplugs that need to be shaped prior to use.

Setting: Group Fitness

At a popular group fitness class, I recorded sound decibel levels and the results showed extremely loud and dangerous levels of noise. The average was 91 dB and the max was 119 dB over the one-hour class period. For a healthier workout, I wore earplugs.

3. Mack’s Blackout Foam Earplugs

• NRR: 32 dB

• Effectiveness: 9

• Comfort: 10

• Ease of Use: 9

These were excellent because I was able to hear the music and the trainers’ instructions, just at a lower volume. Less distracted by the loud music than usual, I was able to focus more carefully on my workout and form. They fit snugly and stayed in place over the course of the 60-minute, high-intensity session.

4. EarPeace “HD” High Fidelity Earplugs

• NRR: 19 dB

• Effectiveness: 10

• Comfort: 10

• Ease of Use: 8

I was particularly impressed that this pair included three set of filters offering different levels of protection. I used the highest decibel filter, 19 dB, and found the class music was still clear and enjoyable. My only challenge was properly inserting the very small filters.

Setting: Restaurants

When I didn’t intern at HHF this summer, I worked at a restaurant on Long Island, New York, that was always busy, sometimes bursting with chatty customers waiting three hours for service. Beyond the crowds, the restaurant had live musical performances that amplified an already loud environment. This is dangerous for workers and patrons alike. Here, the earplugs I wore still allowed me to hear clearly and hold a conversation.

5. Etymotic ER20XS High-Fidelity Earplugs (NRR: 13 dB)

• NRR: 13 dB

• Effectiveness: 8

• Comfort: 8

• Ease of Use: 9

The Etymotic earplugs had the positive qualities of the typical high-fidelity earplugs and included three interchangeable eartips, a hygenic carrying case, and a neck cord, providing a secure and effective earplug experience.

6. EarPeace “S”High Fidelity Earplugs

• NRR: 19 dB

• Overall Effectiveness: 10

• Comfort: 10

• Ease of Use: 10

This pair was great. They reduced the noise perfectly so it was at a comfortable yet still audible volume. The dual-flange design and soft silicone material made the earplugs fit well, were comfortable and easy to use.

Setting: New York City Subway

Decibel levels on the subway platforms trains are extremely high and can cause hearing damage, especially for frequent riders and employees. For my tests, I sat inside the 34th St-Penn Station 1/2/3 subway station across the street from the HHF office, where I was greeted by screeching trains, talkative tourists, and a steel drums player.

7. Moldex Sparkplugs

• NRR: 33 dB

• Overall Effectiveness: 9

• Comfort: 10

• Ease of Use: 9

The Sparkplugs blocked out noise while allowing me to hear conversations and train announcements. They were easy to mold into my ears, allowing for optimal noise reduction. The pattern on the earplugs is colorful and fun, making them appealing for children, and easily locatable in your bag.

8. Alpine Plug & Go

• NRR: 30 dB

• Overall Effectiveness: 8

• Comfort: 8

• Ease of Use: 8

These foam earplugs reduced volume but the noise was muffled. Consequently, these would be a great option for more sedentary activities, like sleeping and flying, where you are aiming to block out all noise. The foam was comfortable and fit snugly in my ears, but was challenging to mold.

The reviews and ratings here are based on my individual experiences and are not intended to encourage or discourage anyone’s use of specific earplugs. High ratings are not product endorsements. As someone newly informed about the dangers of noise, it is my hope my summer intern experiment for HHF will raise awareness and inspire others to investigate hearing protection that best meets their needs.

Kayleen Ring is a former marketing and communications intern at HHF. She studies marketing in the honors program at Providence College in Rhode Island.

The Happiest Baby—With Noise-Induced Hearing Loss

By Nadine Dehgan

Nothing in my life compared to giving birth and being able to hold my heart in my arms. As most sleep-deprived new parents will attest, there also is nothing quite like the helplessness you feel when this tiny person whom you love more than anything won’t settle and continuously cries (after being fed, changed, swaddled, and is fever-free).

Before my oldest daughter was born I thought I was well-equipped to be a parent. I had always been around children, was the second oldest of six children, became an aunt at 19, had a strict  pediatrician, took my parenting class seriously—and read “The Happiest Baby on the Block,” a best-selling book by Harvey Karp, M.D., recommended to me by other new parents.

