Dr. Kevin Most: Hearing loss
We often take our 5 senses for granted, we really do not even think about them or appreciate how they work or how they impact our life. These senses allow us to taste our food, to see the beauty of a sunset and even something as simple as listening to this radio show. We have talked about how amazing the brain and body really is but we have never touched on our sense of hearing.
Last week we briefly discussed the woman in China who cannot hear men’s voices due to a very rare condition. We laughed about it as it does set one up for a humorous situation story, but any hearing loss can be devastating to the individual. Imagine that woman never being able to hear her husband’s voice again and the husband not being able to verbally communicate with his wife. What is probably more important is the 30- 40 million Americans who suffer from some degree of hearing loss.
As this is a radio program I thought we would discuss hearing, how it works, what makes us lose our hearing, what can be done about hearing loss and a few odds and ends. Most states require the testing of hearing within the first 48 hours of life, allowing physicians to identify infants early in life so interventions can be made that will improve the social and cognitive advancement of the baby. If you want to see the impact of hearing, google “baby hears for the first time”, it will make you smile, perhaps cry and more importantly make you feel blessed that you have this sense that we take for granted.
Although we all think about our ears as the portion of skin and cartilage we see on the side of our head, the most important parts are sitting within our skull. I am not saying the outer part of the ear is unimportant, on the contrary the outer portion is very important as is our ear canal, both allow us to have sounds captured and put to the inner ear where it is converted into electric messages that are sent to the brain where it is converted into meaning. If you just stop and think about that, the inner ear has the ability to convert the outside sounds to electric activity which allows us to appreciate the sound.
So how does this work. Sounds are transported down the ear canal to our eardrum, those sounds make the ear drum vibrate, those subtle movements force pressure on a very small bone on the eardrum, which in turn moves 2 other small bones (including the smallest bone in the human body, the stapes). These movements transfer the vibrations to the inner ear portion called the cochlea. These vibrations move fluid in the cochlea over microscopically small hair cells. The hair cells then generate nerve impulses which travel to the auditory nerve and on to the brain, where it is converted into meaningful sound. All of this happens within a tiny fraction of a second and is ultimately what we “hear in our brain”. We have hearing loss when those tiny hair cells are damaged.
That is a simple description but hopefully you are all as amazed as I am on how this works. The ear is also responsible for our balance and the same equipment used for our hearing sends messages to our brain for our balance system. The social impact of hearing can also not be minimized, it allows us to communicate more easily, it provides us a safe felling and allows our learning process to accelerate.
What can you do to protect your hearing? Wearing hearing protection when you will be around loud noises is very important. Sound canceling or deadening headphones are very popular now as people try to eliminate unwanted noises as certain times. The technology behind these is amazing and it allows the option to filter noises so that music can be enjoyed at a much lower level comfortably. Often we will do the exact opposite, getting as close to the band and speakers when at a concert is probably not a great idea. Listening to music while cutting the grass is also not a great idea as the music is turned up loud enough to drown out the mower sound. We know that exposure to loud noises damages the fine hair cells in our ears necessary for hearing. This can be a one-time exposure to a very loud noise like a firecracker that blows off next to our ear to longer term exposure to loud noises often in a work setting.
So what is too loud? Research has shown that we can tolerate sounds that are less than 75 decibels for a long time and this would be very unlikely to cause hearing loss. Long or repeated exposure to sounds over 85 decibels can cause hearing loss. The louder the sound the shorter the amount of time it takes to cause hearing loss.
So what are the decibels to common noises we are exposed to.
