Normative values for tympanometry in 7-and 24-month-old children

The objective was to determine normative values Cor tympanometric variables for 7- and 24-month-old children and to assess the effect of various facto rs on these variables. Tympanometry was performed at scheduled health visit s at 7 and 24 months of age on children recruited to a prospective vaccine efficacy trial (n=2497 children at enrolment). Tympanograms obtained succes sfully from healthy ears with no recent otitis media were analysed. Normati ve values for static acoustic admittance (SAA). tympanometric peak pressure (TPP) and tympanometric width (TW) were calculated. The mean SAA was 0.25 cm(3) at the 7-month visit compared to 0.34 cm(3) at the 24-month visit. Th e TW decreased and TPP remained unchanged with age. Higher SAA values were found in boys. A history of recurrent acute otitis media and history or tym panostomy tubes were found to increase SAA and decrease TW at 24 months. In conclusion. age-specific normative values for interpretation of SAA and TW are necessary.