Aural rehabilitation in children with cochlear implants: A study of cognition, social communication, and motor skill development

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1 Aural rehabilitation in children with cochlear implants: A study of cognition, social communication, and motor skill development Zahra Jeddi 1, Zahra Jafari 2, Masoud Motasaddi Zarandy 3, Aziz Kassani 4 1 Department of Audiology, University of Social Welfare and Rehabilitation Sciences, Shiraz Cochlear Implant Center, Shiraz University of Medical Sciences, Iran, 2 Department of Basic Sciences in Rehabilitation, School of Rehabilitation Sciences, Rehabilitation Research Center (RRC), Iran University of Medical Sciences (IUMS), Tehran, Iran, 3 Cochlear Implant Research Center, AmirAlam Hospital, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran, 4 Department of Epidemiology, School of Public Health and Nutrition, Shiraz University of Medical Sciences, Shiraz, Iran Objectives: The purpose of this study was to investigate the benefits of aural rehabilitation on the development of cognition, social communication, and motor skills in children with cochlear implants. Methods: The study examined the development of cognition, social communication, and motor skills in 15 deaf children (7 males, 8 females; mean age 45 months 27 days) using the Newsha Developmental Scale before they received the cochlear implants, and then again 2, 4, 6, and 8 months after the implantation. The developmental age, Pretest Developmental Rate, Intervention Efficiency Index, and Proportional Change Index were calculated for each skill. Results: There were significant differences between the preintervention and four follow-up Developmental Rate assessments for cognition, social communication, and motor skills (P < ). Significant differences were also observed between the four follow-up Proportional Change Index assessments for cognition, social communication, and motor skills (P 0.005). Conclusion: Cochlear implantation and aural rehabilitation may result in accelerated rates of cognition, social communication, and motor skill development in deaf children. Keywords: Cochlear implant, Aural rehabilitation, Cognition, Social communication, Motor Introduction Receiving auditory input in early childhood plays a critical role in the development of speech, cognition, and behavior (Quittner et al., 2004). Since the brain is an integrated functional system, early auditory deprivation has negative consequences on higherlevel cognitive processing in addition to hearingrelated impacts (Conway et al., 2011). The difficulties in learning a language and comprehending and expressing speech, as well as the developmental delay in metacognitive processes such as problem solving and attention, decreases these children s ability to create and maintain social communication with their peers (Martin et al., 2011). In addition to the role of the auditory sensory system in the development of cognition and communication, auditory stimulation directs and strengthens visual orientation behaviors. The Correspondence to: Zahra Jafari, Department of Basic Sciences in Rehabilitation, School of Rehabilitation Sciences, Rehabilitation Research Center (RRC), Iran University of Medical Sciences (IUMS), Tehran, Iran. jafari.z@iums.ac.ir, zahra.acn@gmail.com earliest responses of infants to auditory stimuli include the visual-motor behavior of the eyes and head during sound localization. Therefore, the lack of early auditory input in children with severe to profound hearing loss result in motor skill development delays (Gheysen et al., 2008). The access to auditory information provided by cochlear implants appears to positively affect the cognitive, behavioral, and social development of deaf children by facilitating the child s normal neuropsychological development sequence (Quittner et al., 2004; Schlumberger et al., 2004). Despite the impact of hearing loss on the cerebral function, the neuropsychological compensatory mechanisms that result from aural rehabilitation after the implantation enable deaf children to achieve age-appropriate behavioral and cognitive performance levels (Schlumberger et al., 2004). Depending on the role of auditory deprivation, language deprivation (the lack of a verbal representation of motor skills), and emotional factors in the delay in motor skill development, cochlear implantation improves the motor W.S.Maney&SonLtd2014 DOI / Y Cochlear Implants International 2014 VOL. 15 NO. 2 93

