A study debunks how hearing works

How We Thought Hearing Works

The way we hear is made up of a variety of mechanisms. Researchers from Linköping University explain these mechanisms in a SciTechDaily article. We’ve previously believed that those mechanisms were not so interconnected but rather more unique, and separate. For example, we’ve believed hearing to consist of sensory cells in the ear, with each cell having its own unique “optimal frequency.” What this means is that each sensory cell was said to have a different number of sound waves per second (frequency). Those sound waves or frequencies then prompt a reaction from the hair cell in the ear. While there are still separate mechanisms that help us hear, certain processes may be more interconnected than once believed.
Another widely held belief of hearing is that different parts of the tiny bone shaped structure of our ear, the cochlea, had similar functions. However, the  researchers behind this study discovered what we’ve believed for years might not actually be the case. After all, more and more research has been coming out on new information regarding the cochlea.

Read more: Researchers prove accessibility of the cochlea

The Study

Researchers set out to fill a gap that hasn’t yet been widely studied. Not much was known on how regions in the cochlea that encode sounds of low frequency worked. Researchers used the cochlea of guinea pigs with similar hearing capabilities, particularly in lower frequencies to humans. They used pure tone stimuli that only consisted of one frequency, and studied how responses were carried out. However, they explain that even though only one frequency was used, sounds naturally produce different frequencies. They discuss in depth how responses to this frequency can be changed by the auditory neurons that exist from the brain-stem to the cortex.

Findings

The findings from this study are remarkable. They show there are actually numerous cells within the inner ear that react to low frequency sounds all at once. For frequencies of less than 1,000 Hz, many cells are reacting together as opposed to separately as previously believed. Sounds in the low frequency category include vowel sounds of verbal speech, middle C on the piano, etc.

[The findings] show there are actually numerous cells within the inner ear that react to low frequency sounds all at once.

What This Means for the Future

These incredible findings have the potential to advance the field of hearing loss and hearing care. More specifically, researchers believe this could be a major headway into improving the design and function of cochlear implants. Currently cochlear implants are designed based off what was previously believed: that each cell has its own frequencies. Therefore, cochlear implants are structured for each individual electrode to stimulate the nerve at specific frequencies.
Based on the findings, researchers suggest implementing a new design. Anders Fridberger, professor from Linköping University told SciTechDaily, “The design of current cochlear implants is based on the assumption that each electrode should only give nerve stimulation at certain frequencies, in a way that tries to copy what was believed about the function of our hearing system. We suggest that changing the stimulation method at low frequencies will be more similar to the natural stimulation, and the hearing experience of the user should in this way be improved.”

Hearing loss and autism spectrum disorder

A collaborative study by the Medical University of South Carolina (MUSC) has found a link between hearing loss and autism spectrum disorder (ASD). Individuals who are on the autistic spectrum usually have an increased sensitivity to sounds. Researchers have been looking into the explanation of why this is occurring. Previous studies looked at neural pathways in the brain to see if there was a connection between ASD and hearing sensitivity. Up until now, they hadn’t found much of a potential link.

Hurdle

Prior to discovering a link between hearing loss and autism spectrum disorder, ASD patients were found to have hearing loss. However, hearing loss in ASD patients leads to an increased, over-stimulation of the senses. Sometimes this intense input of sound can be uncomfortable and overwhelming. How could this hearing loss end up causing an over amplification of sounds?

An interesting, proposed phenomenon, called central gain, is an adaptive response due to decreased auditory input. When the auditory stimulation is lowered, this theory suggests that the body increases neuronal gain. This neuronal gain usually results in excessive sound stimulation that can be both painful and unpleasant.

Hainan Lang, M.D., Ph.D, professor of Department of Pathology and Laboratory Medicine, wanted to find out if this central gain could be causing the brain to respond incorrectly in ASD individuals. He approached this by stating, “We didn’t have a clinically relevant model to directly test this important fundamental question.”

