OBJECTIVETo study the characteristic of the cochlear hydrops analysis masking procedure (CHAMP) in normal adults, and to evaluate the diagnostic values of its parameters for membranous labyrinth hydrops.

METHODSTwenty otologically normal adults were recruited (male:female = 10:10), and their auditory brainstem responses (ABR) were obtained to six stimulus conditions using Bio-logic auditory evoked potential system: clicks presented alone (unmasked condition) and clicks presented with ipsilateral pink noise high-pass filtered at 8, 4, 2, 1, and 0.5 kHz respectively.

RESULTSThe wave V latency of ABR to the high-pass masking pink noise clicks were longer than ABR to clicks alone. The latency delays of wave V for clicks presented with ipsilateral pink noise high-pass filtered at 8, 4, 2, 1, and 0.5 kHz compared to clicks alone were (0.30 ± 0.18), (0.97 ± 0.43), (1.65 ± 0.64), (3.21 ± 0.56), (4.66 ± 0.37) ms respectively. The complex amplitude ratio between ABR to click + 0.5 kHz high-pass noise and click alone was 0.95 ± 0.11.

CONCLUSIONSCHAMP is a promising diagnostic method for membranous labyrinth hydrops, and the latency delay of wave V might be used as the normal criterion. The specificity of the complex amplitude ratio need further evaluation in clinical work.