Posts tagged hearing impaired
Single-sided deafness (SSD) does not affect only your hearing, but it can result in a difficulty understanding speech and other cognitive issues. It is something you may want to look into before the condition becomes permanent. Currently, Contralateral Routing of Signals (CROS) hearing aids are the only treatment for single-sided deafness, but they are not as effective as they should be. However, scientists may have discovered a way to treat people suffering from SSD.
Symptoms and Treatment of Single-Sided Deafness
Around 60,000 people in the United States are affected by single-sided deafness. Physical trauma, microtia, meningitis, Waardenburg synodrome, acoustic neuroma and many other viral infections and brain tumors are known causes of the condition.
Unfortunately, patients have to deal with quite a few debilitating symptoms, including:
- Difficulty hearing,
- Trouble filtering out background noise,
- Struggle determining sound direction,
- Understanding speech,
- Interpersonal communication difficulties,
- Frequent headaches, and
A New Discovery in Brain Plasticity
Finding the best treatment for single-sided deafness has been a challenging task for scientists. The hardest part is measuring how effective the treatment is in resolving the disorder. However, researchers who conducted a new study at the University of California believe they have found a lead to a cure.
Researchers learned more about brain plasticity, which is the ability of the brain to modify its own structure when encountering changes within the body. This information can help scientists figure out how the brain works, how to proceed using this knowledge to overcome injures, and how to make devices, like hearing aids, more effective.
Scientists tested 26 subjects, including 13 people with SSD, and 13 with normal hearing. Using magnetoencephalographic imaging (MEGI), as well as fMRI scans, researchers were able to observe changes in the brain – specifically within the subjects’ auditory cortices. They discovered that when the patients were exposed to sound at different frequencies, the neurons in the brain activated across both hemispheres.
However, for the patients with SSD, the spread of neuron activation was more prominent in one hemisphere, but much less in the other. The other group of patients with normal hearing showed a symmetrical display within both hemispheres of the brain.
Scientists hope that these results will help them create biomarkers, which will allow them to measure the efficiency of future treatment options. They also believe that potential therapies using brain stimulation may be able to restore hearing and cure SSD.
A new study by the Johns Hopkins Comprehensive Neurofibromatosis Center reveals some interesting details about an anticancer drug. Researchers discovered that the drug has restored hearing for some patients suffering from Neurofibromatosis Type II. This is positive news for those dealing with both hearing loss and cancer.
Neurofibromatosis Type II
Neurofibromatosis Type II (NF2) is a rare disorder that affects an estimated one in 25,000 people. This illness causes vestibular schwannomas (slow-growing tumors) to form on the eighth cranial nerves. These cranial nerves contain the acoustic and vestibular branches. The acoustic is responsible for hearing, while the vestibular regulates the body’s equilibrium, or balance.
As the tumors grow, they press against the brain stem and interrupt the function of these branches. Most patients suffering from neurofibromatosis begin to develop hearing loss, and the disease eventually leads to deafness.
Bevacizumab: The Anticancer Drug
The vestibular schwannomas that are responsible for hearing loss produce high levels of proteins called VEGF. These proteins cause blood vessel to grow, which feeds tumors.
For the study, researchers treated 14 patients with both NF2 and progressive hearing loss, using an anticancer drug called Bevacizumab. The drug reduces the VEGF levels in certain cancers. The patients received Bevacizumab intravenously every three weeks for 48 weeks. After the treatment was finished, the patient underwent an additional 24 weeks of observation.
The results were positive. Twelve patients went from non-serviceable to serviceable hearing in the affected ear, according to the Gardner-Robertson scale. Five of those patients maintained improvement in hearing for six months after they stopped taking the drug.
While the drug has managed to show improvements in hearing, there are some side effects. The drug can cause slower wound healing, high blood pressure and bleeding. Three of the patients who participated in the study experienced some of these side effects. The anticancer drug also costs up to $5,000 per dose.
Dr. Jaishri Blackeley, director of the Johns Hopkins Comprehensive Neurofibromatosis Center, remains optimistic. “Our study shows that the hearing loss suffered by at least a subset of these patients isn’t permanent and that there is hope of reversing it,” says Dr. Blakeley. “The trial results, although limited by the small number of patients, suggest that patients may not need to get doses of drug as frequently as may be required for cancer and also may be able to take breaks in treatment. This may help reduce the frequency of negative side effects and control long-term health care costs.”
