Hearing Loss
Significant hearing loss affects patients of all ages. With nearly 20 doctoral level audiologists at multiple locations, the Henry Ford Division of Audiology is dedicated to helping people with hearing loss improve their quality of life.
Types of hearing loss
Conductive hearing loss
Conductive hearing loss occurs when sound is not conducted efficiently through the outer ear canal to the middle ear. Conductive hearing loss usually involves a reduction in sound level, or the volume of sounds. This type of hearing loss can often be medically or surgically corrected.
Examples of conditions that may cause a conductive hearing loss include:
- Absence or malformation of the outer or middle ear
- Fluid in the middle ear from colds, allergies, poor eustachian tube function, ear infection (otitis media), perforated eardrum or benign tumors
- Impacted earwax
- Infection in the ear canal (external otitis)
- Presence of a foreign body
Sensorineural hearing loss
Sensorineural hearing loss is the most common type of hearing loss addressed by the use of hearing aids. It involves not necessarily a reduction in the volume of sound, but a reduction in the ability to hear higher pitched sounds, including consonants in speech. It also affects speech understanding, specifically the ability to hear clearly.
Sensorineural hearing loss occurs when there is damage to the inner ear (cochlea) or to the nerve pathways from the inner ear to the brain. Typically, it cannot be medically or surgically corrected.
Possible causes of sensorineural hearing loss include:
- Aging
- Diseases
- Drugs that are toxic to the auditory system
- Genetic syndromes
- Head Trauma
- Noise exposure
- Problems at birth
- Tumors
- Viruses
For a sample of what life is like with sensorineural hearing loss, check out Henry Ford’s Hearing Loss Simulator.
Degree of hearing loss
Sound levels are measured in decibels (dB). Decibels are like the degrees of a thermometer. As temperature increases, so does the number of degrees. As the volume of sound increases, so does the number of decibels.
Degree of hearing loss refers to the severity of the loss. The levels correspond to the patient's thresholds, or the softest intensity at which a sound is perceived.
- Normal Hearing (0-15 dB)
- Minimal Hearing Loss (16-24 dB)
- Mild Hearing Loss (25-40 dB)
- Moderate Hearing Loss (41-55 dB)
- Moderately-Severe Hearing Loss (56-69 dB)
- Severe Hearing Loss (70-89 dB)
- Profound Hearing Loss (90+ dB)
Examples of decibel levels in everyday life
Sound | Noise level (dB) | Effect |
---|---|---|
Jet Engines | 140 | Threshold of pain usually begins around 125dB |
Shotgun Firing | 130 |
Same as above. |
Rock Concerts | 120 | Same as above. |
Thunderclap | 120 | |
Power Saw | 110 |
Same as above. |
Jackhammer | 110 |
Same as above. |
Snowmobile | 105 | Same as above. |
Garbage Truck/Cement Mixer | 100 | No more than 15 minutes of unprotected exposure recommended for sounds between 90-100 dB. 85 dB is the level at which hearing damage begins after 8 hours of continuous exposure, Comfortable hearing levels are under 60 dB. |
Farm Tractor | 98 | Same as above. |
Motorcycle | 88 | Same as above. |
Lawnmower | 85-90 | Same as above. |
Diesel Truck | 84 | 85dB is the level at which hearing damage begins after 8 hours of continuous exposure. Comfortable hearing levels are under 60 dB. |
Average City Traffic | 80 |
Same as above. |
Washing Machine | 78 |
Same as above. |
Hair Dryer/Vacuum Cleaner | 70 |
Same as above. |
Normal Conversation | 50-65 |
Same as above. |
Refrigerator Humming | 40 | Just Audible. |
Whisper | 30 |
Same as above. |
Rustling Leaves | 20 |
Same as above. |
Normal Breathing | 10 |
Same as above. |
Source: National Institute on Deafness and other Communication Disorders (NIDCD) |