VOCALIZATION AND BREATHING DURING THE 2ND AND 3RD YEARS OF LIFE

Vocalization and breathing were studied in 40 healthy young children, including 5 boys and 5 girls at each, of ages of 18, 24, 30, and 36 mo nths. A variable inductance plethysmograph was used to obtain estimate s of volume changes of the rib cage, abdomen, and lung, as well as est imates of selected temporal features of the breathing cycle. Results i ndicated that breathing behavior was influenced by height and age, but not by vocalization type or sex. Such behavior was found to be highly variable, demonstrating that these young children had multiple degree s of freedom of performance available to accomplish the aeromechanical drive required.