Humans are exposed to all kinds of sounds on a daily basis; including cars, engines, televisions, or radios. Under most circumstances, these sounds are at safe levels and do not affect our hearing. However, when we are exposed to loud noises, sensitive structures inside the inner ear can be damaged. This condition is referred to as noise induced sensorineural hearing loss.
Hearing is a complex mechanism which requires several structures to work together. The outer ear includes the pinna and external auditory canal. The pinna functions to collect sound waves and direct them into the auditory canal. Because of its unique structure, sounds are amplified as they travel towards the back of the auditory canal. The captured sound waves then reach the tympanic membrane (eardrum) at the back of the canal, causing it to vibrate back and forth. The eardrum represents the separating barrier between the outer and the middle ear. As the eardrum vibrates, three tiny bones behind it begin to shift with it. These tiny bones are considered the smallest in the body, and are called ossicles. The last tiny bone, commonly referred to as the stapes, then transfers the vibrating motion to the organ of hearing, the cochlea. It is inside the cochlea where tiny structures called “hair cells” convert the vibrating energy into an electrical signal. The signal travels to the brain where perception occurs.
When noises are too loud, the tiny hair cells within the inner ear are damaged and eventually die. This results in decreased hearing. Noise induced hearing loss can be caused by a one-time exposure to an intense sound (such as a blast) or by continuous exposure to loud sounds over an extended period of time (working in a loud shop). Leisure activities can also put one at risk for noise induced hearing loss. This might include listening to MP3 players at high volumes or attending loud rock concerts.
There are many other causes of hearing loss besides noise, and these causes include aging (presbycusis), genetics, disease (history of recurrent middle ear infections, viral inner ear infections, and Meniere’s disease), and trauma .The severity of hearing loss depends on all of these factors , which can co-exist and be additive. Individuals with a mild hearing loss might only experience difficulty hearing with background noises. Individuals with a severe hearing loss may experience difficulty during normal conversation, which can impact their personal and professional life significantly. Another common symptom of hearing loss is ringing or buzzing in the ear, which is referred to as tinnitus. Tinnitus will often come and go, and can be extremely bothersome to patients. Machines that create masking sounds (white noise) can be used to “cancel-out” the tinnitus in many cases.
Noise induced hearing loss is the only type of hearing loss that can be completely prevented. The best way to do so is to avoid loud noises. If one cannot avoid excessive noise, hearing protection is recommended. Ear plugs or ear muffs are frequently used to help decrease loud noises.
Proper assessment of hearing loss requires a hearing evaluation. If one suspects that their hearing has decreased it is important to see an otolaryngologist (Ears, Nose, and Throat physician) or licensed hearing professional who can perform a specialized hearing test. Depending on the results and exam, a patient may be a candidate for a hearing aid or other assistive listening devices. Other modalities include fabricating a custom ear plug that can minimize additional noise exposure if one is routinely exposed to loud noises at work or during hobbies (i.e. musicians). If a patient wishes to pursue hearing aids, a hearing aid evaluation is set up. During a hearing aid evaluation a trained audiologist or hearing instrument specialist will meet with the patient and help them find a hearing aid model which works best for them.
If you have any questions about Noise Induced Hearing Loss or want to set up an evaluation with one of our Board Certified Ear Nose Throat specialists, or licensed audiologists or hearing instrument specialists, please contact us at Colden & Seymour Ear Nose Throat and Allergy at 978-997-1550, or through our website.