Pathology in Different Sites of Auditory Pathway had Different Effects on the Central Masking / 听力学及言语疾病杂志

ABSTRACT

Objective To investigate the appropri ate changes of the central masking effect(CME) when there were pathologies in d ifferent segment of auditory pathway,so as to give some instructions in cli nical masking test. Methods We tested the subjects with one ear normal and th e other ear diseased. The diseased ears included conductive deafness in 30 ca ses?sensory deafness in 27 cases and retrocochlear deafness in 7 cases. Results The pure conductive deafness had very little effect on CME; secretory otistis media and chronic suppurative otistis medi a made CME lower than normal due to the secondary cochlear impairment .When su dden deafness companied with vertigo,CME appeared much higher than the normal and appeared great difference individually;but CME appeared lower than normal at other kinds of cochlear deafness ears.CME appeared differently at retrocochlear deafness ears. Conclusion Audiometry results should be corrected when th e masker higher than 40 dB EM,because the masker can make the CME higher than 5 dB in the conductive impairment ears.In the sudden de afness companied with vertigo ears,CMEs were too high and too individually to fi nd a suitable correction for PTT.Insert earphone should be used in measuring the air-conduction PTT,and bone-conduction PTT test might be given up.