Tag Archives: hearing aid

How a deaf Beethoven discovered bone conduction by attaching a rod to his piano and clenching it in his teeth

On May 7, 1824, the legendary 9th Symphony premiered in the Theater am Kärntnertor in Vienna. When the masterful performance ended, 54-year-old Beethoven, who was stone deaf at this time, was still conducting along with the “official conductor” from the front row when he had to be turned around to face the thunder of an applauding audience.

Whilst Beethoven’s career was the stuff of genius, his personal life was marked by a struggle against deafness and constant suffering caused by an armada of afflictions. The German composer first noticed that his hearing was fading around the age of 28. By this time he was already an established figure in the Vienna musical scene and regarded as a rising star rivaling Wolfgang Amadeus Mozart, which only made everything worse.

One can only imagine how cruel a fate that must have felt like to such a musical mind. He, the great Beethoven, of all people, was going deaf! It’s as if Picasso lost his eyesight or Rodin had his arms cut off.

But Beethoven was a strong-willed spirit who didn’t give up easily. One of his celebrated phrases is: “I will choke on the throat of fate, it will never make me succumb.”

He was true to his word. Despite his rapidly deteriorating hearing, from 1803 to 1812, Beethoven composed an opera, six symphonies, four solo concerti, five string quartets, six-string sonatas, seven piano sonatas, five sets of piano variations, four overtures, four trios, two sextets, and 72 songs.

Beethoven… the inventor?

Despite living in pain, Beethoven did not give up. However, he had a helping hand. In order to continue composing and playing music, Beethoven stumbled across a physical phenomenon that is central to hearing: bone conduction.

At the time, scientists understood very little about how human hearing works. But despite the fact that his ears left him, he could still hear himself playing music by placing one end of a wooden stick onto his piano and clenching on the other end with his teeth. When notes were struck, the vibrations from the piano were transferred to his jaw, and from there directly to his inner ear. Miraculously, he could hear again! Bone conduction was born.

Sound is nothing more than acoustic vibration in the air. These juggling atoms vibrating at certain frequencies cause the eardrum to vibrate, which are transformed into a different kind of vibration that the cochlea, also known as the inner ear, can interpret. The cochlea then transmits the information about the sound to the brain via the auditory nerve where it is processed as hearing.

But there’s a second way that humans can hear besides air conduction. If the inner ear is directly exposed to acoustic vibration in the bones, then a person can still hear although the eardrum is bypassed. This is one of the reasons you can still hear your own voice if you plug your ears. It’s also how whales hear while diving deep in the ocean or how male elephants can listen for mating calls by stomping females several kilometers away.

Beethoven’s clever bone-conducting solution is used in some hearing devices today. A bone conducting hearing device, or BAHA, converts the sound picked up by its microphone into vibrations that are transmitted through the bones of the skull to the cochlea of the inner ear. Essentially, the bone conducting device fills the role of a defective eardrum.

Bone conduction hearing devices are also used by people with perfect hearing in certain applications. For instance, military headsets allow soldiers to hear orders relayed through a bone conduction device, sometimes integrated into the helmet, despite the background noise of enemy gunfire. Special bone conduction hearing devices also allow divers to both hear and talk underwater.

Beethoven’s final struggles with deafness

The way Beethoven dealt with his deafness is one of the great stories of humanity. The cause of his deafness, though, remains something of a mystery.

His diagnosis is made all the more challenging since he suffered from a plethora of other illnesses. The list includes chronic abdominal pain and diarrhea that might have been due to an inflammatory bowel disorder, depression, alcohol abuse, respiratory problems, joint pain, eye inflammation, and cirrhosis of the liver. 

This last item, a consequence of his prodigious drinking, may have ultimately killed Beethoven, who died in 1827. An autopsy showed signs of severe cirrhosis, but also dilatation of the auditory and other related nerves in the ear.

As a common custom of the time, a young musician by the name of Ferdinand Hiller snipped off a lock of hair from Beethoven’s head as a keepsake. The lock stayed in the Hiller family for nearly a century until it somehow made its way into the hands of a Danish physician called Kay Fremming. The physician is famous for saving thousands of Jews during the occupation of Denmark by Nazi forces by helping them escape to Sweden, whose border was closeby to a tiny fishing village Fremming called home. Some speculate that one of the Jewish refugees gave Dr. Freeming the lock of Beethoven’s hair in gratitude for saving their lives.

What we know for sure is that the lock of hair, consisting of 582 strands, was passed down to Fremming’s daughter, who put it up for auction in 1994. It was purchased by Alfredo Guevara, an Arizona urologist, for a modest $7,000. Guevara kept a few strands and donated the rest to the Ira F. Brilliant Center for Beethoven Studies at San Jose State University in California.

