Efficacy Of Cochlear Implantation Research Articles

Cochlear Implantation in Children Younger Than 12 Months

As a result of universal newborn hearing screening and improved evaluation tools, many children with severe to profound hearing loss are being diagnosed as infants. This affords the opportunity to provide these children access to cochlear implantation, although medical and audiologic challenges must be addressed. The purpose of this study was to investigate the safety and efficacy of cochlear implantation in children who are younger than 1 year. A prospective study was conducted of 18 children who had confirmed severe to profound sensorineural hearing loss and received cochlear implants at our medical center before 12 months of age. The length of device usage ranged from 6 months to 4 years, 5 months. The main outcomes measured were perioperative and postoperative surgical/medical aspects, the Infant-Toddler Meaningful Auditory Integration Scale and age-appropriate phoneme, and word and sentence recognition tests, when appropriate. All children had full insertions of the electrode array without surgical complications and are developing age-appropriate auditory perception and oral language skills. Early implantation is feasible and beneficial in some children who are younger than 12 months and should be considered with attention to variables involved in the decision-making process, including possible increased surgical risk, skull size and scalp thickness, and mastoid development.

MED‐EL Combi40+ Cochlear Implantation in Adults

Cochlear implantation is currently the treatment of choice for severe to profound sensorineural hearing loss. The MED-EL Combi40+ (Innsbruck, Austria) cochlear implant system was approved for use in the United States in 2001. This device employs a 31-mm-long electrode array, ceramic case, and continuous interleaved sampling with Hilbert transformation for envelope extraction. A single institution's experience with the Combi40+ implant in adult patients was reviewed. Retrospective chart review. Medical-surgical and audiological data were collected from 112 patients who received a MED-EL Combi40+ cochlear implant between December 1998 and April 2004. The rate of surgical complications and speech perception testing results compared favorably with those of other cochlear implant systems. For postlingually deafened adults, mean CNC word, HINTQ, CUNY, and HINT + 10 dB signal-to-noise ratio scores after 1 year of implant usage were 54%, 87%, 96%, and 64%, respectively. Prelingually deafened adults also derived significant benefit, but plateau performance for these patients was well below that for patients with later onset of deafness and significant variability was seen in this group. Repeat implantation for suspected device malfunction was undertaken in seven cases (6% of devices) (mean duration of use, 28 +/- 12 mo) with ultimate resolution of the presenting problem. The study results support the safety and efficacy of cochlear implantation with the MED-EL Combi40+ cochlear implant system.

Role of Infant Vocal Development in Candidacy for and Efficacy of Cochlear Implantation

Previous research has documented the importance of audition in the development of typical infant vocalization. Of particular interest is the development of canonical babbling, which is related to mastery of the timing elements of speech. Children with severe to profound hearing loss who use hearing aids have demonstrated both delayed and deviant canonical babbling. The vocal development of 12 children has been followed as they have been considered for cochlear implantation. Nine of these children have undergone implantation, and 5 of these children have been followed for more than 1 year after implantation. On average, canonical babbling emerged at 6.5 months after implantation. The time frame in which some children developed words was accelerated in terms of length of auditory experience as compared with normal-hearing peers. Mature oral-motor development is likely the primary contributing factor in this time course. One child who received a cochlear implant began to babble with hearing aids. It is not known whether normal canonical babbling is sufficient evidence on which to base candidacy decisions; however, our data suggest that children who produce canonical babbling maintain and build upon those skills after implantation.

The Effectiveness of Cochlear Implants for Children With Prelingual Deafness

No longer considered an experimental procedure, cochlear implantation in young children with profound hearing loss has become almost commonplace. This paper reviews the efficacy of cochlear implantation in children with prelingual deafness. First, a brief introduction to cochlear implants is provided. Second, research regarding the effects of cochlear implantation in children with prelingual deafness on speech perception, speech production, and language development is reviewed. Finally, implications for early childhood educators are discussed.

Individual differences in effectiveness of cochlear implants

The efficacy of cochlear implants has been firmly established. However, the effectiveness of cochlear implants varies widely and is influenced by demographic and experiential factors. First, there are enormous individual differences in both adults and children. Some patients show large changes in speech perception whereas others show only modest gains. Second, age of implantation and length of deafness affect outcome measures. Younger children do better than older children and children who have been deaf for shorter periods of time do better than children who have been deaf for longer periods of time. Third, communication mode affects outcome measures. Children from ‘‘oral-only’’ environments do much better than children who use ‘‘total communication.’’ Fourth, there are no preimplant predictors of outcome performance. The underlying abilities and skills ‘‘emerge’’ after implantation. Finally, there are no differences among devices or processing strategies. The pattern of results suggests that processes such as perception, attention, learning, and memory may play an important role in explaining the enormous individual differences. Investigations of the content and flow of information in the central nervous system and interactions between sensory input and stored knowledge may provide new insights into individual differences. [Work supported by NIH-NIDCD Grants DC00012 and DC00111.]

Implant outcomes: Towards a mixed methodology for evaluating the efficacy of adult cochlear implant programmes

Studies concerned with the efficacy of cochlear implants have traditionally focused on measuring enhancements in speech perception associated with implantation. This paper reports the findings of a study concerned with qualitative and quantitative measures of psychosocial benefit associated with the adult cochlear implant programme. Cochlear implants enhanced implantees' interpersonal communication skills and social confidence, and were associated with a reduction in the user's social anxiety. Broader socioeconomic gains were not achieved by implantees, mainly because of an absence of adequate employment and community education programmes associated with implant programmes.