When you think of hearing aids, you get the image of a contraption wrapped around someone’s ear. That’s the same image everyone gets. It’s also the reason people who suffer from hearing loss avoid getting the devices. They feel like it is some form of universal signifier that they are officially getting old. However, what if you could surgically have a hearing implant placed into your ear?
Esteem: A New Hearing Implant
“Esteem,” a new implantable hearing device, has been created by Envoy Medical Corporation. The new hearing implant was developed for patients with moderate-to-severe nerve-related hearing impairment. The company’s primary goal is to allow patients to hear again with 100 percent clarity, and return to a normal quality of life.
The University of Missouri’s Ear, Nose and Throat Center recently started offering the hearing implant to patients. In fact, they are the only health provider in the state to do so.
In order for the implant to be placed into a patient’s ear, they need to have a mastoid and middle-ear cavity, which most people have. However, patients’ ears are thoroughly reviewed through a CT scan before the device is implanted.
There are high expectations for the device. As the only doctor certified to provide the surgical procedure to patients in Missouri, Dr. Arnaldo Rivera states, “This device will allow the patient to do everyday activities such as showering and swimming that a typical hearing aid would need to be removed for.”
Returning people to fully enjoying everyday activities is a big part of Envoy Medical’s mission. Their hearing implants are waterproof, they filter wind naturally, and are designed for sleeping. It also features a battery that can last from four-and-a-half to nine years, depending on how it is used. These are features not normally found in other hearing devices.
For people interested in the Esteem hearing implant, it costs $33,000 for the device and procedure. Envoy Medical is making sure that hearing loss does not become a permanent disability.
People have an initial fear that nothing will sound the same if they lose their hearing. However, there may be hope. Scientists are looking to re-engineer cochlear implants to make music sound more appealing to the ears.
The Problem with Music
Most cochlear implants are designed to process speech. However, they have trouble when it comes to music. Many people with the implant report improvements in understanding, hearing and speech, but listening to music becomes less enjoyable.
“I’ve had the implant for 15 years now and it has done so much for me. Before I got the implant, I was working but I could not use a phone, I needed somebody to take notes for me at meetings, and I couldn’t have conversations with more than one person. I can now use a phone, I recognize people’s voices, I go to films, but music is awful,” says Prudence Garcia-Renart, a musician who gave up playing the piano a few years ago.
Auditory neurons that transmit signals to the brain are lost with severe hearing loss. Speech is a simple auditory signal, making it easier for implants to process. The same can’t be said for music. Implants are not able to compensate for the loss of auditory neurons.
Upgrades to Cochlear Implants
Scientists are hoping to help people like Prudence find a solution for enjoying music. Instead of engineering a cochlear implant to make up for lost auditory neurons, scientists are trying to re-engineer music. “You don’t necessarily need the entire piece to enjoy the music,” says Anil Lalwani, MD, director of the Columbia Cochlear Implant Program. “Even though a song may have very complex layers, you can sometimes just enjoy the vocals, or you can just enjoy the instruments.”
Currently, Dr. Lalwani and his team are trying to learn which parts of music are the most important for enjoyment. They believe that software will be able to convert music for listeners. “Our eventual goal, though, is to compose music for people with cochlear implants based on what we’ve learned,” Dr. Lalwani says. “Original pieces of music that will possibly have less rhythmic instruments, less reverb, possibly more vocals—something that is actually designed for them.”
Sometimes, hearing loss can occur because of a variety of reasons: buildup of earwax, an ear infection, or even exposure to loud noises. Many people believe having a little trouble hearing every now and then is a minor inconvenience, and that the condition is only temporary. However, a new study suggests the sound deprivation can lead to irreversible hearing loss.
How Is Sound Deprivation Affecting Hearing?
When sound’s ability to travel between the ear canal and the inner ear is damaged, conductive hearing loss occurs. Sounds and voices will seem faint or muffled to anyone suffering with the disorder. In the study, performed by the Massachusetts Eye and Ear Infirmary, scientists wanted to be able to determine what happens to people with a recurring case of hearing loss.
By testing mice dealing with chronic conductive hearing loss in one ear, they were able to determine that sound deprivation causes irreversible damage to the inner ear.
“After a year of sound deprivation, we observed dramatic changes in the inner ear – notably, a significant loss of the synaptic connections through which the sensory cells send their electrical signals to the brain,” says Stephane F. Maison, Ph.D., lead researcher, investigator in the Eaton-Peabody Laboratories at Massachusetts Eye and Ear Infirmary, and assistant professor of otolaryngology at Harvard Medical School.
What About Your Good Ear?
