Laitakari K, Löppönen H
Department of Otolaryngology, University of Oulu, Finland.
Scand Audiol. 1994;23(2):139-41. doi: 10.3109/01050399409047499.
The Carhart notch is a depression in the bone-conduction audiogram of patients with clinical otosclerosis. The middle frequencies from 0.5 to 2 kHz, which correspond to the resonance frequency of the middle ear, can be substantially improved following successful stapes surgery. Twenty-nine consecutive patients with clinical otosclerosis were tested 2 weeks before and 7 months after stapes surgery with conventional air-conduction (AC) and bone-conduction (BC) audiometry and electric bone-conduction (EBC) audiometry using an Audimax 500 audiometer. The BC thresholds improved at 0.5-2.0 kHz corresponding to the Carhart notch. On average, the EBC thresholds remained more stable, showing no Carhart phenomenon, which supports the concept that EBC stimulation is not entirely equivalent to conventional BC audiometry, but has a different mode of action on the inner ear.
卡哈特切迹是临床耳硬化症患者骨导听力图上的一个凹陷。0.5至2千赫的中频对应于中耳的共振频率，在镫骨手术成功后可得到显著改善。对29例连续的临床耳硬化症患者在镫骨手术前2周和术后7个月进行了测试，使用奥迪马克斯500听力计进行传统气导（AC）和骨导（BC）听力测定以及电骨导（EBC）听力测定。对应于卡哈特切迹的0.5 - 2.0千赫处的骨导阈值有所改善。平均而言，电骨导阈值保持更稳定，未出现卡哈特现象，这支持了电骨导刺激并不完全等同于传统骨导听力测定，而是对内耳有不同作用方式的概念。