Nine years later, it has been brought to my attention Karp’s ardently recommended action of “shh-ing” my daughters is extremely damaging to an infant, or any human. He advises the “shh-ing” sound needed to activate a crying baby’s calming reflex is a rough, rumbly whoosh noise that is as loud as your infant’s crying. This is at least 115 decibels (dB), according to Oregon pediatric audiologists Heather Durham, Au.D., and Shelby Atwill, Au.D. Alarmingly, sounds over 80 dB for an extended period of time are damaging and anything greater than 100 dB for even a few minutes can cause permanent noise-induced hearing loss (NIHL).

NIHL is an epidemic for American children—one in five are estimated to have significant hearing loss before the age of 20. I wonder how many children suffer from NIHL as a result of well-intentioned parents who relied on this harmful advice.

I remember reading I could put my daughters at ease by putting my mouth close to their ears and making a strong “shhhhhhhh” noise. The sound of someone’s forceful “shhhh” directly in your ear can actually be painful. (Please do not try it!) Babies have super hearing—the best hearing humans will have in their lives is when they are first born. I shudder to think how loudly I was “shh-ing” my daughters to sleep. The louder they cried, the louder I “shh-ed,” thinking I needed to do more to soothe them as I had learned.

A new grandparent and supporter of Hearing Health Foundation (HHF) recently alerted me to this danger, and after testing the decibels of my so-called soothing “shhh” sounds, I immediately had a pit in my stomach because indeed the noise is loud—dangerously loud. I had “shhh-ed” my daughters for countless nights and naps. White noise machines (usually in a stuffed animal) placed right near a baby’s head can be equally dangerous.

Like sun exposure, loud noise exposure has a cumulative effect; it could be that “inevitable” age-related hearing loss is merely the result of a lifetime of living in our noisy environments with unprotected hearing. Parents with newborns who are difficult to calm down need another, less risky option for inducing sleep, one without lifelong consequences.  

The Hearing Restoration Project: Update on the Seattle Plan and More

By Peter G. Barr-Gillespie, Ph.D.

Hearing Health Foundation launched the Hearing Restoration Project (HRP) to understand how to regenerate inner ear sensory cells in humans to restore hearing. These sensory hair cells detect and turn sound waves into electrical impulses that are sent to the brain for decoding. Once hair cells are damaged or die, hearing is impaired, but in most species, such as birds and fish, hair cells spontaneously regrow and hearing is restored.

The overarching principle of the HRP consortium is cross-discipline collaboration: open sharing of data and ideas. By having almost immediate access to one another’s data, HRP scientists are able to perform follow-up experiments much faster, rather than having to wait years until data is published.

Regenerated hair cells from chicken auditory organs, with the cell body, nucleus and hair bundle labeled with various colored markers. Image courtesy of Jennifer Stone, Ph.D.

You may remember that two years ago, we changed how we develop our projects. We decided together on a group of four projects—the “Seattle Plan”—that are the most fundamental to the consortium’s progress. These projects, which grew out of previous HRP projects, have now been funded for two years, and considerable progress has been made. We have also funded several other projects that have bubbled up out of new observations and capabilities, and they have added considerably to our knowledge base. With this in mind, I am pleased to share with you the latest updates for our 2018–19 projects.

SEATTLE PLAN PROJECTS

Transcriptome changes in single chick cells
Stefan Heller, Ph.D.

• Found that all “tall” hair cells are exclusively regenerated mitotically in this animal model.

• Compiled evidence for different supporting cell subtypes.

• Obtained good quality single cell RNA sequencing (scRNA-seq) data and are in the process of evolving an analysis strategy for the baseline cell types (control group). Identified about 50 novel marker genes for hair cells, supporting cells, and homogene cells, including subgroups.

• Developed a strategy to finish all scRNA-seq using a novel peeling technique and latest generation library construction methods.

•  Established two methods for multi-color in situ hybridization (PLISH, proximity ligation in situ hybridization) and SGA (sequential genomic analysis) for spatial and temporal mRNA expression validation.
  
  

Epigenetics of the mouse inner ear
Michael Lovett, Ph.D., David Raible, Ph.D., Neil Segil, Ph,D., Jennifer Stone, Ph.D.

• Completed epigenetic, chromatin structure, and RNA-seq datasets for FACS-purified cochlear hair cells and supporting cells from postnatal day 1 and postnatal day 6 mice, and provision of these data sets to the gEAR (gene Expression Analysis Resource portal) for mounting on their webpage through EpiViz for access by the HRP consortium.

