Speech norms were developed through the collection of half-hour videotaped interactions of parent-child recorded every 6 months from about 9 months to 36 months of age for most of the children. A select sample of 150 children were followed through age 7 years. These children differ from the larger cohort because they represent only children who have no other additional disabilities.

Number of different phonemes and Speech Intelligibility:

Speech norms are available for the development of the number of different vowels and consonants at each age level for each degree of hearing loss and includes a category for children with cochlear implants. Data is also available for early- and late-identified children and for children with and without additional disabilities.

Ultimately, the child is learning individual speech sounds and combinations of speech sounds to develop intelligible speech. The following slides provide information about the development of speech intelligibility by age, expressive language quotient, degree of hearing loss, and cognitive level,

Speech Intelligibility

Speech-intelligibility

Speech Development of infants and young children who are deaf or hard of hearing can also be described for each individual phoneme.

Development of Individual Vowels in non-words by degree of hearing loss

Dev-Individual-Vowels-non-words-by-degreeHL

Children with Mild and Moderate Hearing Loss

Children with Moderate-Severe and Severe Hearing Loss

Children with Profound Hearing Loss and conventional amplification

Children with Profound Hearing Loss and Cochlear Implants – Development of Individual Vowels in true words by degree of hearing loss
Dev-vowels-in-true-words-by-HL-and-age

Children with Mild and Moderate Hearing Loss

Children with Moderate-Severe and Severe Hearing Loss

Children with Profound Hearing Loss and conventional amplification

Children with Profound Hearing Loss and Cochlear Implants