2 skills of deaf children through auditory stimulation and its effects on language and social-emotional development (Gheysen et al., 2008). However, there are some reports of no effects of cochlear implantation on balance and motor development (Gheysen et al., 2008; Suarez et al., 2007). Studies suggest that after receiving cochlear implants, deaf children tend to communicate with others more vocally. After many years following cochlear implantation, children adjust to the demands of their social environment, both socially and emotionally (Nicholas and Geers, 2003). Cognitive performance studies demonstrate improvements in cognitive abilities and behavioral development in deaf children after implantation (Edwards et al., 2006). Quittner et al. (2004) suggested that as children with cochlear implants begin to respond to auditory inputs, their attention and ability to adjust their behavior increases, which in turn results in improved parent child relationships. This helps the child master new cognitive and communicative skills. Schlumberger et al. (2004) concluded that the auditory stimulation provided by cochlear implants allows for the development of spatial integration, motor control, and attention for deaf children. On the other hand, a study by Conway et al. (2011) revealed an obvious disturbance of motor sequencing in children with cochlear implants. There is significant variability in the results of cochlear implant use and aural rehabilitation programs in terms of developing cognition, social communication, and motor skills. Periodic and regular evaluations of the developmental rate (DR) of these skills are therefore essential for determining the benefits of aural rehabilitation programs and subsequently counseling the parents as well as designing an efficient rehabilitation program. The purpose of this study was to investigate the benefits of aural rehabilitation on the development of cognition, social communication, and motor skills for a number of Persian-language children with cochlear implants. Methods Participants This study was performed on 15 children with bilateral congenital severe-to-profound sensorineural hearing loss and included 7 boys (46.7%) and 8 girls (53.3%) who received cochlear implants at the AmirAlam Cochlear Implant Center in Tehran (Iran) between August 2010 and January The children s mean age was (±14.45) months. We attempted to select a patient sample that was representative of the studied population. The data on the ages of the children at the time of the hearing loss diagnosis and amplification are shown in Table 1. All children received optimally adjusted bilateral hearing aids and Table 1 Number of children Characteristics of the study participants Age at hearing loss diagnosed (months) Age at hearing aid fitted (months) Age at beginning of rehabilitation (months) Age at cochlear implant operation (months) Group mean Group max Group min were provided with auditory-oral rehabilitation for at least 6 months before the implantations. All of the children received nucleus 24 cochlear implant with ACE strategy in their right ear and had no additional disabilities (e.g. developmental delays, motor deficits, attention deficits, learning disabilities, or mental retardation) other than the hearing loss. Their hearing loss was not syndromic or caused by a genetic deficit. The incidence of auditory neuropathy spectrum disorder was ruled out in these children based on the cochlear implant center database related to the medical history of deaf children (including risk factors for Auditory Neuropathy Spectrum Disorder [ANSD]), audiological history (including the results of ABR and OAE tests), and normal magnetic resonance imaging results. The etiology of hearing loss was unknown. The children s parents were monolingual Persians with normal hearing who used oral communication. The parents of all children were of low educational level and moderate economic circumstances. The study subjects were selected based on information related to the audiological and medical assessments in the AmirAlam Cochlear Implant Center database and by the parents completion of a medical history form, which included demographic information as well as birth, medical, and hearing loss histories. This study was approved by the ethics committee of the Tehran University of Medical Sciences. Procedure In this longitudinal study, we used the Newsha Developmental Scale to assess the children s cognition, 94 Cochlear Implants International 2014 VOL. 15 NO. 2

3 social communication, and motor skills. The children s parents were asked to answer questions related to each of the above-mentioned skills using the scale. An assessment was performed one week before the children received the cochlear implants and then again after the implantation at regular intervals of 2 months for 8 months. In the motor skill assessment, some children achieved age-appropriate skills in the age range of months on the Newsha Developmental Scale before the completion of the follow-up assessments. Therefore, these children were excluded in the next time interval. Accordingly, 14 children were assessed at the first follow-up assessment, 12 at the second, 7 at the third, and 6 at the fourth. The aural rehabilitation