At this point, scientists at the university thought of examining DNA from the great composer’s hair in order to look for clues as to how Beethoven became deaf.

The hair was put through a barrage of DNA, chemical, forensic, and toxicology tests. What immediately stood out was an abnormally high level of lead. During Beethoven’s time, people weren’t aware of lead poisoning and it was quite common to use plates for food and goblets for drinking made out of the toxic metal. Even the wine of that era, Beethoven’s favorite drink, often contained lead as a sweetener. This severe lead poisoning may have contributed to the composer’s lost hearing.

For a long time, Beethoven tried to conceal his deteriorating hearing, fearing that this may ruin his career if the word was out. But he couldn’t keep it up for too long. It was common for composers to also conduct and even perform their own music, and Beethoven’s condition eventually became noticeable. After watching one of Beethoven’s piano rehearsals in 1814, fellow composer Louis Spohr said “…the music was unintelligible unless one could look into the pianoforte part. I was deeply saddened at so hard a fate.”

At age 45, Beethoven’s hearing was completely gone, and so was his public life. In the final stretch of his life, the German composer became a reclusive, insular person who allowed only a select few friends to visit him. The music he composed during this time, which includes the famous Sixth Symphony, reflects Beethoven’s love for nature and his life in total silence in the countryside. Describing the Sixth Symphony, Beethoven said it is “more the expression of feeling than painting”, a point underlined by the title of the first movement. While completely deaf, Beethoven also composed Missa Solemnis, the solemn mass for orchestra and vocalists, and the opera Fidelio, among other major works.

It’s not clear if Beethoven’s inner ear was still functional in his later days so that he could continue using his bone-conducting stick to hear his compositions on the piano. Many experts believe he didn’t need to hear his pieces anyway since he was a master composer who knew all the rules of how music is made. Even in deafness, Beethoven was an unparalleled master of the language of music and an inspiration for resilience.

Changes in the brain that contribute to age-related hearing loss

Generally, as we age, our hearing deteriorates. Around one in three people between the ages of 65 and 74 have hearing loss, increasing to 50% from the age of 75 upwards.

A percentage of sufferers will experience loss through links to other contributory health factors such as diabetes or high blood pressure. Others will have experienced hearing trauma, either instantly due to a noise above 140dB or at a lower volume over a sustained period. Illness and injury may also be factors for some sufferers, who may then need assistance. A hearing aid from Hidden Hearing or other similar company may become a significant part of the user’s life, allowing him or her to live life relatively normally.

These various causes have been well understood for some time, but what is less-understood is the connection between the brain and the inner ear. We know more of the process of sound travelling by the outer ear, to the inner ear, where it is then converted into a signal for the brain to decode.

We also know that there’s a mass of data suggesting that hearing loss is deleterious to the brain. For example, John Hopkins University reported that the normal brain shrinkage associated with ageing is accelerated in those with hearing loss. In a long-term study showing brain changes over time, 126 participants were tracked over a decade to find evidence of brain changes, and those who had hearing impairment at the start of the study showed accelerated signs of brain atrophy compared to those with normal hearing. Because of the long term nature of the study it eliminated the possibility that the brain structures were damaged before hearing loss occurred.

But what about the ‘other direction’? It’s believed that the brain can tell the ear to make adjustments so that it’s easier to discriminate sounds in a noisy environment, via a set of nerves. A postgraduate study at MRC Leicester has attempted to see what happens to these nerves as aging progresses. It will examine whether change occurs, and if so, whether these changes could actually affect how the nerves deal with damage externally. In other words, could damage to the overall control system between the ear and the brain occur from two directions?

Image via Skidmore.

The results from the study do not seem to have been processed, but whatever comes of it, clearly more research into the effect of aging on the brain will need to be done. If it proves difficult to differentiate the two ‘directions’ – in other words, whether does brain atrophy causes hearing loss, or vice versa, or both – then a greater understanding of all parts of the auditory system will surely be necessary.

And it could be vital, because not only does hearing loss affect the elderly physically, but also socially and emotionally. It may perhaps preclude them from not being able to speak to relatives on the telephone, and deter them from leaving their home or meeting others. Hearing loss has also been linked to depression, social isolation, paranoia and Alzheimer’s Disease. And with the world’s elderly population increasing year on year the research is more vital than ever.

This device could let deaf people “hear” via their tongues

Out of all the solutions which could help deaf people here, this is definitely one of the most creative things I’ve seen. Researchers from the US have developed an electric mouthpiece that can transmit sounds to people – through their tongues.

