HEARING LOSS BASICS

Forms of Hearing Loss

Hearing loss is a broad term that encompasses several different impairments involving the structure of the ear. When many people hear terms such as "hearing loss" or "deaf", they assume this means a person is completely incapable of experiencing sound; in actuality, this is not necessarily the case.

Conductive vs. Sensorineural Hearing Loss

Conductive hearing loss is any condition that prevents sound from traveling properly through the ear canal or middle ear space. Patients with conductive hearing loss are typically fitted with behind-the-ear or bone-anchored hearing aids, depending on the specific cause of the hearing loss.

Sensorineural hearing loss is any condition that affects the sound-detecting nerves deep within the inner ear. Individuals with this type of hearing loss may be fitted for hearing aids, or receive cochlear implants, which bypass the cochlea and convert sound into electric signals sent straight into the nervous tissue.

Unilateral vs. Bilateral Hearing Loss

Hearing loss can be either bilateral or unilateral, referring to which ears are affected. Bilateral hearing loss means both ears are affected, while unilateral means the hearing loss is limited to one ear. Bilateral hearing loss is the more obvious of the two, and is typically more quickly diagnosed. It is not uncommon for unilateral hearing loss to go unnoticed and therefore undiagnosed for an extended period of time.

Levels of Hearing Loss

In terms of severity, hearing loss is usually measured in "db HL", and is categorized into one of six levels:

Normal...........................0-15 db HL

• The baseline for human hearing.

Slight.........................16 to 25 db HL

• The least severe form of hearing loss, many people in this range are unaware that they are even affected.

Mild...........................26 to 40 db HL

• Difficulty hearing soft speech and other similarly quiet sounds. Depending on the person, may or may not require hearing aids.

Moderate..................41 to 55 db HL

• Vowel sounds begin to get lost in this range. Typically requires some form of hearing aid to understand every-day speech.

Moderately Severe...........56 to 70 db HL

• Perception of speech is decreased greatly, and may not be decipherable even with hearing aids.

Severe........................71 to 90 db HL

• Without some form of amplification, speech is impossible to hear. May require cochlear implants to recover some of the lost hearing range.

Profound...........................91+ db HL

• Unable to hear even extremely loud sounds (i.e. gunshots, jackhammers, fire alarms) without amplification. Cochlear implants are typically the only viable option.