Carhart notch

Car·hart notch

(kahr'hahrt noch)
Isolated depression around 2000 Hz in the bone-conduction audiogram of patients with otosclerosis.
See: air-bone gap
See also: otosclerosis
References in periodicals archive ?
We also calculated the Carhart notch for each patient; this value represents the increase in the bone-conduction threshold with the largest depression at 2,000 Hz in the audiometric curve.
All patients fulfilling the inclusion criteria of being indigenous black South Africans with progressive painless conductive hearing loss without infection or trauma, normal tympanic membrane and the presence of a Carhart notch on the audiogram, were included.
If a patient with a normal bone conduction threshold, allowing for the Carhart notch, undergoes surgery, it is likely that any subsequent loss of auditory acuity is due to presbycusis or some other factor.