Intraoral air pressure during the production of /p/ and /b/ by children, youths, and adults.

Peak intraoral air pressures produced by 12 children (age four to six years), 12 youths (age 10 to 12 years), and 12 adults (age 19 to 46 years) were measured during the production of /p/ and /b/ in 12 stimulus words placed in a carrier phrase. Mean pressures produced by children and youths were similar but significantly higher than those for adults. Pressures associated with /p/ were significantly higher than those associated with /b/ across all age groups. Mean pressures associated with the intervocalic context were significantly higher than for the postvocalic context. An inverse relationship was found between age and variability of intraoral pressure, and the variability of pressure associated with /b/ was greater across all age groups than that associated with /p/.