[A preliminary study on characteristics of wideband acoustic immittance in patients with Meniere's disease]

Objective:To explore the wideband absorbance characteristics of patients with Meniere's disease（MD）. Methods:Wideband acoustic immittance was performed in 52 patients with unilateral Meniere's disease（UMD） and 30 control subjects with normal hearing. All UMD patients underwent pure tone audiometry, 226 Hz acoustic immittance, wideband acoustic immittance, and gadolinium contrast MRI. Sixteen frequency points were chosen to analyze the wideband absorbance at ambient and peak pressure, and the subjects were grouped as UMD group vs. control group and asymptomatic group. The student's t-test was used to compare the absorbance difference between them. Results:Both at peak and ambient pressure, there was a significant difference between the MD group and control group at 1587 Hz, 2000 Hz, 2519 Hz, 3174 Hz, and 4000 Hz; the MD group was lower than the control group（P<0.05）; there were no differences between the asymptomatic group and the symptomatic group, there also was a significant difference between the asymptomatic group and control group at 1587-4000 Hz（P<0.05）. Conclusion:The wideband absorbance in MD patients was significantly reduced within the frequency range of 1587-4000 Hz, and wideband acoustic immittance seems to be cost-effective in predicting MD.

The usefulness of wideband absorbance in the diagnosis of otosclerosis

Objective: To compare wideband absorbance (WBA) patterns between ears with otosclerosis and normal hearing ears and to investigate if WBA findings could be useful in the diagnosis of otosclerosis.Design: WBA was obtained at 107 frequency samples ranging from 0.226 to 8 kHz (24 per octave). A T-test was performed to compare between WBA in ears with otosclerosis and in normal hearing ears. The ability of WBA to discriminate between the patients with otosclerosis from the normal hearing participants was tested with a receiver operating characteristics (ROC) curve analysis.Study sample: Thirty-five patients with otosclerosis (age 31-64) and thirty-five normal hearing volunteers (age 32-64).Results: In frequency range 0.432-1.059 kHz, mean WBA in otosclerosis was significantly lower than mean WBA in normal hearing ears and in frequency range 4.238-8 kHz mean WBA in otosclerosis was significantly higher than mean WBA in normal hearing ears. The ROC analysis revealed that ears with otosclerosis and normal hearing ears could be distinguished based on mean WBA in frequency range >0.5 ≤ 1 kHz (AUC = 0.673) and based on mean WBA in frequency range >4 ≤ 8 kHz (AUC = 0.769).Conclusion: Our results suggest that WBA findings in ears with otosclerosis differ from WBA findings in normal hearing ears.

[Study on the characters of wideband tympanometry in newborns with normal hearing]

Objective:The aim of this study is to establish the characteristic of wideband tympanometry (WBT) in neonates with normal hearing. Method:Ninety newborn babies (149 ears) who had received rooming in care and passed hearing screening were randomly selected to test WBT. The screening programme consisted of distortion product otoacoustic emissions (DPOAE) and tympanometry at 1 kHz. The eigenvalue of ear canal volume, middle ear resonance frequency and acoustic absorptivity were obtained initially to explore the influence of gender and mode of delivery on the eigenvalues. Result:①Ear canal volume: The ear canal volume varied within (0.50±0.12)ml. The statistically significant correlationwas observed between ear canal volume and gender as well as the way of delivery (P<0.01). ②Resonance frequency: the resonant frequency distributed from 128 Hz to 642 Hz (mean 328.2±125.76 Hz). No statistically significant correlation (P>0.05) was observed between resonance frequency and gender as well as the way of delivery. ③Frequency wideband absorbance function: the shape of the curve showed two peaks and two troughs. The three most values were located in 1 296 Hz, 2 000 Hz and 5 339 Hz. No statistically significant correlation (P>0.05) was observed between acoustic absorptivity and gender as well as way of delivery. Conclusion:Resonance frequency and frequency acoustic absorptivity functions of newborns are different from adults. It is necessary to establish the normal reference value of WBT for newborns in China in order to promote this technique in the clinic.