Noise affects sound processing in the brain more rapidly than ageing

July 2019 earth.com news

The two most common types of hearing loss are caused by ageing and exposure to excessive noise. In both cases, the hairs or nerve cells in the cochlea that are responsible for sending sound signals to the brain are progressively affected.  When the hairs or nerve cells become damaged or missing, the electrical brain signals are not transmitted effectively and sounds are not processed as well. At this point, it may be difficult to recognise words in the presence of background noise and higher pitched tones often become muffled.

Despite similarities in the effects of age- and noise-related hearing loss, however, a new study from theSociety for Neuroscience has found that these two conditions impact sound processing in the brain on different timescales. The research suggests that each type of hearing loss should have its own unique treatment.

A research team led by Michael Heinz and Kenneth Henry set out to observe how the auditory nerve encodes sounds. The experts used a chinchilla model of age-related hearing loss, which is the traditional animal model for most types of research related to the ear. This is due to the fact that chinchillas have inner ear anatomy that is very similar to humans. Next, the researchers compared their results to data from a chinchilla model of noise-induced hearing damage. They found that the same level of sound sensitivity loss caused more severe processing changes in the auditory nerve of chinchillas with noise-induced hearing loss compared to those with age-related hearing loss. 

The study revealed that mild noise-induced hearing loss caused the same amount of processing impairment as moderate to severe age-related hearing loss. The findings emphasise the need for hearing-safety awareness, as well as for more customised treatments of hearing loss.

As vaccine opposition grows, survivors of measles, mumps and rubella warn of lifelong effects, including vision loss, deafness: ‘How different my life would have been’

July 2019 Chicago Tribune

Marsha Engle-Reinecke; at age 4, she had measles resulting in extreme hearing loss because the measles vaccination was not yet available.

As her fever rose higher and higher, Marsha Engle-Reinecke began to hallucinate. She could see black birds with big, sharp beaks, she recalled — there were hundreds of them, flying at her, intent on poking out her eyes. Engle-Reinecke survived the punishing childhood fever — and even managed to outgrow her fear of birds — but measles left a lasting legacy, in the form of a severe hearing impairment. Today, she has no hearing in her right ear and about 10% of normal hearing in her left. In college she had to give up her dream of becoming a teacher, and as her hearing worsened, she was forced to abandon a 25-year career in brand management. “How different my life would have been,” said, Engle-Reinecke, 61, a longtime resident of Geneva who recently moved to Los Altos Hills, Calif. “It’s been a good life. But how different my opportunities would have been and how much easier my day would have been, had I not had a disability.”

Disabilities due to vaccine-preventable illnesses such as measles, mumps and rubella — including blindness, deafness and permanent brain damage — are rarely discussed in an increasingly heated national debate over vaccine avoidance, in part because discussion tends to focus on the more dramatic risk of death, in part because it’s no longer common to know someone living with the lifelong effects of a serious childhood illness. But the risk of disability remains one of the most important reasons to vaccinate, according to Patsy Stinchfield, senior director of infection prevention and control at Children’s Minnesota hospitals and clinics. “(People) look around, and they don’t see polio. They don’t see measles. They don’t see the disabilities. It’s invisible,” said Stinchfield, senior director of infection prevention and control at Children’s Minnesota hospitals and clinics. “And the trouble is, it’s not only young parents, but young providers who don’t know. Those of us who do know need to keep reminding people: We do not want to go back to death and disability from vaccine-preventable diseases.”

Concern about declining vaccination rates recently motivated Engle-Reinecke, who got measles before a vaccine was available, to post about her hearing loss on Facebook, concluding: “A vaccine would have made such a difference in my life. Please vaccinate your children.”

Ophthalmic technician Mariah Easley puts drops in the eyes of Traci Cobb-Evans who was born with cataracts and a damaged optic nerve due to rubella.

Two other Chicago-area survivors of vaccine-preventable childhood illnesses, Dan Flaherty, who is deaf in one ear due to mumps, and Traci Cobb-Evans, who has severe visual impairment because her mother had rubella during pregnancy, also agreed to talk about the lifelong effects of their illnesses. Cobb-Evans, 56, was born with cataracts in both eyes, dislocated lenses and a damaged right optic nerve, she said. She’s legally blind in her right eye, through which she can see that a person is present and has, say, a red shirt, but can’t make out facial features. Her left eye, which has a cataract and a dislocated lens, can be corrected to about 20/30 vision, much to the surprise of her eye doctors. “They don’t understand why I see as well as I do out of the better eye,” said Cobb-Evans, a Chicago Public Schools special education teacher. “The cataract covers all except a pinhead. They don’t know why I’m seeing all around that. It amazes them.”

Measles cases are on the rise in the United States, with 1,109 confirmed cases this year, the most since 1992. Of all the counties nationwide, Cook County is most at risk for a widespread measles outbreak, according to a May study in the journal The Lancet Infectious Diseases, due largely to the number of international flights arriving from countries where parents are increasingly hesitant to vaccinate their children.

The risk of death from measles was about 1 in 500 between 1985 and 1992, according to the Centres for Disease Control. Acute encephalitis, a dangerous brain inflammation, occurs in about 1 in 1,000 measles cases. The federal government doesn’t collect data on the long-term outcomes of those encephalitis cases, but Stinchfield said the risks are serious. “Most people don’t come out of that the same person,” she said. “They come out with some permanent brain damage; they come out of it with some disabilities. They may come out of it with deafness. Blindness is a possibility.”

