A Study On Perception Of Plosives Phonemes In Hearing-Impaired Chirldren Based On MMN

The aim of this study is to figure out the recognition features of plosive phonemes of hearing-impaired children based on MMN and the influence of rehabilitation training for children’s brain plasticity. The main contents and results of this study includes:1. MMN test was conducted on 5 normal adults, getting the MMN of ka/pa, ka/ta, pa/ta, ta/pa four groups of phonemes.The results were analyzed to determine the feasibility of the method, and selected the pa/ba, pa/ka, pa/ta as a formal test stimulus.2. MMN test was conducted on 16 hearing-impaired children, getting the MMN of pa/ba, pa/ka, pa/ta three groups of phonemes, through analysis, we get the following results:(1) The elicitation of MMN of hearing-impaired children is 81.25%.(2) Individual MMN amplitude varies among hearing-impaired children. The coefficient of variation is greater than or equals to 72.38%. The incubation period, duration time, peak index are relatively stable. For hearing-impaired children, duration time and peak index are better evidence to estimate the acoustic features of plosive phonemes.(3) In MMN tests, when the difference of standard stimulus and new stimulus is very small, the pallium is not able to process the new stimulus which would push forward the incubation period.(4) MMN individual variation is quite large with good overall repeatability. The general trend consists with behavioral tests.3. Train the subjects who get the poor scores in auditory recognition test and then get thei MMN again, the results are as follows:With effective auditory recognition training, the acoustic recognition ability of hearing-impaired children has been improved. MMN form is also turning good. The brain plasticity of hearing-impaired children can be studied with ERP.The innovation of this paper lies in that it’s the first time to analy the phoneme recognition by event related potentials, and it makes up the blank of phoneme recognition in electrophysiological. In addition, this study can be further studied in the number of subjects, the breadth of the test content, the selection of parameters and so on.