ABSTRACT
Objective To study the audiological characteristics of large vestibular aqueduct syndrome (LVAS)and provide evidence for early diagnosis and prevention.Methods Tympanometry,Otoacoustic emission , auditory brainstem response (ABR),auditory steady-state response(ASSR)were performed on the 49 cases of LVAS which were diagnosed by CT scanning from May,2010 to October,2013.Among them,23 cases(46ears)were examined by pure tone andiometry at the same time.ResuIts Pure tone andiometry showed that 33 ears were mixed hearing loss in the 23 cases(46 ears),the air-bone gap was larger at low frequencies than that of at high frequen-cies,15 ears were senserineural hearing loss with no air-bone gap;96 ears were type A tympanogram.Acoustic re-flex were present in 5 ears ;34 cases (68 ears)of LVAS group were detected with ASNR in 3 -4 ms by the ABR testing,the positive rate was 70.8%.ConcIusion Our study indicates that for confirmed LAVS,if the pure tone andiometry shows significant air-bone gaps at low frequencies with the normal tympanograms,and ASNR is e-voked during the routine ABR testing.