Read more: How to support a child with ASD and hearing loss

Collaboration

This study is powerful as it was a collaboration between the Department of Neuroscience, the Department of Pathology and Laboratory Medicine, and the Hearing Research Program at MUSC. These departments came together with their knowledge in genetics and cell biology. Dr. Lang was able to partner with Christopher Cowan, Ph.D., chair of Neuroscience, to test her preclinical model. Dr. Cowan’s lab had been testing mice with a very specific gene, MEF2C. In typical neurodevelopment, there are two functional copies of this gene. MEF2C is a transcription factor that aids in development of multiple body systems, such as the heart, brain, immune, and vascular systems.

Dr. Cowan’s lab was looking at this gene to see its implementation in brain development. Their lab had noticed symptoms that were like ASD behaviors, such as repetitive actions and hyperactivity. They appeared when there was only one functional copy of MEF2C. This became even more interesting when mice with one functional copy of MEF2C also had mild hearing loss.

Noting that there was a potential link between hearing loss and autism spectrum disorder, the team began to investigate further. The researchers found that the activity of the auditory nerve was decreased in these mice who had one functional copy of MEF2C. They even recognized that this hearing loss was very similar to the degeneration of hearing that occurs with increased age.

Hearing Loss and Autism Spectrum Disorder: Study Conclusion

But why was there a reduction in functionality of the auditory nerve? The study concluded that there was increased inflammation around the nerves, vascular degeneration, and immune cell activation. These specific factors caused destruction of the auditory nerve, leading to hearing loss.

“Now we understand that auditory nerve activity can also involve the immune system, and that’s the beautiful new direction we want to continue to study,” Dr. Lang said.

“Now we understand that auditory nerve activity can also involve the immune system, and that’s the beautiful new direction we want to continue to study.”

With these new findings, researchers can continue to investigate the link between hearing loss and autism spectrum disorder. This study helps researchers better understand the MEF2C gene’s role in development and gives a more accurate picture of what is causing the hearing symptoms.

5 strategies for using the myPhonak Junior app to help children learn self-advocacy

Features in the myPhonak Junior app allow children to participate in their hearing healthcare with support from their parents and audiologist.

Do you have children in your practice who are learning how to manage their hearing aids?

Preparing children to advocate for their hearing needs is a process that takes place over several years. It begins early as toddlers hand their parents their hearing aid to let them know that it’s not working.

Later, as children gain dexterity, they want to learn how to put the hearing aid on themselves, and can help with simple care steps such as putting the hearing aids in the charger at night. When children enter school their advocacy needs expand, and they take on more responsibility.

Of course, children’s views about their hearing and devices should be shared freely and should be respected and given due weight given age and maturity of the child.1

There are different ways to support learning these self-advocacy skills. We recently trialed the myPhonak Junior app and believe that it can be a valuable tool in at least these five different ways:

  1. Monitor hearing aid use – the app provides average hours of daily use. Provide a goal, and children can monitor how they are doing as they work towards reaching the target number of hours. Consistent audibility is important for success in school2 and engaging children in managing use can help them practice problem-solving challenges that arise.
  2. Plan for battery charge – the app provides the percent of battery charge. Children can plan for when to charge their hearing aids to make sure the hearing aids are charged and ready for their day. Monitoring battery usage can help children learn hearing aid maintenance skills.
  3. Notice listening environments – the app includes information about noise reduction and speech focus to help children understand which environments may be difficult for them and how to adjust the speech focus slider in the app.
  4. Customize for difficult listening environments – the app allows for adjusting volume, noise reduction and microphone directionality so children can take initiative when they need to make adjustments in those environments.
  5. Learn quick tips & how to use remote support— the app provides tips for children to ensure they are maintaining their devices and learning how to troubleshoot appropriately.

Other quick tips in the app include: “How to use your hearing aid the right way”, “How to maintain your hearing aid the right way”, “Troubleshooting tips if there is no sound coming from your hearing aid”, and “Troubleshooting tips if your hearing aid whistles”.

