Monitoring middle ear pressure by tympanometry. A study of middle ear pressure variation through seven hours.

The aim of this investigation was to monitor fluctuations in middle ear pressure, to study tympanometric signs of Eustachian tube functioning and to assess the validity of the tympanometric readings. In 20 patients with a low initial middle ear pressure (-150 daPa or lower) and 5 normals, impedance tympanometry was performed every 3 min through 7 h. Median pressure for the patients was -150 daPa (range 100 to -400 daPa) and for the normals 0 daPa (range 50 to -50 daPa).

Tympanometry in three-year-old children. I. A regional prevalence study on the distribution of tympanometric results in a non-selected population of 3-year-old children.

Epidemiological data on middle-ear pathology during pre-school age are lacking the striking frequency of middle-ear symptoms in this age group. To evaluate the applicability of the impedance test in the younger age groups and to make an epidemiological study of the distribution of tympanogram types in a normal group of pre-school children, an attempt was made to examine all 523 3-year-olds in a limited geographic area. 1005 ears in 504 children (96.