[An assessment tool for analysing the early vocal development of young children with cochlear implant]

Early vocal development of German-speaking cochlear implant recipients has rarely been assessed so far. There-fore the purpose of this study was to describe the early vocal development following successful implantation.

A case study was designed to assess the temporal progression of early vocal development in a young cochlear implant recipient who was bilaterally implanted at the age of 8;3 months. Data were collected during one year by recording parent-child interactions on a monthly basis. The first recording was made before the onset of the signal-processors, the 12 following recordings were made during the first year of implant use. The child's vocalizations were classified according to the vocalization categories and developmental levels from the Stark Assessment of Early Vocal Development--Revised (SAEVD-R). This assessment tool was translated into German in this study and used with German-speaking children for the first time. It allows a coding of prelinguistic utterances via auditory perceptual analysis.

The results show an overall decrease of early vocalizations and an increase of speech-like vowels and consonants. In the first six months no apparent progress took place; The child produced almost exclusively vocalizations from Levels 1-3. In the second half of the year an increase of canonical utterances (Level 4) and advanced forms (Level 5) was observed. However, vocalizations beyond the canonical babbling phase, especially vocants and closants as well as their combinations, continued to be dominant throughout the first year of implant use. The progress of development of the child investigated in this study is comparable to other children implanted at young age who had also been assessed with the SAEVD-R. In comparison to normal-hearing children, the implanted child's development seemed to progress slightly faster. Interrater- and intrarater-reliability using the SAEVD-R were measured for two independent observers and for a first and second coding procedure and revealed to be acceptable to good.

The use of SAEVD-R for an implanted German-speaking child allowed the investigation of prelinguistic vocal development before the onset of words. The fact that early vocalizations remain the dominant form throughout the first year of hearing experience emphasizes the importance of documenting and analysing prelinguistic vocal development in order to monitor progression of speech acquisition.