program used auditoryverbal communication to train the hearing-impaired children with cochlear implants. The children underwent auditory training by an audiologist skilled in cochlear implant rehabilitation for two 1-hour sessions per week. They were also trained in language and speech skills by an expert speech therapist for two 1-hour sessions per week. In each session, while performing the intervention with the child, the therapist trained the parents to do the practices at home. Given the ethical considerations and the cochlear implant center regulations, we did not implement a control group with an alternative rehabilitation program or no program. Newsha developmental scale This is a Persian criterion-referenced assessment designed for children 0 6 years of age. The scale assesses the main developmental areas of auditory, speech, receptive and expressive language, cognition, social communication, and motor skills in 13 age ranges: level 1 (0 3 months); level 2 (4 6 months); level 3 (7 9 months); level 4 (10 12 months); level 5 (13 15 months); level 6 (16 18 months); level 7 (19 24 months); level 8 (25 30 months); level 9 (31 36 months); level 10 (37 42 months); level 11 (43 48 months); level 12 (49 60 months); and level 13 (61 72 months). This scale is intended to determine whether the development trajectory of each of the developmental areas is normal or delayed. The child s progress curve during the rehabilitation program can be depicted by using this scale. Interpretation of the results is based on the minimum and maximum scores, with each item scoring one point. If a child achieves the minimum score or above, then the child is said to have ageappropriate developmental skills. However, if the child scores less than the minimum over two assessments separated by less than one week, their developmental delay can be calculated by completing the scale for lower age ranges. The reliability of this scale is 95%, and its content validity index for various skills across age groups is between 0.8 and 1 (Jafari and Malayeri, 2012). For example, there were five items regarding social communication skills for the age range of months, including (1) the child s selfconfidence is high; (2) when the child speaks with others, his speech has an appropriate tone; (3) the child initiates the conversation; (4) the child follows changes in the topic of conversation; and (5) the child uses speech for information exchange and to express needs and feelings. A passing score of this scale is 3 5. Calculation For each time interval, the child s score in each of the studied skills was determined based on the parent s response to the items on the Newsha Developmental Scale. For each skill, the developmental age was determined by the upper limit of the age range in which the child achieved the required score. The DR was then calculated by dividing the developmental age by the chronological age. This index shows the rate of development (McNamara et al., 1994). For the time intervals following cochlear implantation, the Intervention Efficiency Index (IEI) and the Proportional Change Index (PCI) were calculated to evaluate the benefits of the aural rehabilitation program on the rate of development. The IEI was calculated by dividing the difference between the pre- and post-test developmental ages by the time interval between the pre- and post-tests. This index revealed the rate of development during the intervention. The IEI was then divided by the Pretest Developmental Rate (PDR), resulting in the PCI, which is indicative of the efficiency index of the aural rehabilitation program (PCI = IEI/PDR) (McNamara et al., 1994). The following is an example of the calculations applied in this study: If a child is 26 months old and his cognitive skill is at level 6 (16 18 months) on the Newsha Developmental Scale, the DR will be 18/ 26 = If after 2 months of rehabilitation treatment, the cognitive skill level of this child reaches level 7 (19 24), the difference between the pre- and post-test developmental ages is = 6 months, and consequently, IEI will be 6/2 = 3. Finally, PCI is calculated by dividing the IEI value by the DR value for previous stage (PDR): PCI = 3/0.692 = Data analysis Due to the small sample size (n = 15), we used the nonparametric Friedman test for comparison between the preintervention assessment and the 4 follow-up assessments of DR and also for the comparison of the four IEI and PCI follow-up assessments in all the studied skills. Data analysis was performed using SPSS 18.0, and P < 0.05 was considered significant. Cochlear Implants International 2014 VOL. 15 NO. 2 95

