How Hearing Aids Promote Speech Clarity in Noisy Places

Using a slow, modulation based algorithm, modern hearing aids excel at promoting speech clarity. New circuits raise the speech-to-noise ratio resulting in increased word discrimination. In other words, the hearing aid identifies and amplifies speech while reducing surrounding noises. The circuit can differentiate speech from noise due to the natural pauses and inflections unique to spoken word.

Also, hearing aids identify the type of noise and employ different strategies to minimize it. Noises are identified as either "impulse" or "continuous" and are reduced with varying "attack and release" strategies. Sudden, harsh sounds are neutralized while other sounds are appropriately enhanced. Modern hearing instruments work to suppress all types of surrounding noise from multiple directions simultaneously while also following the source of speech. This feature empowers the hearing aid to analyze the current listening environment, identify the source of speech (front, beside, behind), and select the appropriate microphone configuration to promote the highest level of speech intelligibility for the listener. This enables the hearing aid wearer to:

• Hear passengers speaking from the backseat while driving a car
• Participate in conversations in noisy environments like restaurants
• Hear the caregiver who is pushing the wheelchair

Click here for more information on how the Siemens Micon promotes speech clarity in noisy environments.

Hearing Aids Learn How You Like to Listen

Hearing instrument users can teach their devices how they like to listen in different environments. The user can teach the hearing aids preferred gain, compression, and frequency shape for various acoustic environments using simple volume control adjustments. Empowered by a sophisticated learning algorithm, the hearing instrument continuously monitors the personal modifications made by an individual in different listening environments. The hearing aid wearer is able to teach the hearing aid personal listening preferences in up to six different acoustic environments including:

1. Quiet
2. Car
3. Music
4. Noise
5. Speech in Noise
6. Speech in Quiet

Not all hearing aids have this programming feature so be sure to work with your audiologist to choose the right devices for your particular hearing loss, lifestyle, and budget!

For more information on new features in hearing aids, click here! 

How Your Hands Impact Your Hearing

Researchers at Georgetown University Medical Center have discovered how the left and right hemispheres of the brain process auditory information differently. Researchers hope the newly discovered link between motor skills and perception will eventually lead to breakthroughs in how language disorders are treated.

Peter Turkeltaub, MD, PhD, one of the lead researchers in the study had this to say about the research and its findings:

We asked the subjects to respond to sounds hidden in background noise. Each subject was told to use their right hand to respond during the first 20 sounds, then their left hand for the next 20 second, then right, then left, and so on. When a subject was using their right hand, they heard the rapidly changing sounds more often than when they used their left hand, and vice versa for the slowly changing sounds. Since the left hemisphere controls the right hand and vice versa, these results demonstrate that the two hemispheres specialize in different kinds of sounds—the left hemisphere likes rapidly changing sounds, such as consonants, and the right hemisphere likes slowly changing sounds, such as syllables or intonation. These results also demonstrate the interaction between motor systems and perception. It’s really pretty amazing. Imagine you’re waving an American flag while listening to one of the presidential candidates. The speech will actually sound slightly different to you depending on whether the flag is in your left hand or your right hand.

If we can understand the basic brain organization for audition, this might ultimately lead to new treatments for people who have speech recognition problems due to stroke or other brain injury. Understanding better the specific roles of the two hemispheres in auditory processing will be a big step in that direction. If we find that people with aphasia, who typically have injuries to the left hemisphere, have difficulty recognizing speech because of problems with low-level auditory perception of rapidly changing sounds, maybe training the specific auditory processing deficits will improve their ability to recognize speech.

For the source of this article and more information about Dr. Turkeltaub's research, click here.


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The Future of Tinnitus Treatment

An implantable device that stimulates the vagus nerve may be the future of tinnitus treatment. In 2011, researchers at the University of Texas at Dallas successfully reduced the symptoms of tinnitus in test subjects by stimulating the vagus nerve and introducing audible tones different from the tones generated by the tinnitus.  The vagus nerve is involved in several involuntary functions such as heart rate, digestion, and reflex responses. It extends from the brain stem into the abdomen contacting the heart, lungs, larynx, stomach, intestines, and ears. Using an implantable device manufactured by MicroTransponder, Inc. called "Serenity" Drs. Michael Kilgard and Robert Tennaker hope to give individuals suffering from tinnitus an immediate and effective method of treatment by stimulating this nerve. At the onset of tinnitus, an individual would push a button to both begin stimulation of the vagus nerve using the Serenity device and introduce tones that were different from the tones generated by the tinnitus. In the first round of human trials,  many patients showed dramatic and long lasting improvement in the severity of the tinnitus.

Researchers hope to continue clinical trials and submit an application for approval to the Food and Drug Administration as early as 2014.

For more information on this research, read the following articles:

Article 1
Article 2

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Study: Hearing Loss Increases Risk of Falling?