If more help is needed, parents and children can connect to the audiologist remotely through the app for real-time support.

With our support, children can become strong self-advocates

Parents and audiologists play a critical role in supporting children in learning advocacy skills that are important for effective hearing management. This also supports the idea of Child-Centered Care (CCC) and allows the child to participate in their hearing healthcare with support from their parents and audiologist.

Learning self-advocacy is a process that works towards children being able to:3
·       Describe their own skills and needs
·       Set their own goals and create a plan to reach them
·       Know the how, who, and when to ask for assistance
·       Make decisions and then take the responsibility to deal with the consequences of them.

Resources to help you support parents and children

There are many resources available that promote advocacy.

• Hear to Learn – Help children use and care for hearing devices
• Hands & Voices – Self-advocacy for Deaf and Hard of Hearing students
• Ida Institute – Growing up with hearing loss
• Supporting Success for Children with Hearing loss – Self-advocacy skills for students with hearing loss
• Phonak – Hearing and me templates to talk about hearing loss, Guide to Access Planning (GAP) for teensSelf-advocacy checklist for teens

To learn more about the myPhonak Junior app, please visit www.phonakpro.com.

Deaf comedian makes quarterfinals on AGT

Season 17 of “America’s Got Talent” kicked off at the end of May, 2022. After being inspired by other deaf contestants, deaf comedian Hayden Kristal (they/them/theirs) announced that they wanted to “pursue this for [themselves].” Kristal is now a quarterfinalist after performing a wickedly funny story on episode three of this season’s AGT.

Multitalented Deaf Comedian 

Deaf comedian Hayden Kristal — who identifies as deaf, bisexual, queer, and Jewish — was born into an all hearing family in Colorado. After majoring in sign language and zoology and pursuing a career as a zookeeper, Kristal decided that comedy was their true passion. Kristal jokingly introduces themselves as “a Brooklyn-based former zookeeper who gave up a lucrative career in salamanders to pursue comedy and public speaking” on their website.

“I think…early on, I found that comedy is a language everybody understands,” Hayden said in her pre-performance interview.

“Comedy is a language everybody understand”

Path to Success

Before auditioning for “America’s Got Talent” (AGT) this year, Kristal appeared on “Stand Up NBC” and made it to the semifinals.

“If I say something and you laugh at it, that’s a connection,” Kristal mentions before going on stage. “I always love that feeling.”

For those who have never watched the nationally televised show, America’s Got Talent is a talent competition where contestants from all over the country perform. Celebrity judges decide if a contestant can move from one stage to the next until a winner is crowned with a million dollars in prize money. Currently being filmed in the Pasadena Civic Auditorium, Los Angelos, season 17 is now on its 13th episode.

Kristal presented on week three of AGT a short, yet hilarious, retelling of their application to the Gorilla Foundation. The foundation took care of the famous gorilla Koko, who knew sign language. While using self-deprecating wit, Kristal recounted that their application was rejected due to their deafness. Kristal outlined the discrimination that people with disabilities still receive. They also strung together an ironic tale that impressed both the judges and audience.

While Kristal started the performance in sign language, confusing the audience and judges, Kristal presented the rest of their story verbally with the help of sign language interpreter Julie. Although Kristal jokes that “I do like to start [with sign language] ’cause [it] makes heckling me a ADA violation,” Kristal performs most of their comedy sets in English.

On YouTube, Kristal’s performance has over 745K views. One user commented, “Now that’s what I call comedic timing! She put me on the floor.” Simon Cowell, known for being hard to please, added that it was “brilliantly funny.” Needless to say, Kristal earned an unanimous vote to proceed to the next stage of the competition.

Inspired by Past Comedians 

When asked why they wanted to compete on AGT, Hayden talked about past competitors whose performances encouraged them to pursue stand-up comedy. “This is one of the biggest stages in the world, and watching some of the people that AGT has given opportunities to has given me more confidence to pursue this for myself,” they said in the audition video.

