RESUMO
Objective To study breathing characteristics of normal children of 6～7 years old when speaking in a normal manner.Methods RM 6240 physiological signal collection and processing system and Hx 100 respiratory transducer were used to collect the average peak expiratory pressure,inspiratory valley pressure,respiratory rate,respiratory depth from 160 normally speaking children.Results When speaking,the average peak expiratory pressure,inspiratory valley pressure,respiratory rate and respiratory depth of chest were all significantly increased (P<0.01);while that of abdomen was all reduced(P<0.05,P<0.01)except for respiratory rate(P<0.05)which was increased.In both respiratory conditions,all the data of abdomen were significantly larger than thaf of chest(P<0.01);all the data of boys were larger than that of girls(P<0.05,P<0.01).Conclusion When speaking,it involves thoraco-abdominal breathing,and the increase of chest activity will increase the volume of inhaled air.The increase of abdominal activity is for better control of respiratory airflow.Abdominal breathing plays a main role in normal speaking.Boys'respiratory muscles,respiratory organs are developed better than girls.