• Established a webpage (EarCode) so that HRP consortium members can access the current data directly through a University of California, Santa Cruz, genome browser.

• Discovered maintenance of the transcriptionally silent state of the hair cell gene regulatory network in perinatal supporting cells is dependent on a combination of H3K27me3 and active H3k27-deacetylation, and that during transdifferentiation, these epigenetic marks are modified to an active state.

Mouse functional testing
John Brigande, Ph.D.

• Defined in vitro and in vivo model systems to interrogate genome editing efficacy using CRISPR/Cas9.
  
  

Implementing the gEAR for data sharing within the HRP
Ronna Hertzano, M.D., Ph.D.

• Added scRNA-seq workbench for easy sharing and viewing of scRNA-seq data. Such data, which are now driving the field forward, have been particularly difficult to share

• Created additional public datasets to improve data sharing.

• Completely rewrote the gEAR backbone to be updated to the latest technologies, allowing the portal to now to handle a much larger number of datasets and users.

• Performed hands-on gEAR workshops at the Association for Research in Otolaryngology and the Gordon Research Conference, increasing the number of users with accounts to greater than 300.

Single Cell RNA-seq of homeostatic neuromasts
Tatjana Piotrowski, Ph.D.

• Optimized protocols for fluorescent-activated cell sorting and scRNA-seq; obtained high quality scRNA-seq transcriptome results from 1,400 neuromast cells; clustered all cells into seven groups; and performed analyses to align the cells along developmental time, providing a temporal readout of gene expressions during hair cell development.
  
  

OTHER PROJECTS

Integrated systems biology of hearing restoration
Seth Ament, Ph.D.

• Discovered 29 novel risk loci for age-related hearing difficulty through new analyses of genome-wide association studies of multiple hearing-related traits in the U.K. Biobank (comprising 330,000 people), and predicted the causal genes and variants at these loci through integration with transcriptomics and epigenomics data from HRP consortium members.

• Generated scRNA-seq of 9,472 cells in the neonatal mouse cochlea and utricle (postnatal days 2 and 7).

• Conducted systems biology analyses that integrate multiple HRP datasets to characterize gene regulatory networks and predict driver genes associated with the development and regeneration of hair cells. These analyses utilize scRNA-seq of sensory epithelial cells in mouse, chicken, and zebrafish hearing and vestibular organs, as well as epigenomic data (ATAC-seq) from hair cells, support cells, and non-epithelial cells in the mouse cochlea.

Comparison of three reprogramming cocktails
Andy Groves, Ph.D.

• Created and validated transgenic mouse lines expressing three different combinations of reprogramming transcription factors.

• Demonstrated these lines can produce new hair cell–like cells in the undamaged and damaged cochlea of the immature mouse.

• Compiled preliminary data showing Atoh1 and Gfi1 genes can create ectopic hair cells in the adult mouse cochlea.

Signaling molecules controlling avian auditory hair cell regeneration
Jennifer Stone, Ph.D.

• Identified four molecular pathways (FGF, BMP, VEGF, and Wnt) that control hair cell regeneration in the bird auditory organ. These pathways were identified in Phase I (gene discovery) as being transcriptionally dynamic in birds, fish, and mice during regeneration, which indicated they may be universal regulators of hair cell regeneration.

• Determined that the Notch signaling pathway (a powerful inhibitor of stem cells) also blocks supporting cell division in the chicken auditory organ after damage. This discovery shows that Notch is a negative regulator of regeneration, conserved in birds, fish, and mice.

• Identified signaling molecules in birds that are correlated with either mitotic or non-mitotic modes of hair cell regeneration, and are now exploring how these signaling molecules interact to determine which mode of regeneration occurs. Since mammals only exhibit non-mitotic regeneration, we are particularly interested in determining how this mode is controlled.
  
  

UP NEXT

We look forward to our annual meeting, which will be held in Seattle in November. There we will discuss and integrate these data to develop our plans for our 2019–20 projects.

As always we are very grateful for the donations we receive to fund this groundbreaking research to find better treatments for hearing loss and related conditions. Every dollar counts, and we sincerely thank our supporters.

HRP scientific director Peter G. Barr-Gillespie, Ph.D., is a professor of otolaryngology at the Oregon Hearing Research Center, a senior scientist at the Vollum Institute, and the interim senior vice president for research, all at Oregon Health & Science University. For more, see hhf.org/hrp.

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