1才未満乳児の聴力発達に関する研究

概要

論文の詳細を見る
The developmental processes of auditory conditioned response and hearing acuity in infants under one year of age, including newborns, were studied using a combination of pure tones through a loudspeaker and electric shocks of alternating current given on the left calf.An auditory screening test by observing unconditioned auditory responses to various noises was first established to select subjects with normal hearing.Some preliminary experiments were performed in order to establish this conditioned avoidance response audiometry.The results obtained are as follows:Most of the infants, except some one less than 2 months old, gave definite unconditioned responses to the pure tone of 500c.p.s.at 90db.All infants could be conditioned with a combination of pure tones and electric shocks.There were observed some difference in the acquisition, extinction and generalization of the conditioned response in infants of6-9 months old, particularly in infants of 6months old.Hearing acuity rose gradually with the increase of age.There were no great difference in hearing acuity in infants from 4 to 11 months of age. In conclusion, this conditioned avoidance res ponse audiometry is useful for evaluating hearing acuity in infants less than one year old.