Hearing Loss and Deafness - Levels Of Hearing Loss

Hearing loss is measured in decibels (dB) and is generally subdivided into three major groups. A loss greater than 55 dB is considered severe to moderate. Hearing loss is termed severe if it averages between 70 and 90 dB. Averaged across all frequencies, a hearing loss in the better ear of 90 dB or greater is considered profound. A child with mild loss of less than 40 dB may still be able to hear speech and have only moderate difficulties. With a loss between 40 and 55 dB some children can still hear some speech sounds, and these children may get a boost from a hearing aid.

In addition to the degree of hearing loss, the frequency range that is affected profoundly influences hearing ability. A child with mild hearing loss across the frequencies used for producing speech may have more difficulties. Speech will sound quite distorted and less intelligible for a child with 55 dB loss, who will hear more vowels than consonants, since vowels are transmitted at higher frequencies. A complete audiometric assessment of a child's hearing loss must, therefore, provide information for each ear, across a range of frequencies.

Additional problems suffered by hearing impaired children are: brain damaged (8%), cerebral palsy (7%), heart disorder (6%), perceptual-motor difficulties (10%), emotional and behavioral problems (19%), and visual deficits (18%)" (Harris 1990, p.208).