BASIC SOUND PERCEPTION TO FORMULATE SPEECH PERCEPTION

Abstract

The aim of this study is to investigate the development of sound perception in hearing children. The subjects were 57 children aged 1 through 4 years old in the first experiment, 477 children aged 1 through 3 years old in the census and 20 mentally retarded children aged 7 through 16 years old whose mean MA were 4.4 years in the second experiment. Here, sound perception means how infants can correspond an input sound stimulus to output sound stimulus using an input-output circuit in their sensory organs. There were two sound perception tests. One was a word repetition test used with their auditory-articulatory circuit; the second was tapping the castanets which used their visual, auditory-hand circuit, and auditory-hand circuit. Response was evaluated as follows: If children respond to the same number of sound corresponding to input sound stimulus, the response was evaluated as a right response. In the word repetition test, the number of beats which was included in each syllable was evaluated. So in this case, a pronunciation of each phoneme was not evaluated. Results were as follows: In the word repetition test (auditory-articulatory circuit), 18-23 months children can perceive the 2 beats, 24-30 months children 4 beats, 31-35 months children 5 beats. And in the tapping test (visual, auditory-hand circuit), 18-30 months children can perceive 2 beats, 31-41 months children 3 beats, 42-47 months children 4 beats. In another tapping test (auditory-hand circuit), 24-30 months children can perceive 1 beat, 31-35 months children 2 beats, 36-41 months childsen 3 beats, 42-47 months children 4 beats. The same effects of above 3 tests were observed in the census of 477 children. Correlations of the sound perception abilities between each circuit (3 circuits) are highly correspondence. High correlations (0.86-0.66) are observed before 24 months hearing children. The same tendency of effects is observed on mental retardation (0.72-0.42). With consideration of motor development of infants and this effects, these findings reveal to us that, before children learn to discriminate the sound of phonome using auditory-articulatrry circut, they learn to perceive the beats corresponding with their body-movement (tapping was used in this study). These sound perception abilities are considered as basic abilities which are indispensable to formulate the phoneme discrimination abilities. This effect is a very significant finding for the formation of speech and auditory training for infants who can't speak.