For every 1 million vaccines given, approximately 1 person is compensated for an alleged vaccine-related injury, according to the U.S. Health Resources and Services Administration. And compensation does not necessarily mean that the vaccine was found to have caused the injury.

Vaccine opponents continue to voice concerns that vaccines cause autism, despite studies showing no link. Some vaccine opponents also express distrust of the government and the medical establishment, and question whether vaccines are really necessary in an era when illnesses such as measles are rare.

Engle-Reinecke, Flaherty and Cobb-Evans have all found ways to navigate the workplace successfully. Flaherty, 55, of Itasca, said that when he worked as an elementary school principal, students knew that they had to tap him on the elbow to get his attention. Asked how his hearing loss affects him now, he responded with a chuckle. “It makes life miserable lots of times,” he said, in part because it’s hard for him to discern what one person is saying in a noisy room. “If I’m at a party and everybody’s talking, I’m pretty much just daydreaming and staring into space,” he said.

Engle-Reinecke, who comes from a family of teachers, said she had to give up her dream of going into the profession due to her hearing loss. In college, she switched her major to business and went on to work for Clairol and Alberto Culver. She wrote the text for a 2010 book, “100 Sounds to See,” in which she celebrated sounds she had never heard or increasingly couldn’t hear, such as the sound of the wind or the thwack of a bat on a ball. She jokes that there are upsides to hearing loss — she can’t hear her husband snore — but grows serious when she talks about vaccination. She recalled that a cousin got very sick with polio when she was a girl, and described the scene when she lined up to get her polio vaccine. “It was a big deal — it was almost celebratory,” she said. “There was such an appreciation because so many people had been harmed by polio. It was a horrible thing.”

In elementary school, Cobb-Evans was told that she could grow up to be one of two things, due to her vision loss: a court stenographer or a secretary. Her mother had other ideas, introducing Cobb-Evans to sign language classes at age 12. Cobb-Evans went on to be a teacher of the deaf and hard of hearing for Chicago Public Schools. She has also worked as legislative issues coordinator for the Chicago Teachers Union, and in 1994, she took a leave of absence from CPS to restructure the deaf education program at Northern Mariana Islands public schools. At one point, she had a CPS student with disabilities due to rubella, and the student’s mother informed Cobb-Evans she’d been told that her son couldn’t grow up to “do anything.” Later, the student’s mother pointed Cobb-Evans out to other parents, saying, “That’s the teacher I was telling you about! She had rubella, she had cataracts — and look at her.”

Flaherty, whose four children were all vaccinated, finds it hard to understand why parents wouldn’t take that step. Engle-Reinecke said she got upset recently when she heard about a parent who wasn’t vaccinating her child: “What I wouldn’t give to have (been vaccinated).” For Cobb-Evans, too, the issue is personal. “They could have children like me — or worse,” she said of women who aren’t vaccinated against rubella. I thank God every day because I know it could have been worse. Heart, eyes, ears — all of that. I know what it can do.”

Hearing Loss and Hearing Solutions - A Guide

Here at last is our 2018 revision of the "Hearing Loss and Hearing Solutions - A Guide" that we have published in PDF format for the enjoyment of users. Our original version was reviewed very favourably and attracted a lot of viewers.

You can view/download it from this link:  Hearing Loss and Hearing Resources - A Guide (91 pages, 2.4 MB size). 

We welcome edits, corrections, updates, suggestions etc. Contact the authors via email: This email address is being protected from spambots. You need JavaScript enabled to view it..

Here are some of the professional comments about our new 2018 version.

Overall Reactions to Second Edition:
Monica Bray (Cochlear): I’ve just discovered the wonderful Hearing Guide. It's an awesome resource.
Jade Parr (Advanced Bionics): What a great resource.
Roberta Marino (Fiona Stanley Hospital) with permission:
I really enjoyed reading the guide!  It's brilliant. So comprehensive, easy to read and relatable. I'm really impressed with the level of detail and can only imagine the hours you've spent researching new updates. The guide will positively impact so many people including professionals.  I can see it being so useful for instance, at our hospital when new medicos have a rotation in the Ear, Nose and Throat Department or when we have new Audiology students in our Department who are new to implant devices. Again - well done!  It's fantastic there's people like you who are so pro-active and care enough to put in the hundreds of hours required to develop such a useful and thorough guide.

Overall Reactions to First Edition:
Margaret Anderson: It's going to be a great resource for consumers and all sorts of people. Well done for tackling it!
Marie-Louise Hekel: Congratulations on this most thorough publication. You have done a splendid job. It would be a very valuable resource, not only for hearing impaired people, but professional audiologists in particular.
Roberta Marino: I think you’ve done a brilliant job. You really have a great understanding of how the different devices can be applied. If you don’t mind, when the product is finished, I’d like to pass it on to training ENT’s at the major teaching hospitals here in Perth and also the upcoming Audiology students.
Sarah McCullough (Advanced Bionics): Well done on all your hard work
Linda Ballam-Davies (Cochlear): It looks great and you've done a top job.