Spoken Language gets a Piggy-back Ride on Language in any Modality
A chapter on Early Identification, Communication Modality, and Development of Speech and Spoken Language Skills: Patterns and Considerations by Dr. Christine Yoshinaga-Itano, Ph.D. from the University of Colorado at Boulder from a soon to be released book by Oxford Press, reveals insightful information about how young children develop speech and spoken language. The following are excerpts from this important work.
Despite the volume of research on speech development of children with significant hearing loss, there are many unanswered questions about how speech and spoken language develop, what methods of intervention are the most effective, and what variables predict optimal spoken language outcomes. One variable of special interest has been that of age of identification of hearing loss: Will children whose hearing loss is identified during the neonatal period achieve better speech and spoken language skills than those who are identified at later ages? The increasing adoption of universal newborn hearing screening, that is, hearing testing of all infants at or near birth, is providing a first opportunity to be able to investigate these issues in a large population of children.
Expressive language ability in any modality plays a major role in the development of spoken language development. The first part of this chapter presented information about speech and spoken language development of both early and later-identified children between the ages of birth and six years of age. Expressive language development (even if expressed through signs) and degree of hearing loss play a major role in predicting spoken language outcome for children with hearing loss. In the first three years of life, all children with hearing loss, even those with mild early-identified losses, are more like other children with hearing loss than they are like hearing children. When considering speech development, two categories of hearing loss are pertinent, those with mild through severe hearing loss and those with profound hearing loss. Profound hearing loss with conventional amplification results in greatly decreased potential for spoken language development in the first five years of life, even with early identification and intervention. However, early-identified profound hearing loss with early cochlear implantation and a highly quality auditory stimulation program results in expectations that are similar to early-identified mild-to-severe hearing loss and the use of conventional amplification.
Three of the profoundly deaf children described in case studies in the study had substantial sign vocabulary before implantation, that is, at or above the average vocabulary range for hearing children on the MacArthur (about 50th percentile). None of the three appeared to have any spoken language at implantation, according to their MacArthur reports. All three wore amplification, but had no documented speech perception or speech discrimination skills prior to cochlear implantation. However, they had some awareness of sound and some ability to produce vocalizations before implantation. All three received a high quality auditory and speech stimulation program provided in a parent-centered home intervention program prior to implantation. It should be noted that this combination of different modalities is an unusual characteristic of the CHIP program (The Colorado Home Intervention Program where all three children received services). In addition to establishing universal newborn hearing screening programs, intervention follow-through programs also changed. Intervention providers agreed to allow parents to make choices and to request options that were not typically within the mode of communication options. As a result some parents began to ask for American Sign Language instruction and to combine this with an auditory and speech stimulation program. Thus, there is an unusual combination from early infancy of American Sign Language and auditory/speech stimulation in the case of one of the children, Hillary.
After cochlear implantation, all three children appeared to fast map their speech production onto their sign vocabulary; chronological-age-appropriate or near-age-appropriate spoken vocabulary was acquired within 12-14 months post-implant. Hillary's development was slightly slower than that of the other two children, probably due to the impact of the severe visual progressive disorder. However, there are strong similarities in the rapid increase from non-verbal to intelligible speech. This development appears to be evidence of an oral phonology piggy-back onto the lexical sign language foundation. That is, these three children discovered that the sounds they were hearing with the cochlear implant were just another code for the sign vocabulary that they used to communicate. Following this discovery, a rapid mapping of the sounds of English onto the sign vocabulary appears to have happened.
These case histories represent an unusual first language to second language transition, which is transition from language in a visual/manual modality to language in an oral/auditory modality. The "first language" in the first two cases was incomplete with respect to syntax and morphology, pragmatics and phonology. In the first two cases, there was a simultaneous mapping of sign language to oral speech, while in Case 3, the family used American Sign Language with no speech and began to transition to a pidgin Signed English (combined with speech) after the cochlear implantation.
One of the unique aspects of the use of spoken English with manually-coded English is that the child receives two language symbols simultaneously. This simultaneous presentation may account for the unusually rapid development of the spoken English system. In other bilingual models, presentation of the vocabulary in the two languages is at best sequential, so that the cognitive demands must be much greater. Yoshinaga-Itano and Menn (2003) suggested that this simultaneous presentation is the reason that these children were able to transition from no spoken words to over 500 English words in the space of about 6-8 months, even faster than what is found in typical first language development. The first 6 months involved the development of listening and the acquisition of vowel/diphthong and consonant phones and the second 6-8 months post cochlear implant stimulation involved a rapid mapping of these newly learned sounds onto hundreds of signed words.
By Janet DesGeorges © Hands & Voices 2004, Excerpted from Christine Yoshinaga-Itano, Ph.D