How is Hearing Loss Described
- Type of Hearing Loss
- Degree of Hearing Loss
- Progressive / Sudden Hearing Loss
- Fluctuating / Stable Hearing Loss
- Syndromic / Nonsyndromic Hearing Loss
Degrees of hearing lossAll types of hearing loss (conductive, sensorineural, or mixed) can vary from mild (only a little hearing loss) to profound (little or no usable hearing).
Most children have some degree of measurable hearing. Only a very small percentage of children with hearing loss experience complete deafness.
The degree of hearing loss refers to how much hearing loss is present. There are five broad categories used to describe the degree of hearing loss. The numbers listed below represent the lowest frequency (or softest) sounds a person can hear.
- Normal hearing to slight hearing loss (0 – 25 decibels, or dB)
People with slight hearing loss (20 – 25 dB) may have trouble hearing faint (quiet) speech. They may also have to listen carefully in important or difficult situations.
- Mild hearing loss (26 – 40 dB)
For people with mild hearing loss, understanding speech can be difficult. They can usually hear well if they are listening to a single person speak in a quiet situation. However, they have trouble hearing faint or distant speaking. People with mild hearing loss usually can benefit from hearing aids or FM systems.
- Moderate hearing loss (41 – 55 dB)
Listening is a strain for people with moderate hearing loss. While they can understand what a person says if the person is close, it can be difficult for them to hear someone else in a noisy environment. People with moderate hearing loss may miss 50 – 75% of speech in a conversation, and often need to have part of the conversation repeated. People with moderate hearing loss usually can benefit from hearing aids or FM systems.
- Moderate – severe hearing loss (56 – 70 dB)
People with moderate – severe hearing loss can miss up to 100% of speech in a conversation, and need for a conversation to be very loud. Again, people with moderate – severe hearing loss usually can benefit from hearing aids or FM systems.
- Severe hearing loss (71 – 90 dB)
People with severe hearing loss may hear a loud voice, if the person speaking is one foot (12 inches) away from his/her ear. They may be able to identify noises in their environment (for example, a paper rustling or traffic outside), but often appear to be ignoring conversation from the people around them.
- Profound hearing loss (over 90 dB)
People with profound hearing loss are considered to be deaf. They may detect very loud sounds, and are usually aware of vibrations (movements) around them. People with this degree of hearing loss may rely on vision (sight), rather than hearing, as their main way of communicating with other people. People with profound hearing loss may benefit from treatments or therapies that amplify sound (make sounds louder), but may benefit more from a cochlear implant.
For more information about the treatments and therapies mentioned on this page, please click here.
LateralityThis describes whether the hearing loss is unilateral (hearing loss in one ear only) or bilateral (hearing loss in both ears).
SymmetryChildren with symmetrical hearing loss have the same degree and configuration of hearing loss in both ears. Children with asymmetrical hearing loss have a different degree and/or configuration of hearing loss in each ear.
Progressive or sudden hearing lossProgressive hearing loss is hearing loss that becomes worse over time. Sudden hearing loss is hearing loss that occurs quickly (within less than 90 days, or 3 months) and requires immediate medical attention to identify its cause and treatment.
Fluctuating or stable hearing lossFluctuating hearing loss is hearing loss that changes, sometimes getting better and sometimes getting worse. This type of hearing loss is usually associated with conductive hearing loss (caused by an ear infection, for example), but may be present in other conditions. Stable hearing loss is hearing loss that does not change over time.
Syndromic or Nonsyndromic Hearing LossThere are many different causes of hearing loss. Hearing loss in infants and children is most commonly caused by fluid in the middle ear or ear infections. These are usually treatable.
People may have syndromic hearing loss (hearing loss associated with other symptoms or features of a condition) or nonsyndromic hearing loss (usually caused by a change within one of the genes related to hearing).
- For more information on conditions or syndromes associated with hearing loss, please click here.
- For more information on genetic causes of hearing loss, please click here.
Hearing loss can also happen due to exposures to certain viruses, diseases, or drugs; long-term exposure to noise; complications related to birth; tumors; or aging.