2016 ESPO Congress
Auditory and language development in Mandarin-speaking children after cochlear implantation

https://doi.org/10.1016/j.ijporl.2018.02.006Get rights and content

Abstract

Objective

To evaluate early auditory performance, speech perception and language skills in Mandarin-speaking prelingual deaf children in the first two years after they received a cochlear implant (CI) and analyse the effects of possible associated factors.

Methods

The Infant-Toddler Meaningful Auditory Integration Scale (ITMAIS)/Meaningful Auditory Integration Scale (MAIS), Mandarin Early Speech Perception (MESP) test and Putonghua Communicative Development Inventory (PCDI) were used to assess auditory and language outcomes in 132 Mandarin-speaking children pre- and post-implantation.

Results

Children with CIs exhibited an ITMAIS/MAIS and PCDI developmental trajectory similar to that of children with normal hearing. The increased number of participants who achieved MESP categories 1–6 at each test interval showed a significant improvement in speech perception by paediatric CI recipients. Age at implantation and socioeconomic status were consistently associated with both auditory and language outcomes in the first two years post-implantation.

Conclusion

Mandarin-speaking children with CIs exhibit significant improvements in early auditory and language development. Though these improvements followed the normative developmental trajectories, they still exhibited a gap compared with normative values. Earlier implantation and higher socioeconomic status are consistent predictors of greater auditory and language skills in the early stage.

Introduction

Since the first cochlear implant (CI) was successfully implanted in a paediatric patient in China 20 years ago, the total number of paediatric CI users has reached more than 50,000 and increases every year. One of the most direct ways to demonstrate the benefit of a CI is to evaluate the patient's progress in speech perception and language production. As early speech perception and language skills post-implantation play a predictive role in subsequent language outcomes [1], it is important to evaluate the early auditory and language levels of paediatric CI users both for a clinical reference and to identify individuals with auditory or language development problems.

Due to the relatively recent availability of testing materials in Mandarin and the limited measures appropriate for Mandarin-speaking children, data on the early stages of auditory and language development in children with CIs remain sparse. Few studies have focused on whether the early auditory and language developmental trajectories of children with CIs are similar to those exhibited by children with normal hearing or whether the auditory and language performance of children with CIs compares favourably with that of children with normal hearing, who serve as the gold standard for comparison. Comparisons between the early performance of children with CIs and the performance of normal-hearing children can be used to provide appropriate expectations as well as suggest evidence-based rehabilitation schedules during the early stage after implantation.

In such comparisons, a major methodological challenge is the selection of test materials. Given the limited attention span and the developing cognitive level of the paediatric population, parental questionnaires are considered suitable methods to record information on these patients' early auditory and language development. The Infant-Toddler Meaningful Auditory Integration Scale (ITMAIS) [2] and the Meaningful Auditory Integration Scale (MAIS) [3] are both widely used and consist of structured parental interviews that primarily assess sound awareness and sound recognition abilities in everyday situations. Zheng et al. [4] translated these two questionnaires into Chinese and conducted a normative study, which provides the normative trajectory and allows for a comparison between children with CIs and children with normal hearing. Speech perception and recognition are viewed as the gold standard for evaluating hearing skills; therefore, speech audiometry is essential in auditory assessments. The Mandarin Early Speech Perception (MESP) [5] test is a closed-set word test that can be introduced when the subject is able to choose between two options or is older than the age of two. To assess early language development, the Putonghua Communicative Development Inventory (PCDI) [6] can be adopted to evaluate the receptive and expressive vocabulary of children with normal hearing as well as those with delayed language skills.

Although CIs have been shown to be an effective therapy for prelingual deaf children to rebuild auditory sensations and progress in speech perception and language production, individual differences in rehabilitation outcomes remain high. A large number of child-related and environmental factors affect the early development of speech perception and language skills after implantation. Age at implantation, duration of implant use, preoperative residual hearing, hearing aid experience, educational placement, family socioeconomic status, and communication mode, among other factors, are considered possible associated factors. Some studies focused on the predictors of early auditory and language outcomes at one specific moment. However, it is likely that the effect of a factor may change over time and differ between outcome measures.

The objectives of the current study were (1) to evaluate the early auditory performance, speech perception and language skills developed by Mandarin-speaking prelingual deaf children over the first two years after implantation and compare their results with those of children with normal hearing and (2) to examine the possible factors contributing to auditory and language skills one and two years post-implantation.

Section snippets

Subjects

A consecutive sample of 132 prelingual deaf children who received a unilateral CI between the ages of 8 months and 7 years in our department were recruited using the following inclusion criteria: (1) prelingual severe to profound sensorineural hearing loss with the exception of inner ear malformations and cochlear nerve deficiencies, (2) rehabilitation training was received for at least one year after implantation, (3) the native language was Mandarin Chinese, (4) oral communication was the

ITMAIS and MAIS scores

The numbers of subjects assessed using ITMAIS or MAIS at different test intervals were as follows: 62 and 70 at baseline, 49 and 83 at 3 months, 35 and 97 at 6 months, 24 and 108 at 9 months, 15 and 117 at 12 months, 7 and 125 at 18 months and 2 and 130 at 24 months after activation, respectively. The percentage scores from the ITMAIS and MAIS were combined for analysis, as the two scales have the same last 8 items intended to assess the same ability. The black solid line in Fig. 1 shows the

Discussion

Several major characteristics of early auditory development were shown in this early stage analysis of a sample of Mandarin-speaking children with CIs from our centre. First, the developmental trajectory of auditory ability was not symmetrical during the first two years of CI use, improving rapidly in the first year, especially in the first 6 months and slowing down in the second year. Second, the progress rate in two aspects of auditory ability—sound detection and sound recognition—developed

Conclusions

In summary, we report significant improvements in early auditory performance and language skills developed by Mandarin-speaking children with CIs. Though these improvements followed the normative developmental trajectories, children with CIs still exhibited a gap compared with normative values. Earlier implantation and higher socioeconomic status are consistent predictors of auditory and language skills in the early stage.

Declarations of interest

None.

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