Even with the damage from sound deprivation, some individuals feel that not being able to hear from one ear is not a situation worth fixing.
“Although these conditions are routinely treated in industrial societies, a number of patients choose not to receive treatment, particularly when their medical condition affects only one ear,” Dr. Maison said. “For instance, patients with unilateral atresia, a condition in which the ear canal is closed or absent, see limited benefits of undergoing surgery when they can simply use their good ear.”
However, choosing not to deal with hearing loss is not a wise decision. Other studies have shown how a lack of hearing can affect memory and speech. The same is true for those with children dealing with hearing loss or ear infections, as it can be the causes of dizziness and balance problems. With the research in this study, Dr. Maison advises that “audiologists and physicians should advocate for early intervention and treat these middle ear conditions.”
University of New South Wales (UNSW) researchers have answered the enduring question of how the brain processes hearing between our ears, which is essential for localizing sound, hearing in noisy conditions and protecting us from noise damage. This study should get many hearing specialists excited.
The landmark animal study also provides new insight into hearing loss and is likely to improve cochlear implants and hearing aids. A cochlear implant is a surgically implanted electronic hearing device that helps amplify sound for a profoundly deaf person or for someone with severe hearing.
The reason for cochlear implants is that they provide hearing to nearly deaf persons who have damaged sensory hair cells in their cochleas. In these patients, the implants provide enough hearing in order to understand speech. However, the quality of sound differs from natural hearing, because the brain receives less natural sound information to interpret it. Yet the implants offer enough for the patient to hear and understand speech and environmental sounds.
UNSW Professor Gary Housley, senior author of the research paper, said his team’s primary aim was to understand the biological process behind the ‘olivocochlear’ hearing control reflex. The professor added, “The balance of hearing between the ears and how we discriminate between sounds versus noise is dependent upon this neural reflex that links the cochlea of each ear via the brain’s auditory control centre.
The key to this finding is that the researchers were able to fully understand how the olivocochlear reflex works. Professor Housley stated, “When sound intensity increases, the olivocochlear reflex turns down the ‘cochlear amplifier’ to dynamically balance the input of each ear for optimal hearing, sound localisation and to protect hearing.”
Another important aspect of this study found that the cochlear’s outer hair cells, which amplify sound vibrations, also provide the sensory signal to the brain for dynamic feedback control of sound amplification, through a small group of auditory nerve/sensory fibers that were previously misunderstood.
The researchers, using mice, discovered how the olivocochlear reflex in each ear communicates with the cochlear auditory sensory fibers, and this feedback loop allows the brain to balance sound in the environment.
Professor’s Housley’s team further speculated that hearing loss humans experience from old age may be related to the gradual breakdown of these sensory fibers connected to the outer hair cells.
“A major limitation of hearing aids and cochlear implants is their inability to work in tandem and support good hearing in noisy conditions,” Professor Housley also added. “The ultimate goal is for cochlear implants in both ears to communicate with each other so that the brain can receive the most accurate soundscape possible.” This research helps hearing specialists improve cochlear implant devices so that we can create a more natural and effective learning device for those with hearing loss.
It may be a subject many do not think about, but hearing loss is prevalent. Statistics are showing dramatic numbers when it comes to damaged or lost hearing. In the United States these numbers were recently polled and show a large percentage of the population to be dealing with these types of issues. The facts show that age and varying degrees of deafness can be found: These ranges are from infants to the elderly and from minor loss of hearing to deafness. Here is a look at what was found and what you can do if you find yourself battling with hearing loss.
Today the number of persons with hearing loss has far surpassed what was estimated a few years ago; in fact, the number has nearly doubled. Almost 50 million Americans find themselves with hearing difficulty in at least one ear. Of course, as a person ages, it is common to experience hearing loss. As age increases, so does the percentage of those experiencing some of these difficulties. However, there is still about one-fifth of the population from childhood onwards that has enough hearing loss so as to impede communication. That being said, a handful of newborns (out of 1,000) are born deaf or are hard of hearing. Factoring in the millions who have experienced hearing damage due to work conditions or leisure activities, and we see the figures begin to round out. Also, statistics show that the majority of war veterans will experience some form of hearing impairment as well. One source states that hearing loss among war vets is even more prevalent than Post-traumatic Stress Disorder.
Should one find themselves in a position where their hearing is impaired or lost, there are specialists that can help. Auditory evaluations can be preformed to help determine cause and course of treatment for hearing loss. Reducing the amount of people who suffer from hearing loss is possible, and your ear, nose and throat specialist is ready to help.