Population of the study
The sample of this study included 46 Egyptian children who suffered from congenital bilateral severe to profound sensori-neural hearing loss since birth and underwent CI procedure, the mean age of children at the time of implantation was 3 ± 0.5 years, minimum age of implantation was 2 years and maximum age of implantation was 4.3 years. Children’s chronological ages at the time of data collection ranged from 4.5 to 5 years (mean of 4.7 ± 0.1 years) and all have the same socio-economic strata. Inclusion criteria were; children with prelingual unilateral cochlear implant and with average intellectual abilities, All children were regular in the same auditory and language intervention program applied at phoniatrics unit in Kasr Alaini hospital, Cairo University by expert phoniatricians, with the same frequency of sessions for at least 6 months duration (mean duration of therapy 23.42 ± 13.84 months) with no past history of language rehabilitation. Exclusion criteria were; children with neurological disorder, psychological disorders or with other disabilities and Children who have interrupted course of rehabilitation. Comparison regarding the development of language abilities was done between children who were implanted before the age of 3 years (22 child) and after the age of 3 years (24 child) and between children who received rehabilitation for less than 1 year (18 child) and group of children who received rehabilitation for 2 years or more (28 child). The results of language assessment of the CI children were compared to normative data of typically developed children of an equivalent age.
Methodology
Detailed history taking included: the current chronological age, the age of cochlear implantation, family history of similar conditions, perinatal history, developmental history, history of childhood illness, history of hearing aids use, previous language therapy and current mean of communication. All children were subjected to a thorough clinical examination. There were no associated disorders and all children were of normal examinations.
A Proficient Preschooler Language Evaluation (APPLE TOOL) [
12] was applied for cochlear implanted children in this study to assess the development of different language domains. This tool was designed to evaluate different receptive and expressive language skills for native Arabic speaking children. Not only dose APPLE tool reveal receptive and expressive scores, but it also allows accessing scores for various components of language. It is a battery of several tests that includes:
Receptive vocabulary (RV): Miscellaneous picture covering different semantic group were introduced. The items included in this subtest also vary as regards level of difficulty and degree of familiarity (Total number of items of this subtest is 55).
Linguistic concepts (LC): Evaluate the child's ability to connect words with meaning and use words to refer to concepts (Total number of items of this subtest is 48).
Sentence comprehension (SC): Evaluate the child's ability to understand orally presented sentence pairing various grammatical structures (Total number of items of this subtest is 35).
Understanding oral instructions (UOI): Evaluate the child ability to follow or orally- presented instructions, a set of sheets involving pictures of many objects are introduced.For each sheet instruction is given by assessor. The instructions included in this subtest involved, for example: Sequential instructions involving different number of items or temporal indicators (Total number of items of this subtest is 28).
Expressive vocabulary (EV): various pictures sequentially introduced and the child is asked to label each of them (Total number of items of this subtest is 84).
Expressive vocabulary_1 (EV_1): This subtest evaluates the child's ability to verbally describe functions of object (Total number of items of this subtest is 16).
Morphosyntax (MS): Evaluate the child's knowledge of grammatical rules in a sentence completion task, child is asked to complete an orally presented sentence that is related to the introduced picture stimulus (Total number of items of this subtest is 60).
Word, Phrase and Sentence Repetition (REP): Evaluate the child's ability to recall and reproduce words, phrases and sentences of varying lengths and syntactic complexity, he or she is asked to repeat sentence that are orally presented by the examiner. Verbal stimuli included in this subtest are graded in difficulty and regards both length and structure complexity (Total number of items of this subtest is 22).
In All subtests, repetitions are allowed (but only before the child produce wrong responses) except in word, phrase & sentence repetition task. Each question is graded from 0 to 1 in all subtests except for Word, Phrase and Sentence Repetition (REP) each question is graded from 0 to 4; with score 4 for repetition with no errors, 3 for repetition with one error, 2 is for repetition with two errors, 1 for repetition with three errors and 0 score for repetition with four error or more.
A pilot study was carried out on 10 children prior to the study to ensure the APPEL tool applicability to the cochlear implanted children.