RESUMO
Objective To explore different characteristics of the vertebral artery and basilar artery haemody-namics in different frequencies to provide a theoretical basis for clinical treatment .Methods 90 cases of sudden deaf-ness were induded and according to hearing curve ,the cases were divided into three groups with 30 cases for each while the control group had 30 subjects .All cases were examined by TCD ,the VA ,BA test .Results Compared with group of median and low frequency sudden deafness ,the abnormal blood flow rate were found with decreased hearing(P0 .05) .High frequency hearing loss compared with the con-trol group patients with sudden deafness had a clear abnormal velocity (P<0 .05) ,characterized by high velocity . There was no statistically significant difference in blood flow rate among low and median frequency group ,full-fre-quency group and control group except for Vs of BA in low and median frequency group .Conclusion Vertebral and basilar arterial circulation disorders had present more significance in the incidence of sudden deafness ,evident espe-cially in high and all frequency sudden deafness .Early initiation of TCD examination can understand the change of the vertebral and basilar artery hemodynamics ,providing high clinical application values .