4 Results Developmental age The mean chronological and developmental ages in terms of cognition and social communication skills are shown in Fig. 1. As can be seen in this figure, the mean developmental age of the children increased with every 2 months following cochlear implantation and aural rehabilitation, and gradually approached their mean chronological age at the end of the aural rehabilitation program. Fig. 2 reveals the mean chronological and developmental ages of the children in terms of motor skills. After 2 months of using the device and rehabilitation, the mean developmental age of the children coincided with their mean chronological age. In the subsequent time intervals, the developmental age exceeded the chronological age. Since some children achieved ageappropriate skills in the age range of months on the Newsha Developmental Scale before completion of the follow-up assessments, thus the sudden drop in chronological age at time interval 3 resulted from the decrease in the number of studied children and the younger children remaining. Moreover, the time frame of 12 months for levels 12 and 13 in Newsha Developmental Scale resulted in a sudden increase in the developmental age, thereby widening the gap between chronological and developmental ages. Developmental rate Fig. 3 illustrates the mean and standard deviation of the DR at the preintervention and four follow-up stages. A significant increase was observed in the DR for cognition and communication skills following aural rehabilitation (P < ). There was also a significant increase in the DR for motor skills following aural rehabilitation (P < ). Intervention efficiency index The mean and standard deviation of the IEI for the four follow-up assessments are shown in Fig. 4. There were significant differences between the four follow-up IEI assessments for cognition and social communication skills (χ 2 (3, N = 15) = 27, P < and χ 2 (3, N = 15) = , P = 0.006, respectively). However, there was no significant difference between the first, second, and third follow-up assessments for motor skills (χ 2 (2, N = 7) = 2, P = 0.368). Figure 1 The chronological and developmental ages in terms of cognition and social communication at preintervention and four follow-up assessment stages. Figure 2 stages. The chronological and developmental ages in terms of motor skills at preintervention and four follow-up assessment 96 Cochlear Implants International 2014 VOL. 15 NO. 2

5 Figure 3 The mean DR at preintervention and four follow-up assessment stages in term of cognition, social communication, and motor skills. Figure 4 The mean IEI at 2, 4, 6, and 8 months after implantation. Proportional change index The results of PCI calculations at all assessment intervals are presented in Fig. 5. Significant differences were observed between the four follow-up assessments of the PCI in cognition, social communication, and motor skills (χ 2 (3, N = 15) = , P < ; (χ 2 (3, N = 15) = , P = 0.005; and (χ 2 (3, N = 6) = 18, P < , respectively). Discussion Deaf children showed remarkable delay in cognitive skills development. After the implantation and during the 8 months of aural rehabilitation process, cognitive skills developed at a higher rate than those of normal hearing children, and thus, the cognitive level in these children became close to that of normal hearing children. Similarly, Harris et al. Figure 5 The mean PCI at 2, 4, 6, and 8 months after implantation. Cochlear Implants International 2014 VOL. 15 NO. 2 97

6 (2011), in a study on the memory development of deaf children who have used cochlear implants for 2 years, demonstrated that rehabilitation increased the DR of verbal memory in these children, which in turn increased the development of spoken language. Khan et al. (2005), in a study on the cognition and behavior of children with cochlear implants, concluded that after cochlear implantation deaf children can behave at a cognition level identical to that of normal hearing children. Quittner et al. (2004) reported the prominent effect of cochlear implantation on the improvement in social, behavioral, and cognitive development of deaf children. Although in this study both verbal and nonverbal cognitive skills showed clear improvement after implantation, a number of studies revealed improvement in nonverbal cognitive skills only. For example, in a study by Shin et al. (2007), on the cognitive skills of 17 children with cochlear implants after using the device for 6 months, the nonverbal cognitive functions of these children approached the normal range. However, their performance with regard to information, comprehension and similarity, and mathematics skills requiring verbal abilities showed no change. Edwards et al. (2006) also demonstrated the nonverbal cognitive function improvement and the behavioral and emotional development of deaf children during the first year following implantation. This dichotomy between the findings of our study and those above can be attributed to the difference in tests used to assess cognitive skills; for example, the study of Shin et al. used a neuropsychological