Normal conversation – 60 decibels
Vacuum cleaner- 75 decibels
Heavy city traffic- 85 decibels
Lawn mower- 90 decibels
Motorcycle- 95 Decibels
Sporting events – 105 decibels
Jackhammer – 110 decibels
Music from phone at max volume – 110 decibels
Sirens- 120 decibels
Firecracker or firearms- 150 decibels
Hearing loss can be gradual or sudden, it can be simple or complex. Hearing loss may be caused by viruses, it may be caused by trauma and we know that our hearing decreases as we age. For example something as simple as using qtips can cause ear wax build up and cause gradual hearing loss which is totally reversible with irrigation of the ear canal, or it could be sudden from extended or sudden exposure to loud noises which damages the hair cells. Nerve or vascular injury in the brain can also cause hearing loss.
Research is being done now at Harvard that is looking at how can we repair or rebuild the hair cells that are damaged by noise exposure or viruses. In the meantime our treatment options are quite limited.
As we age many of us will have a decrease in our hearing, for some it is corrected by just turning up the sound, this amplifies the sound waves and allows for the movement in our ears and allows for continued hearing, now this is practical when you are alone watching a movie or listening to a radio, but when in a group this is not practical. In those cases a hearing aid may be needed. There have been many advances in hearing aids. In the past they were big and bulky with poor battery life, now they are much smaller and in many cases not even noticed. This is important as people feel very self-conscious when initially wearing a hearing aid. The technology has gone well beyond just the size and battery life. We now have hearing aids that are controlled with Bluetooth applications so volume control can be changed using an app, and they can be used as your earphones as well, meaning you can stream your music from your smartphone to your hearing aid. The advancements that have been made in hearing aids are remarkable, the ability for the devices to be connected from ear to ear allows for better sound quality as well as delivering better clarity of speech. Think of it this way, if one ear hears well and one does not hear as well the brain can be confused with the message as it is receiving 2 pieces of data from sources.
Hearing aids are not ”one size fits all” and many are custom made with molds, new technology has made some of the newer devices with soft silicone which eliminates the need for customized moldings and makes getting the aid quicker and easier. That being said the downside is that basic Medicare coverage will cover the cost of the hearing test but does not cover the cost of the hearing aid. Seniors who are looking at supplemental Medicare insurance plans should review and see if hearing aids are covered and if so are there limitations to brands. In Illinois the Humana Medicare Advantage plan added hearing aids to its coverage last year but not all plans or states have this coverage. This is not insignificant as the cost of hearing aids will cost thousands in most cases. This high cost is often a barrier to get the help and relief that hearing aids provide.
You may have heard of “cochlear implants” This is a technique that implants a small electronic device that does the work of a damaged cochlea. It is not a hearing aid per se, it is a device that allows for natural hearing by doing the work of a damaged inner ear. These are often needed in individuals with profound hearing loss in one ear, while having normal hearing in the other, although some will have bilateral cochlear implants which helps identify the direction of sound and separate sounds out. Hearing aids in these individuals often do little or no good as the issue is the damaged cochlea not volume. They are amazing pieces of technology that that has a sound processor placed behind the ear, this captures the sound and makes a digital code which sends this to the implant where it is converted into electrical impulses that stimulate the hearing nerve which sends those to the brain where they are interpreted as sound.
Individuals who have lost their hearing and have no option to replace the hearing with technology are at a disadvantage. If you know there is someone who is deaf in your conversation there are a few things each individual can do to make for more meaningful communication experience. Individuals who are deaf often are very adept at reading lips, so face the individual while you are in the conversation allowing them to see your lips move. Remember they are deaf and not blind so you don’t need to get close to them. Speak clearly, slow and steady, this allows the individual an opportunity to essentially “hear” you as they send the message to their brain of what you are saying. Try not to turn away from the individual while talking, everyone in the conversation should understand that, and setting that expectation to a group is very appropriate. Often repeating important portions of discussion is key, and having paper and a pen handy will often help.
Another thing to remember is not all deaf individuals are mute, many are able to speak but often may choose not to as they have difficulty with their regulating their volume , pitch or the sound of their voice. They may prefer to communicate with a written form.
Awareness of a deaf individual and communicating appropriately shows respect and dignity to this individual who is often blocked out of much of the normal communication.