Types of Hearing Loss

    • Types - describes what part of the ear, or auditory system, is affected
    • Types of hearing loss include
      1. Conductive losses
        • affect the outer and middle ear
        • affect the ability to hear the loudness of sounds (decibels, dB)
      2. Sensorineural losses
        • affect the inner ear
        • affect the ability to hear the loudness of sounds (decibels, dB) and the ability to understand speech clearly
      3. Mixed losses
        • are a conductive and sensorineural hearing loss
      4. Auditory Neuropathy Spectrum Disorder
        • sound goes through the ear normally, but the brain doesn't receive the sound normally
        • issue between the auditory nerve, brainstem, and brain - causes hearing to change (some days/times may be better than others)

    Raising Deaf Kids describes the types of hearing loss.

    The Laurent Clerc National Deaf Education Center also provides information on the types of hearing loss.

    Degrees (Levels of Hearing Loss)audiogramoffamiliarsounds287x303.jpg

    • describes the amount of hearing loss
    • describes the loudness (decibel) level at which sounds can just barely be heard

    Mild hearing loss - 26 to 40 dB

    • Understands conversational speech at a distance of 3-5 feet (face to face)
    • May miss as much as 50% of class discussions if voices are faint or speaker is not in line of vision
    • May have slightly limited speech
    • Difficulty when tired or inattentive, in distant theater seats, in noise of general conversation

    Moderate hearing loss - 41 to 70 dB

    • Conversation must be loud to be understood
    • Will have increased difficulty in group discussions
    • Is likely to have language delays
    • Will probably have limited vocabulary

    Severe hearing loss - 71 to 90 dB

    • May detect loud voices
    • May be able to identify environmental sounds
    • May be able to discriminate vowels
    • Deficient speech and language skills

    Profound hearing loss 91+ dB

    • May detect loud sounds (probably vibrations)
    • Relies on vision rather than hearing
    • Deficient speech and oral language skills

    Configurations of Hearing Loss

    • describes the overall picture of the hearing loss
    • what frequencies (Hz) are affected
      • high frequency hearing loss – only high frequencies are unable to be heard
      • low frequency hearing loss – only low frequencies are unable to be heard
    • how many ears are affected
      • bilateral – hearing loss in both ears
      • unilateral – hearing loss in one ear
    • when or how the hearing loss occurs
      • pre-lingual - hearing loss occurs before language was learned
      • post-lingual - hearing loss occurs after language was learned
      • progressive – hearing loss becomes worse over time
      • sudden – hearing loss happens quickly or quickly and may not last long
    • if the hearing loss changes or remains the same
      • fluctuating – hearing loss that changes, sometimes seeming to improve or to worsen
      • stable – hearing loss does not change

    American Speech-Language-Hearing Association has a patient brochure on Type, Degree, and Configuration of Hearing Loss [Español]. pdf icon

    Simulated Hearing Loss

    Hearing Loss vs. Auditory Neuropathy

    Hearing loss is defined as the decreased ability to take in sound and is the result of a physical affect on a part or parts of the ear (the inner, middle, or outer ear). Auditory Neuropathy, however, is the decreased ability to understand or process sound and is the result of a physical affect on the auditory nerve, also known as the VIIIth cranial nerve. In other words, individuals with Auditory Neuropathy have ears that can physically hear and detect sounds, but have auditory nerves that distort or jumble the sound on the way to the brain, making it difficult for the brain to make sense of or work with the sound. Both, hearing loss and Audtitory Neuropathy can be described as fitting within the broad category of hearing impairment.

    The Auditory Neuropathy Information website was created, by the parent of a child with Auditory Neuropathy, as a resource for other parents that includes:

    • listservs and support groups,
    • simulations of Auditory Neuropathy,
    • books for professionals, educators, and parents,
    • and personal stories about experiences with Auditory Neuropathy

    My Baby's Hearing provides Auditory Neuropathy information on:

    • the causes,
    • how it's diagnosed,
    • and treatment options

    The trends in assessment and treatment of Auditory Neuropathy are shared by The American Speech-Language-Hearing Association.

    Glossary of Terms