Noise Induced Hearing Loss

Noise Induced Hearing Loss

There are two main hearing problem outcomes due to being in combat: noise-induced hearing loss and tinnitus. Noise induced hearing loss (NIHL) is caused due to extreme exposure to loud noises.This is a side effect of a sensorineural hearing loss, which is a lifelong impairment. High frequency noises can often distort human speech even though it can be heard. Sometimes it is difficult detecting the difference between words that sound similar. You may have a feeling of "fullness" in your ears after leaving a noisy environment. Ways you may develop a NIHL is from shooting firearms, explosions, aircraft engines, etc. Tinnitus is commonly known as "ringing of the ears" and heard differently by others. It is a symptom of the problem. The NIHL may not be the only problem in this case. It could also be a brain injury, brain tumor, medication, middle ear disease, and can occur with or without a hearing loss. There was 75,000 cases of auditory impairments among new recipients of VA compensation in 2003.

With this being said, please take into consideration the following information on prevention. NIHL is almost completely preventable. People can vary in their susceptibility to hearing loss. While research has shown some trends, there currently is no way to tell which individuals may be more susceptible than others. Different types of hearing protection  include: wearing earplugs or earmuffs, avoid loud environments, if possible, keep volume down on electronics, and to let ears rest after loud environments.

Thank you for reading our blog on the hearing process and how to protect and serve your ears! Thank you for your service to our country!

Resources for additional information can be found at the following links:
AARP
Jefferson University
Hearing Center of Excellence
Mayo Clinic Health
Veterans Health
Institute of Medicine
News21
Better Hearing Institute

Assistive Listening Devices

Hearing aids don’t work perfectly when there is background noise, distance, or echoes.  ALD (Assisted Listening Devices) can help. 

Loop Systems

Loop Systems amplify speech sounds and reduce background noises for people that use hearing aids or cochlear implants.  They are thin loops of wire that encircle a room.  Loop systems are very popular in Europe and can be found in buses, public auditoriums, churches, and other public buildings. Pros: reduced risk of acoustic feedback and an improved signal to noise ratio, easy to use with no pairing required, and a lower cost. Cons: not designed for music, telecoil orientation must be in a certain place in order to reduce feedback, requires installation, and digital devices can interfere with the signal.

FM Systems

FM systems are like mini radios and they can be used in classrooms, noisy restaurants, senior centers, or anywhere else where background noise makes it hard to listen to one speaker.  They work by having the speaker wear a microphone. The listener connects the FM receiver to their hearing aid or cochlear implant. Pros: FM radio waves have a good reception, installation is easy, and people without hearing aids can wear a receiver/headset. Cons: not a secure signal, must be tuned to the proper frequency at each location, draws attention, sound leakage, not directly compatible with hearing aids.

Infrared Systems

This is a device similar to an FM unit, but it uses infrared signals to transmit sound instead of radio signals. Pros: covers a large area, easy to install, secure transmission, people without hearing aids can wear receiver/headset. Cons: not directly compatible with hearing aids, need direct line of sight from the transmitter to the receiver, and in larger rooms multiple receivers, needs to be recharged regularly, and receiver needs to be tuned to the same frequency as the transmitter.

Personal amplifiers

Personal amplifiers are handy when Loop or FM systems are unavailable.  You can also use them at the theater, while traveling, being outdoors, or watching TV.  They are small and increase sound levels and reduce background noise. Some have microphones that move toward a speaker or another sound source. Pros: reduces background noise, available when other options are not, and clarifies and amplifies sound. Cons: not always directly compatible with hearing aids and may need to be recharged often.

These are options that are readily available for you if you have difficulties with hearing. 

Additional Hearing Devices

BAHA- Bone Anchored Hearing Aid

The BAHA is an additional hearing aid that is beneficial for individuals who have a conductive hearing loss and do not receive benefit from regular hearing aids. It is bone- anchored, which means that it stimulates the bone behind your ear (mastoid).

Cochlear Implant

A cochlear implant is a device that involves a surgical procedure. This is for severe or profound hearing loss and people who do not benefit from hearing aids. It is usually an outpatient surgery with little risk. Once a cochlear implant is placed normal hearing cannot be restored as it connects with the auditory nerve.

Noise-induced hearing loss would not benefit from these two options. However, if you have a conductive hearing loss, these may be something to consider. Also note that cochlear implants are useful for severe and profound sensorineural hearing loss as well.

Hearing Aids

 

Behind the Ear (BTE)

 

 

All parts of the hearing aid are located behind the ear. It is one of the largest devices, but is very reliable. It can be used for a mild to profound hearing loss. Pros: easy to manipulate due to size, lasts longer, directional microphones, volume control. Cons: visible and awkward for phone use. Cost: $1,580-2,769

 

 

Receiver in the Canal (RIC)

Most of the components are behind the ear, except for receiver, which is the part that allows sound to enter the ear. This works well for a mild to severe hearing loss. Pros: Leaves the canal open to allow more natural sound. Cons: harder to use with phone. Cost: $1,694-2,993

 

• In-the-Ear (ITE)
• This device fits completely within the outer ear. It does not fit completely in the ear canal, however. Each one includes an individualized ear mold for comfort. It is for mild to severe hearing losses. Pros: volume control, directional microphones, and easy to use with a phone. Cons: conspicuous. Cost: $1,600-2,757

 

In the Canal (ITC)

 This one is partially in the canal and is smaller than the ITE, which also contains an individualized ear mold. This hearing device is for mild to sever hearing loss. Pros:  directional microphones, volume control, and not very visible. Cons: feedback/extra noise. Cost: $1,716-2,681

 

 

Completely in the Canal (CIC)

This hearing aid fits completely within the ear canal. It also contains an individualized ear mold and is used for mild to moderate hearing loss. Pros: enhanced telephone use, easy to use, ear helps localize sounds, not visible. Cons: no directional microphones, feedback, no volume control or on/off switch and high maintenance care. Cost: $1,695-2,958

 

 

Invisible in the Canal (IIC)

This is the smallest hearing aid available and is for moderate to severe hearing loss. Pros;  easy to use, invisible, allows natural sound, no feedback. Cons: hard to change batteries, short battery life, high maintenance for cleaning. Cost: $1,695-2,958

 

Types of Hearing Loss

 

There are three types of hearing loss. These include: Sensorineural, Conductive, and Mixed.

Sensorineural:

The most common types of sensorineural hearing loss are caused by aging and loud noises. For you, the most common type would be noise-induced. For example, gun shots, jet engines, vehicles, etc. This is a gradual hearing loss that will result over a long period of time. It is a disturbance in the inner ear. It is not medically or surgically corrected.

Conductive:

This can be caused by excessive ear wax build up over time, ear infections, or hereditary causes. A conductive hearing loss may be temporary. It can be treated by medical treatment or the passage of time. This is an issue within the outer or middle ear. It is important to note, that noise may also damage the ear drum, causing a conductive hearing loss, rather than sensorineural.

Mixed:

A mixed hearing loss is essentially when an individual has both a conductive and sensorineural hearing loss.

Here is an audiogram visual for the levels of severity corresponding to the different types of hearing loss.



How do we hear?

 

In order to understand hearing loss, you need to understand the basics of the hearing process. Sound is funneled into the outer ear. Here it enters the ear canal, which leads the sound to the ear drum. The ear drum vibrates causing small bones in our ears to move. Through this movement a snail-shaped structure picks up the vibrations signaling to our brain what we are hearing.