test, but a developmental scale was used in the present study. The delay in cognitive skill development in deaf children is the result of interaction between auditory sensory and cognitive processing. Auditory signals include complex information such as temporal aspects which activate the neural pathways underlying cognitive processing. Moreover, limited exposure to spoken language as a result of hearing loss restricts the likelihood of representation of linguistic codes necessary for cognitive processing. The decrease in the development of cognitive processing caused by auditory deprivation leads to decreased cognitive abilities in deaf children. The cochlear implants help develop cognitive skills by providing auditory stimulation along with aural rehabilitation to facilitate the development of processing procedures by training activities that require vocal and cognitive processing. These procedures are essential for performing the cognitive tasks. Subsequently, the children with cochlear implants develop ageappropriate cognitive functions after many years of using the device and undergoing rehabilitation. In this study, the mean DR of social communication at the preintervention stage was Values less than 1 suggest a delay in the acquisition of this skill. After implantation and rehabilitation, the DR increased and approached 1. However, at the end of 8 months of rehabilitation, these children did not demonstrate the age-appropriate communication skills. This finding is consistent with the results of other studies. For example, Le-Maner Idrissi et al. (2008) in a study on the communication skills of 20 children with cochlear implants concluded that the communicative abilities of the children increased 1 year after implantation, resulting in their developmental age coinciding with their chronological age. A study by Stacey et al. (2006) demonstrated the increasing social independence of deaf children after using a cochlear implant for 4 years. Bat-Chava et al. (2005), in a longitudinal study on communication skills of children with cochlear implants, demonstrated a noticeable progress in communication skills during the use of the device and demonstrated that these children achieve age-appropriate skills after several years implant use. The delay in the development of spoken language and speech caused by the lack of early auditory input in deaf children decreases their ability to communicate with others, thereby leading to a gap between the developmental and chronological ages. Cochlear implants present the auditory input needed for language and speech development. In addition, intervention practices enable the child to use the spoken language for social communication with others. The presence of the gap between the developmental and chronological ages after 8 months of aural rehabilitation in this study calls for a longerterm aural rehabilitation program for children with cochlear implants until they achieve age-appropriate social skills. Our study children s social communication skills developed at a higher rate than those of normal hearing children, which is corroborated by IEI values greater than 1. A study by Tait et al. (2007) on preverbal communication skills of children with normal hearing and children with cochlear implants demonstrated that the auditory and verbal communication of children with cochlear implants developed in the same pattern and at the same rate as that observed in normal hearing children. PCI greater than 1 reveals the positive influence of the aural rehabilitation on the development of communication. Harrigan et al. (2002) assessed the effects of interaction training on the communication skills of children with cochlear implants and their parents and concluded that 12 months after the training, the children s spoken responses to their parents were almost double those during the pretraining. In this study, there was a delay in motor skill development in the deaf children before implantation, which resulted in a gap between the developmental and chronological ages. Schlumberger et al. (2004) in a study on the non-verbal development of deaf 98 Cochlear Implants International 2014 VOL. 15 NO. 2

