Three-dimensional wideband absorbance immittance findings in young adults with large vestibular aqueduct syndrome

Objective:To investigate the effect of large vestibular aqueduct syndrome (LVAS) onmiddle ear sound transmission using wideband absorbance immittance (WAI).Methods:WAI results from young adult LVAS patients and normal adults werecompared.Results:Averaged energy absorbance (EA) at ambient and peak pressure in the LVASgroup showed differences to the normal group. Under ambient pressure, the averageEA of the LVAS group was significantly higher than the normal group at frequencies472–866 Hz and 6169–8000 Hz (p< .05) and lower at frequencies 1122–2520 Hz(p< .05). Under peak pressure, absorbance was increased at frequencies 515–728,841, and 6169–8000 Hz (p< .05) and decreased at 1122–1374 Hz and 1587–2448 Hz (p< .05). An investigation into the effect of external auditory canal pressureon EA across frequencies in the pressure–frequency domain, showed that EA dif-fered significantly in the low-frequency region of 707and 1000 Hz from 0 to200 daPa and 500 Hz at 50 daPa (p< .05). There was also a significant difference inEA between the two groups at 8000 Hz (p< .05) in the pressure range?200–300 daPa.Conclusion:WAI is a valuable tool to measure the effect of LVAS on middle earsound transmission. LVAS has a significant effect on EA at low and mid frequenciesunder ambient pressure, while the frequencies affected are mainly at low frequencieswhen positive pressure is presented.Level of Evidence:Level 3a.