New research from Johns Hopkins School of Medicine shows that people with hearing loss have an increased risk of falling. After examining over 2000 adults aged 40-69, Drs. Frank Lin and Luigi Ferrucci concluded the following:

...people with a 25-decibel hearing loss, classified as mild, were nearly three times more likely to have a history of falling. Every additional 10 decibels of hearing loss increased the chances of falling by 1.4-fold. This finding still held true even when other factors linked with falling, including age, sex, race, cardiovascular disease and vestibular function were accounted for.
 

Commenting on these findings, Dr. Lin states:

Gait and balance are things most people take for granted, but they are actually very cognitively demanding. If hearing loss imposes a cognitive load, there may be fewer cognitive resources to help with maintaining balance and gait.
 

There are various theories as to why there is a link between falling and hearing loss. Researchers theorize that people with hearing loss become less aware of their overall environment and therefore more susceptible to falling. Another potential explanation is that the hearing loss causes undue stress on the brain leading to its inability to properly monitor the surrounding environment. In any case, researchers hope to find ways to prevent injuries caused by falls linked to hearing loss.

For the source of this information and more details on the research findings, click here.

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A Cure for Noise-Induced Hearing Loss?

Researchers in New Zealand have discovered a compound that seems to reverse noise-induced hearing loss. The drug, called ADAC, was shown to restore varying degrees of hearing that had been lost due to loud noise exposure. In theory, the ADAC compound works by revitalizing cells in the cochlea that are responsible for hearing. A higher degree of hearing was restored in test subjects that were given doses of ADAC within six hours of the initial exposure to loud noise. Also, test subjects regained a larger percentage of their hearing capacity when treated with ADAC consistently over a period of five days.

Click here for the source of the information shared in this article and for more details on the actual research.

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How Loud Noise Exposure Can Lead to Tinnitus

Tinnitus (ringing in the ears) has over 200 potential causes.  Damage to nerve cells in the inner ear caused by loud noise exposure can lead to the onset of tinnitus.  The nerve cells of the inner ear receive auditory information and send it along the auditory pathway to be interpreted by the brain. Repeated exposure to loud noise can damage the hair-like nerve cells and lead to hearing loss.  Recent theories on the origin of tinnitus caused by hearing loss suggest that when the brain receives auditory stimuli that has missing frequencies, it attempts to generate those frequencies that are absent (frequencies that are not "heard" due to hearing loss). The sounds we hear as tinnitus are the result of the brain's attempt to generate the auditory information it is no longer receiving due to noise induced hearing loss.

 

For more information on tinnitus, visit our website! 

 

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Secondhand Smoke and Hearing Loss in Adolescents

Researchers from the New York University Langone Medical Center have discovered a possible link between exposure to tobacco smoke and hearing loss in teenagers. Cotinine is a substance formed in the blood as the byproduct of tobacco smoke inhalation. The amount of cotinine in the blood reveals the individual’s level of exposure to tobacco smoke. A higher level indicates that the individual is an active tobacco smoker while lower levels suggest an individual is consistently in the presence of someone who smokes. Researchers compared the blood level of cotinine with hearing test results for low, mid, and high frequencies among 1500 teenagers. Their research discovered the following:

• Teenagers who have consistently been exposed to secondhand tobacco smoke are almost twice as likely to develop hearing loss as those with little or no exposure. 
• Hearing loss in the lower frequencies was more prominent among teenagers with lesser degress of exposure
• Hearing loss in the mid and high frequencies was more prominent among the teenagers with the highest levels of cotinin. Because the audible range of speech is in the mid and high frequencies, this is particularly troublesome.

For more information about this study, read the article from Reuters or view this report from ABC News.


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Who would benefit from waterproof hearing aids?

Individuals who would benefit from a waterproof hearing aid include:

• People who enjoy an active lifestyle and like to play golf, kayak, swim, hike, or power walk
• People who work in dusty environments
• People who perspire heavily
• People who exercise and need hearing aids to hear instructions or listen to music through Bluetooth transmission

Siemens Hearing Instruments is currently the only hearing aid manufacturer to offer a waterproof hearing aid. The Siemens Aquaris features advanced technology with six automatic programming options including a road noise reduction program and directional microphones that empower the device to pick up speech from beside and/or behind the listener (great for teachers who must turn away from students to write down information). With a bluetooth remote, it is also possible to improve speech understanding while conversing on a landline or cell phone. Also, the Aquaris is ideal for people who produce alot of ear wax because it is not a receiver-in-the-ear model. It is powered by a disposable size 13 battery giving it superior battery life to size 10 and 312 battery-powered devices.

The Aquaris comes with a three year warranty for loss and damage and is available for people with a mild to moderately severe hearing loss. Siemens hopes to offer the Aquaris for individuals with a severe to profound hearing loss in late 2013.

Who would benefit from water-resistant hearing aids?