[Wide band tympanometry energy reflectance in Chinese infants and children with normal outer and middle ears]
Yibo Lei1, Wei Lu, Lingyan Mo2
1Department of Otology, First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China.
Objective:
To explore the law of wide band tympanometry energy reflectance (WBTER) in Chinese infants of Han nationality with normal outer and middle ears, and to provide the normal values for the clinical application of WBTER.
Methods:
Ninety four infants (170 ears) of Han nationality with normal outer and middle ears evidenced by temporal bone CT, and 226 Hz and 1 000 Hz tympanometry at the ages between three and 48 months (median age: 14 months) were selected and divided into four groups: 3-6 months (32 ears), 7-12 months (53 ears), 13-24 months (46 ears) and 25-48 months (39 ears). WBTER was conducted on these infants, and the basic law of energy reflectance under different frequencies, as well as the influence of age on energy reflectance were analyzed using SPSS 15.0.
Results:
The normal value of energy reflectance was higher at low frequency, gradually decreased with the increase of frequency, reached the minimum near 4 000 Hz , followed by constantly increased till 8 000 Hz. In the scope of frequency below 1 000 Hz and above 6 350 Hz, the energy reflectance values of infants in the group of 3-6 months were significantly lower than those of infants in other age groups (P < 0.05). In comparison to the group below six months, the groups over six months generally had higher energy reflectance and lower fluctuation.
Conclusions:
The pattern of energy reflectance across frequency range for Chinese infants and children was consistent with that of other races reported in foreign countries. The WBTER changes with the growing of age, which tends to be stable after the first six months of birth.