7 children revealed that there is the clear delay in complex movements of deaf children compared with that in children with normal hearing, but there is no difference between these two groups with regard to simple movements. Similarly, in this study children had been evaluated by the age of months and thus complex motor skills were included. Horn et al. (2006) also believed that there is no initial delay in the motor skills of deaf children, but that this becomes evident with time. These authors demonstrated that auditory deprivation leads to the delayed development of certain motor and language skills in deaf children. A study by Gheysen et al. (2008) also mentioned the delay in motor skill development of deaf children. In this study, during the first 2 months of cochlear implant use, motor skills developed at a higher rate than in normal hearing children, so that the motor skills level of deaf children reached to their hearing peers level of performance. Therefore, implantation and rehabilitation was effective in acceleration of motor development in deaf children. Contradictory findings have been reported on this subject. Schlumberger et al. (2004) suggested that cochlear implants resulted in an improvement in motor skills; however, the children with cochlear implants in the study by Schlumberger et al did not achieve age-appropriate motor skills. Cushing et al. (2008) demonstrated that deaf children achieved marginal gain from cochlear implantation in terms of balance function, but they showed poor performance compared with children with normal hearing. The controversy between this study and the studies of Schlumberger et al. and Cushing et al. may have been due to differences in size of the cohorts and characteristics of the cohorts. Nevertheless, Cushing et al. suggested that some children achieve balance performance following cochlear implantation at or above their age level. On the other hand, a study by Suarez et al. (2006) showed that cochlear implantation has no effect on sensory organization. In a study by Gheysen et al. (2008) who used a performance test and an observational checklist for assessment of motor development, it was suggested that children do not show better motor performance following cochlear implantation than children not so treated. Unlike the study of Suarez et al, which focused on postural control, in this study children s overall motor development was assessed using a developmental scale. Moreover, our assessments were done based on the reports of parents who judged their children s performance based on daily activities. Given that children rely on other sensory systems for control of movement, such as visual and somatosensory inputs, it is not clear whether the improvement in motor skills noted in this study relates solely to the restoration of auditory input. Clarification would require the control of confounding factors to determine the exact cause of such improvement. In our study, we employed numerical indices to determine the DRs of children with cochlear implants participating in an aural rehabilitation program, which enabled the clinician to assess the children s development quantitatively. The final computed index (PCI) not only indicated increased scores, but also compared each child s rate of development at pretesting to his or her rate of development during intervention. However, the indices had two disadvantages: (i) they required that performance be measured or transformed into developmental age equivalents and (ii) assume that development is progressing in a linear fashion (Ottenbacher et al., 1988). This study was performed on 15 deaf children who received cochlear implants at the AmirAlam Cochlear Implant Center. The limitations of this study include the small sample size and short period of follow-up. Given that the families of hearingimpaired children are referred to the cochlear implant center from various regions of Iran, and due to poor cooperation from the other families, it is difficult to follow up larger groups of children for a longer period of time. Continued research with larger numbers of children over longer intervals of intervention is required for a more complete evaluation of the benefits of aural rehabilitation in order to counsel the parents of children who underwent cochlear implantation. In addition, subjective observation of progress with regard to the developmental skills of children based on their parents completion of the Newsha Developmental scale results in a bias on the part of the parents caused by their expectation levels following implantation. However, we used a homogenous sample of parents in terms of educational level and attempted to ensure that the parents understood each item of the scale correctly through sufficient and detailed illustration of those items. Conclusion Using the Newsha Developmental Scale, this study examined the benefits of an aural rehabilitation program on the development of cognition, social communication, and motor skills in children with cochlear implants. Following the 8 months of cochlear implant use and aural rehabilitation, developmental skills level of deaf children became close to their hearing peers level of performance and this can be attributed to a higher rate of development than that of normal hearing children during this period. The results of this study demonstrate that these children had benefited from cochlear implant and aural rehabilitation in terms of cognition, social communication, and motor skills successfully. Clinicians can check the children s progression curve through regular and periodic Cochlear Implants International 2014 VOL. 15 NO. 2 99