The device is also cheap, widely effective, and very little invasive. The device uses a Bluetooth-enabled earpiece to pick up sounds, then converts them into electrical signals, and then convert them into vibrations which the users can hear by pushing their tongues up.

The mechanism is fairly similar to how current cochlear implants work, except you don’t need any surgery to implement it. The new mouthpiece also doesn’t require a patient’s auditory nerve to be functional, so it can be used by virtually all people suffering from deafness or similar related issues.

“It’s much simpler than undergoing surgery and we think it will be a lot less expensive than cochlear implants,” said John Williams, a mechanical engineer from Colorado State University, who co-led the project, in a press release. Cochlear implants are very effective and have transformed many lives, but not everyone is a candidate. We think our device will be just as effective but will work for many more people and cost less.”

The only downside is that this technology requires some training from the user, but that shouldn’t be much of a problem. They chose the tongue because the tongue is a very powerful muscle with thousands of nerves which can be used.

For this to work, people would have to be taught something like a whole new language, but it’s not especially difficult, and he explains how people could be taught this new language in the video below. This means that people can be taught to translate vibrations on their tongue into words – effectively allowing them to hear. Unfortunately, it will take a long time before this technology can be used by the public, but the prototypes are already ready.

So, what do you think about this? Is it innovative and can help numerous people, or is it just too quirky to work?

Images via Science Alert.

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Songbirds inspire next generation hearing aid, faithful to the human ear

Hearing loss can be devastating: you lose friends, become ever trapped inside your head and alienated from society. Yet, only one in five Americans choose to use a hearing aid. Some ignore their problem, others can’t afford treatment or installing a hearing aid, but really a lot of people choose not to wear a hearing aid because it can be just too unbearable. This might change for the better in the future, though. For instance, scientists at University of California are developing a next-generation hearing aid inspired by songbirds that emulates the human ear as realistically as possible.

Was that a chip or a chirp?

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Image credits: Virginia Green (http://virginiagreene.tumblr.com/)

All hearing aids have the same basic parts: a microphone, the tonehook or earhook, the volume control, the on/off switch and the battery door. The microphone picks up sounds and sends them to an amplifier that makes them louder. The hearing aid will make some pitches of sound louder than others, depending on the shape of the hearing loss. But Hearing aids aren’t effective for everyone. Hair cells in the inner ear must pick up the vibrations that the hearing aid sends and convert those vibrations into nerve signals. So, you need to have at least some hair cells in the inner ear for it to work. Moreover, most devices aren’t that well tuned, so must of your environment gets equally amplified – this can drive anyone crazy.

“In a crowded place, it can be very difficult to follow a conversation even if you don’t have hearing deficits,” says UC Berkeley neuroscientist Frederic Theunissen. “That situation can be terrible for a person wearing a hearing aid, which amplifies everything.”

Image your sitting in a crowded bar, at a table with your friends. Despite the racket and rattle around, you have no problem having a conversation with your friends because the human brain and ear work together beautifully to hone in on a particular signal – the rest is just background noise that isn’t processed consciously. With a hearing aid, this sort of differentiation is very difficult. So, the ultimate goal is to build a hearing aid that transmits signals and processes audio much in the way the brain would.

[ALSO SEE] Hearing restored in mice following hair cell regeneration therapy

Humans aren’t the only ones capable of differentiating between audio signals. Among other animals that are very apt at this is the songbird. For the past two years, Theunissen and colleagues have analyzed the brain imagery of songbirds to understand how these can distinguish between the chirp of a mate from dozens if not hundreds of strangers. The team eventually identified the exact neurons involved in this process which tune into a signal and remain tuned indifferent of how noisy the environment is. Theunissen calls this an “auditory spotlight”. Imagine you’re looking for your car keys on the dinner table. You have this particular shape, texture and colour that you’re searching for among plates, breadcrumbs and cats. In a similar way to the eye, the ear searchers and finds particular pitches and frequencies – say the voice of your friends at the bar.

“Our brain does all this work, suppressing echoes and background noise, conducting auditory scene analysis,” Theunissen says.

The “auditory spotlight” process has been reproduced in an algorithm, and now the UC team is working with a company to test whether the company can improve performance if installed on conventional hearing aids. This next generation of hearing aids will detect the features of the signal and separate it from any background noise. Unlike a traditional hearing aid, it will have a variable gain so that signal sounds get a boost without distortion, while background sounds are attenuated without being completely muffled out.

“This hearing aid should not eliminate all of the noise or distort the signal,” Theunissen says. “That wouldn’t sound real, and the real sound is the most pleasant and the one that we want to hear.”