Hearing Loss – Understanding What it is & What to Expect
The ability to hear is often taken for granted by many, so understandably when hearing loss occurs it can have large implications on people’s lives. Many people with hearing loss may find themselves struggling emotionally and can often become depressed or withdrawn. Other strong emotions like embarrassment can also lead to denial and prevent people from seeking professional help.
Hearing loss has a range. Some people who experience it might be able to hear certain noises, while others might not be able to hear at all. Hearing loss can also be progressive by starting slow, or it can also affect some since they are born.
One of the first factors in coping with hearing loss is understanding the complexities of what hearing loss is, your specific type, and the available treatment. Keep reading to learn the basics of everything related to hearing loss.
The Science of Hearing
The auditory system oversees the process of how we hear and understand sounds from our environment. This system is comprised of both peripheral components like the outer, middle, and inner ear, as well as certain brain regions such as the auditory cortex.
Sounds are created by energy waves, and these waves then travel through different mediums by moving molecules which creates an increase or decrease in the pressure of air. The number of periods within a specified amount of time is the frequency of the sound in Hertz (Hz). The typical frequency for human hearing is between 20-20,000 Hertz.
Read our past blog Learn the Science of Hearing, for more information on this.
The Journey Sound Takes
Sound waves start from an external source and then enter the outer ear and travel through the narrow passageway called the ear canal. The eardrum then vibrates from the sound waves and these vibrations travel to three small bones (malleus, incus, and stapes) found in the middle ear. Then these bones in the middle amplify the sound vibrations before being sent to the inner ear.
While the sound waves are in the inner ear, they travel to the snail-shaped structure called the fluid-filled cochlea. The vibrations then cause the fluid in the cochlea to ripple, which creates small waves, that hair cells inside the cochlea detect. As these hair cells move up and down with the motion of the waves, chemicals are released into the cells and an electrical signal is created.
Finally, the auditory nerve carries these electrical signals to the brain, which turns the sound into something we recognize and understand.
What is Hearing Loss?
According to the World Health Organization, estimates show that by the year 2050, 2.5 billion people to have some level of hearing loss. Currently, 5% of the population or around 430 million people, have what is considered disabling hearing loss, referring to those with a loss greater than 35 decibels.
Decibels (dB) are used to describe the intensity of sound. The scale starts at 0 decibels, which is the faintest sound human ears can detect. And goes to over 180 decibels, which is the noise level at a rocket pad when launching is taking place.
Decibels increase by units of 10. At each increase, the intensity of the noise is becoming 10x that of the previous increment. So, while 20 decibels is 10x the intensity of 10, 30 decibels is actually 100x more intense than 10.
Sounds greater than 85 decibels are considered potentially dangerous, depending on the duration and proximity to the sound. For this level ear protection should be used during extended exposure. The following image gives examples of sounds with their approximate level of decibels.
Hearing loss is often categorized in these three ways:
- Conductive – involving the outer or middle ear
- This type of hearing loss happens when sound cannot travel through the outer and middle ear. It typically may be hard to hear soft sounds, and louder noise might be muffled. This type of hearing loss is usually temporary and can often be fixed with medicine or surgery.
- There are many causes of conductive hearing loss, including fluid in the middle ear (often from colds or allergies), ear infections, a hole in the eardrum, ear wax stuck in the ear canal, ear infections, an object in the outer ear, or a deformity of the outer or middle ear.
- Sensorineural (SNHL) – involving the inner ear
- This type of hearing loss is the result of inner ear damage, or when problems occur with the nerve pathways from the inner ear to the brain. Soft sounds may be hard to hear, and louder sounds may sound muffled or unclear. SNHL is the most common type of permanent hearing loss. Hearing treatment will not include medicine and surgery but hearing aids may be able to.Sensorineural (SNHL) – involving the inner ear
- SNHL can be caused by: illnesses, hereditary hearing loss, aging, being hit in the head, deformity of the inner ear, and loud noises or explosions.
- Sometimes the cause of sensorineural hearing loss can be from damage to the hair cells found in the inner ear. It is important to remember that it is not possible to correct any damage done to these hair cells. Preventative measures can be taken to protect the hair cells of the inner ear, such as wearing earplugs when attending a concert, or mowing the lawn.
- Mixed – a combination of the two
- Mixed hearing loss is when both conductive hearing loss and sensorineural hearing loss occur at the same time. This means that there may be damage to the outer or middle ear as well as in the inner ear.
