Waking up to the sound of birds chirping in the yard, hearing the soft breathing of your baby, or even hearing the sound of your own name are things that most of us take for granted on a daily basis. To those with hearing loss, these simple moments can be a far-away and unattainable dream. But a truly remarkable, non-surgical technology has been developed that can allow many deaf and hard of hearing people to enjoy hearing voices, ambient sounds and even music.
What Was the Inspiration Behind Bone Conduction Hearing Aids?
What inspired such a life-changing invention, you might ask? Ludwig Van Beethoven was born in the year 1770. Very early on he took a great interest in music in general, but most of all in composing great sonatas and symphonies. He published his first work before he was 12 years old. His love for and knowledge of music continued to develop and grow stronger. Composing concertos and variations on existing themes gained him great notoriety until at age 26 he began to notice random noises and buzzing sounds in his ears. By the end of his 29th year, Beethoven had lost 60 percent of his ability to hear. He was devastated, to say the least.
Over the next five years, his hearing continued to diminish until, at the age of 34, he was completely deaf. He continued to write because he could hear the music in his mind but so desperately wanted to hear his compositions come to life. Realizing that sound creates vibrations, which bypass the eardrums altogether (thus he could hear his own voice), he experimented with ways to conduct the vibrations to his eardrums. He was successful to a degree with hearing the sounds of his piano by way of a rod; attaching one end to the top of the piano and the other end, he leaned his jawbone on. By this method, Beethoven was able to “hear” his music and even went on to write his first Symphony at the age of 50.
How Were Bone Conductive Headphones Developed?
This simple contraption has sparked years of experimentation and refinement and years of trying different types of devices to allow the deaf to hear. Compressing the skin against the bone seemed to help, but the skin could become irritated or bruised, and it was very uncomfortable. A primitive headband attached to a pair of eyeglasses was found to dampen the higher frequency sounds somewhat, and when spread out over a greater area, the skin appeared to absorb much of the vibration, minimizing the sounds at the cochlea.
Dental Implants for the deaf were tried in the 1960s, and it was somewhat more successful than other things that had been tried, likely because, just like Beethoven, it involved the jawbone. A decade later a small device was anchored right into the skull with titanium screws. It did not require the skin pressure that some of the other methods did and was able to carry the vibrations directly to the bone via the screw, without the dampening qualities of the skin. Today this is referred to as a Bone Anchored Hearing Aid (BAHA), and many thousands of hearing-impaired people have had a measure of success hearing while using this device. It did cause some skin issues and bone loss, and it was less than attractive to the eye.
A smaller version became available that was held in place by magnetic force. A magnet would be implanted directly into the skull, behind and to the rear of the ear. The small device with another strong magnet attached was then placed over the implant. The magnetic attraction held it in position, but the skin compression from the magnetic force was rather painful, and there were some issues with powering the device.
From these studies came the idea of a “skin drive” or a non-implanted, non-invasive solution in which the vibrations are conducted through the person’s skin itself. A magnet is still used, but this time it is inside the device. This took the form of an over-the-head band, or as extensions of the earpiece of a pair of eyeglasses. The headband version seemed to be more comfortable, and because it is built on a steel spring, it stays in place by tension. It was very successful, but still had a lower threshold of sound transmission than they hoped for. Today, refinements have made, and bone conduction headphones are one of the top choices for those with hearing loss.
Who Can Benefit Most From This Technology?
While there may be certain causes of deafness that would preclude someone from being helped by using bone conduction headphones, many others will find a significant improvement by putting them to use.
People who suffer from difficult skin problems in and around the ear that might prevent the insertion of a traditional hearing aid are able to enjoy some recovery of their hearing with bone conduction headphones. Psoriasis and eczema are two examples of this. The apparatus is worn across the top or around the back of the head and rests against your cheekbones, steering clear of the delicate skin of the inner ear.
Chronic ear disease, which causes excessive drainage of the ear canal can be messy and can interfere with the function of standard hearing aids. This fluid can be a cause of deafness as the fluid blocks sound from reaching the eardrum. Bone conduction devices send the vibrations directly to the cochlea and on to the brain where they are translated into sounds you can recognize.
What Are the Advantages of Bone Conduction Headphones?
Are these hearing devices any better than a traditional hearing aid? That depends somewhat on the cause of the hearing loss and the health of the inner ear, but there are a few definite advantages.
Safer and Less Stressful on Your Ears
Your ears are a very delicately designed part of your body. A series of tiny curves, membranes and other things go into making the ear work. You must be careful not to damage your eardrum by the excessive vibration caused by loud music or sounds, such as shotgun blasts or doors slamming. Protecting your eardrum is the main reason you are told not to put a cotton swab inside your ear. Once the eardrum is damaged to some degree, you may hear a smaller range of notes and sounds, and softer, more muted sounds may fade from your hearing as well. Bone conduction hearing aids bypass the eardrum, so it is much safer for long periods of listening or at higher volumes.
A Greater Range of Sound
Those elusive high notes may be easier to hear, as well as softer, quieter sounds. This is because they are the tenor sounds – they have very shallow and rapid vibration patterns that can escape even those without serious hearing difficulty. The lower, bass tones have deep, booming vibrations and can be felt even before they are heard. (Think about the teenager next door – you can feel the boom-boom of his radio before he even turns down your street.) That is why lower tones are easier to hear.
Bypass Damaged Eardrums
If your eardrums have been damaged, either by illness or physical injury, your hearing may be deeply impaired, depending on the extent of the damage. In normal hearing, sounds bounce off the eardrum and are picked up by the cochlea, which in turn, passes them on to the brain so you can interpret them as a warning or as something safe and enjoyable. When the eardrum is damaged, this makes hearing sounds impossible. Bone conduction headphones bypass the eardrum altogether. Vibrations are transmitted directly to the cochlea, and the brain is then able to complete its job, as it should.
Not Only for the Deaf
While bone conduction devices allow the hearing impaired to pick up some ambient sounds and human voices, the technology has also benefited those with perfect hearing. The devices are somewhat different than the ones designed for those with hearing loss and can be plugged into a multitude of electronic gadgets. These hi-fidelity headphones with stereo sound can be worn by anyone. Instead of the earbuds or covers found in most stereo headphones, there are pads which rest on the back of the cheekbone near the ear and transmit the sound from there to the cochlea, which processes vibrations into sound as previously described.
The real benefit to the hearing comes from reducing the stress and damage caused by hour after hour of loud music, movies and video games bombarding delicate eardrums. This reduces the strain on the eardrum and still allows the person to enjoy their entertainment thoroughly. Another big plus is the fact that no one else will be bothered by having to listen to the sound pollution caused by the high volumes. Since it is all vibration, there is no sound unless you are the one wearing the device.
Bone conduction headphones for the deaf have reached an astounding level of refinement. They are easy to take off and put on and allow many people to feel like an integral part of the world again. If you are struggling with your hearing, it may be worth investigating this solution. Will you hear every sound? Will things sound completely normal? It is hard to say, but for those suffering from hearing loss, every sound that allows them to better communicate with the world around them will be magical.