[The normal values of multiple-frequency tympanometry in normal newborns].
OBJECTIVE
To discuss the multiple-frequency probe tones tympanograms and the normal ranges of admittance, susceptance and conductance in normal newborns.


METHODS
Tympanometries with 226 Hz, 678 Hz and 1000 Hz probe tones were obtained from newborn infants with normal TEOAE and DPOAE(55 infants, 110 ears), analysed multiple-frequency prone tones tympanograms and values of admittance, susceptance and conductance by using GSI-33 middle ear analyzer.


RESULTS
226 Hz tympanograms for admittance, susceptance and conductance main were W-shaped, the percentages were 90.0%, 99.1% and 85.5%. 678 Hz tympanograms for admittance, susceptance and conductance main were single-peaked, the percentages of single-peaked type were 62.7%, 77.3% and 62.7%, and the percentages of W-shaped type were 34.6%, 20.9% and 31.8%, had a little three-peaked type. 1000 Hz tympanograms for admittance, susceptance and conductance main were single-peaked, and percentages were 96.4%, 99.1% and 97.3%, and had a little W-shape type but no three-peaked type. There were significant differences between admittance and susceptance, susceptance and conductance in 226 Hz and 678 Hz probe tones tympanogram. There were significant differences between admittance and susceptance, susceptance and conductance, admittance and conductance in 1000 Hz probe tones tympanogram.


CONCLUSIONS
Multiple-frequency probe tones tympanograms and the normal ranges of admittance, susceptance and conductance of normal newborn infants is obtained, and 1000 Hz probe tone tympanometry is a sensitive test for function of middle ear in newborn infants.
Department of Clinical Audiology Center, Beijing Institute of Otolaryngology, Affiliated Beijing Tongren Hospital of Capital University of Medical Sciences, Beijing, 100005, China.
Lihui
L
Huang
Ruibang
R
Dai
Lingyan
L
Mo
Hui
H
Liu
Lei
L
Shi
Jinghong
J
Xing
Ying
Y
Ma
Bo
B
Liu
Liansheng
L
Guo
Demin
D
Han
D000158:Acoustic Impedance Tests / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D012016:Reference Values