During her performance, Kristal called out two particular comedians as her inspiration: D.J. Demers, a Phonak “hEARo” and deaf comedian who appeared on AGT in 2016, and Drew Lynch, a comedian with a speech impediment, who was runner-up of the 10th season.

“When I see other people with disabilities on this stage and thriving, I know that they were given the tools to be able to succeed here,” Kristal said before their AGT performance.

Read more: Talking with deaf comedian D.J. Demers on World Laughter Day

Activist

As deaf comedian, Kristal is also an activist. Over the past few years, they have spoken at many conferences and colleges across the country. In 2016, Kristal hosted their first Ted Talk on Intersectional Disability. With 660K followers on TikTok, Kristal uses their platform to explore “the intersections of ability, gender, sexuality, and access, particularly within the spheres of activism and social justice.”

Kristal’s past programs have included “Laughing Out Loud: Bridging Social Gaps Through Comedy” and “Lessons From My Deafblind Dog.” As one user commented, “So proud of Hayden. I follow [them] on TikTok and once I found out [they were] on AGT I was so happy for [them] and I just had to go watch it!”

Kristal is not sure what is waiting ahead, but as they said after the successful AGT audition, “to be here [performing], it’s unbelievable and I felt like I already won just making it to tonight.”

“America’s Got Talent” airs Tuesdays and Wednesdays at 8pm EST on NBC.

Scientists discover “master gene” that regrows dead ear hair cells

Scientists in the U.S. have discovered a “master gene” that can regrow lost ear hair cells. It is known as TBX2.

Ear Hair Cells

TBX2 functions by directing ear cells to produce inner or outer hair cells, according to the findings, which were published in the journal Nature. For human hearing to work, we need both types of ear hair cells to work together. Inner hair cells transmit to the brain. Outer hair cells, which amplify sound, are frequently damaged by factors like age, medications, or even substance abuse. If the outer hair cells are missing or damaged, signals don’t get to the inner hair cells. As a result, they aren’t sent to the brain, and we don’t hear the sound.

Ear hair cell loss is a significant cause of hearing loss, resulting in sensorineural hearing loss, or SNHL – the type of hearing loss responsible for around 90 percent of hearing loss. The other 10 percent is usually attributed to conductive hearing loss or some form of blockage in the ear. Hair cells are sensory receptors within the ear that are essential towards processing sound. Lost or damaged ear hair cells reduce hearing capacity and contribute heavily towards hearing loss.

What Does TBX2 Do?

Scientists now believe they can reproduce these essential ear hair cells to replace those lost to age or damage. Recreating these cells is a significant step forward. This could be the start of a new form of gene therapy for hearing loss, according to researchers.

“This could be the start of a new form of gene therapy for hearing loss.”

The discovery builds on existing science whereby researchers can create artificial hair cells. However, these cells cannot develop into inner or outer ear hair cells, which is where TBX2 fits in. Researchers at Northwestern University investigated ear hair cells in mice and revealed that TBX2 is a regulator of inner ear hair cell versus outer ear hair cell production. Scientists analyzed hair cell creation concerning inner and outer ear hair cells. When a hair cell was created, blocking the TBX2 gene ensured that the cell was an outer hair cell.

Read more: Researchers find a drug combination that could regenerate ear hair cells

What Happens Next?

While the discovery is a major step forward in neuroscience, it’s uncertain what happens next. Scientists hope to figure out how to use this new knowledge to create a cell development process that may be usable in treating hearing loss. Currently, it’s possible to create artificial hair cells. This method can’t differentiate between inner and outer hair cells, so some work still needs to be done.

In theory, if scientists can regrow ear hair cells, then they are one step further towards repairing or restoring lost hearing. However, there is still a long way to go. There’s no guarantee that this discovery will in any way lead to a “cure” for hearing loss. It does offer some hope, however, that ear hair cells might be replaceable one day.