8 assessments. They can also use these results to counsel the parents of children with cochlear implants on the importance of aural rehabilitation in developing their child s cognition and communication and the benefits of rehabilitation on motor skill development of these children. In addition, the results of this study will help clinicians design efficient rehabilitation programs for children with cochlear implants. Acknowledgements The outstanding cooperation of all parents of hearingimpaired children and also the personnel of the AmirAlam Cochlear Implant Research Center for their administrative support, especially Mr Farzad Mobedshahi in this study is greatly appreciated. References Bat-Chava Y., Martin D., Kosciw J.G Longitudinal improvements in communication and socialization of deaf children with cochlear implants and hearing aids: evidence from parental reports. Journal of Child Psychology and Psychiatry, 46(12): Conway C.M., Karpicke J., et al Nonverbal cognition in deaf children following cochlear implantation: Motor sequencing disturbances mediate language delays. Developmental Neuropsychology, 36(2): Cushing S.L., Papsin B.C., Rutka J.A., James A.L., Gordon K.A Evidence of vestibular and balance dysfunction in children with profound sensorineural hearing loss using cochlear implants. The Laryngoscope, 118(10): Edwards L., Khan S., Broxholme C., Langdon D Exploration of the cognitive and behavioural consequences of paediatric cochlear implantation. Cochlear Implants International, 7(2): Gheysen F., Loots G., Van Waelvelde H Motor development of deaf children with and without cochlear implants. Journal of Deaf Studies and Deaf Education, 13(2): 215. Harrigan S., Nikolopoulos T.P Parent interaction course in order to enhance communication skills between parents and children following pediatric cochlear implantation. International Journal of Pediatric Otorhinolaryngology, 66(2): Harris M.S., Pisoni D.B., Kronenberger W.G., Gao S., Caffrey H.M., Miyamoto R.T Developmental trajectories of forward and backward digit spans in deaf children with cochlear implants. Cochlear Implants International, 12: Horn D.L., Pisoni D.B., Miyamoto R.T Divergence of fine and gross motor skills in prelingually deaf children: implications for cochlear implantation. The Laryngoscope, 116(8): Jafari Z., Malayeri S The psychometric properties of Newsha Developmental Scale: an integrated test for Persian speaking children. Iranian Journal of Pediatric, 22(1): Khan S., Edwards L., Longdon D The cognition and behaviour of children with cochlear implants, children with hearing aids and their hearing peers: a comparison. Audiology and Neurotology, 10(2): Le Maner-Idrissi G., Barbu S., Bescond G., Godey B Some aspects of cognitive and social development in children with cochlear implant. Developmental Medicin & Child Neurology, 50(10): Martin D., Bat-Chava Y., Lalwani A., Waltzman S.B Peer relationships of deaf children with cochlear implants: predictors of peer entry and peer interaction success. Journal of Deaf Studies and Deaf Education, 16(1): 108. McNamara R., Johnson D., et al The SKI*HI Manual. Logan, 1:19 21 Nicholas J.G., Geers A.E Personal, social, and family adjustment in school-aged children with a cochlear implant. Ear and Hearing, 24(1): 69. Ottenbacher K.J., Johnson M.B., Hojem M The significance of clinical change and clinical change of significance: issues and methods. The American Journal of Occupational Therapy, 42(3): Quittner A.L., Leibach P., Marciel K The impact of cochlear implants on young deaf children: new methods to assess cognitive and behavioral development. Archives of Otolaryngology Head and Neck Surgery, 130(5): 547. Schlumberger E., Narbona J., Manrique M Non-verbal development of children with deafness with and without cochlear implants. Developmental Medicine Child & Neurology, 46(9): Shin M.S., Kim S.K., Kim S.S., Park M.H., Kim C.S., Oh S.H Comparison of cognitive function in deaf children between before and after cochlear implant. Ear and Hearing, 28(2): 22. Stacey P.C., Fortnum H.M., Barton G.R., Summerfield A.Q Hearing-impaired children in the United Kingdom, I: Auditory performance, communication skills, educational achievements, quality of life, and cochlear implantation. Ear and Hearing, 27(2): 161. Suarez H., Angeli S., Suarez A., Rosales B., Carrera X., Alonso R Balance sensory organization in children with profound hearing loss and cochlear implants. International Journal of Pediatric Otorhinolaryngology, 71(4): Tait M., De Raeve L., Nikolopoulos T.P Deaf children with cochlear implants before the age of 1 year: Comparison of preverbal communication with normally hearing children. International Journal of Pediatric Otorhinolaryngology, 71(10): Cochlear Implants International 2014 VOL. 15 NO. 2