Effect of age, gender, and repeated measures on intraoral air pressure in normal adults.

The effect of age, gender, and repeated measures on intraoral air pressure (P0) was examined. Sixty adults comprised of 10 males and 10 females in each of three age groups (i.e., 20-39, 40-59, and 60-83 years) participated. P0 was assessed during voiceless stop plosive /p/ productions in repeated vowel/consonant syllables. The three medial plosives of a seven-syllable train were averaged to comprise a token. Five tokens were obtained and averaged for each of three trials. Thus each participant contributed 105 syllables and a subsequent three P0s for analyses. There was no statistically significant difference in P0 as a function of age or gender (P > 0.05). These findings support the conception that P0 remains stable throughout adulthood and is not dependent on gender. Differences in repeated measures of P0 attained statistical significance (P = 0.03), however the mean differences between trials (0.23 cm H20) were negligible and deemed to be clinically insignificant. Thus, across a short sampling session, P0 is a relatively stable measurement and does not change as a function of age or gender.