- Mixed hearing loss is caused by anything that would cause either sensorineural or conductive hearing loss. For example, having Sensorineural hearing loss because of hereditary causes, while also having conductive hearing loss because of an ear infection.
- Many audiologists recommend treating the conductive hearing loss issues first. This way there is a better understanding of the severity of the sensorineural hearing loss. Using the previous example, hearing treatment would start by alleviating the ear infection and then assessing the sensorineural hearing loss through testing.
If you are experiencing hearing loss, it’s important to have a hearing test to determine the type and cause of hearing loss.
Understanding an Audiogram
Audiograms are graphs used by audiologists to showcase the results of your hearing test. They are then used to help understand the complexity and severity of hearing loss. The purpose of the audiogram is to test the hearing ability in each ear, across a large range of frequencies. Audiograms plot the hearing thresholds, or the softest sound able to be detected 50% of the time, across various frequencies or pitches.
Hearing loss can leThe audiogram has two axes. The horizontal or x-axis represents the frequency or pitch from lowest to highest (typically 250-8000 Hertz). Put simply, the sounds get higher pitched as you read the graph left to right. The vertical or y-axis on the audiogram represents the intensity or loudness of the sound in decibels.
Audiograms are read with the lowest level at the top of the chart and the highest level at the bottom. The chart typically starts with 0 decibels, which represents the softest level of sound the average person with normal hearing will be able to hear at any frequency.
There are also a few symbols found on the audiogram that depend on the type of testing. With air conduction testing, headphones will be used so that the sound will be traveling through the air in the ear canal. This specific type of testing uses a red “O” for the right earmarks and a blue “X” for the left ear on the audiogram. With bone conduction testing, a device is used behind the ear to transmit sound through the vibration of the mastoid bone, and it often uses a “[“ or “<” as symbols.
The audiologist or hearing professional uses the audiogram to determine the severity of the hearing loss depending on where the points are marked on the chart. The categories for severity are slight, mild, moderate, moderate-to-severe, and severe or profound.
Comorbidities Associated with Hearing Loss
Comorbidity is the simultaneous presence of two or more diseases or medical conditions. Unfortunately, hearing loss often comes with several mental and physical problems. The six major comorbidities associated with hearing loss include social isolation and loneliness, depression, falls, cardiovascular disease, diabetes, and cognitive impairment or dementia.
For more information, read our previous blog Hearing Loss and Associated Comorbidities: What Do We Know?
For some with hearing loss, hearing aids may be able to help. Hearing aids are battery-powered devices designed to improve hearing abilities and can be worn in or behind the ear. These devices use a microphone to pick up sounds in the environment. an amplifier to make the sounds louder and a receiver to send the amplified sounds to the ear. But as mentioned earlier, hearing aids are not able to solve all hearing loss problems.
There are two types of hearing aids, analog and digital. Analog hearing aids are used to convert sound waves into electrical signals and then make them louder. Digital hearing aids are used to convert sound waves into codes and then amplify these.
Hearing aids also come in three main styles: canal, in-the-ear (ITE), and behind-the-ear (BTE).
Canal hearing aids are made to fit inside the ear, either inside the canal (made to fit in each specific ear) or completely-in-canal which is smaller and more hidden. But because of their small size, canal hearing aids are not recommended for children or those who might have trouble with small devices.
In-the-ear hearing aids fit completely inside your outer ear and have a hard plastic case that holds the electronic components. These work best for mild to severe hearing loss, but they also are not recommended for children because their ears are still growing.
Behind-the-ear hearing aids sit behind your ear as the name suggests and has an earmold that fits inside the outer ear.
When first getting hearing aids, it might take time to get used to them. With progressive hearing loss, it’s important to remember that even with hearing aids, your hearing will not improve to its original state.
It’s also important to remember that taking care of your hearing aids will prolong their life. Remember to protect hearing aids from heat, moisture, children, and pets. You should clean them as directed and turn them off when not in use. And it’s essential to replace dead batteries immediately. Generally, hearing aids can last for between three and six years, but a new pair might be needed sooner if hearing worsens.
Stay tuned for next week’s blog to learn ways to cope with hearing loss.
If you have experienced trouble hearing or are looking for an audiologist to conduct a hearing screening, please call our office today at 737-279-1340.
AnyPlace Audiology offers comprehensive hearing health care. Our team helps you understand your condition and explore all available possibilities so that you can feel comfortable with your hearing health decisions.
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