Middle-ear function with tympanic-membrane perforations. I. Measurements and mechanisms.

摘要: Sound transmission through ears with tympanic-membrane (TM) perforations is not well understood. Here, measurements on human-cadaver are reported that describe sound the middle ear experimentally produced perforations, which range from 0.5 to 5.0 mm in diameter. Three response variables were measured acoustic stimulation at TM: stapes velocity, middle-ear cavity pressure, and impedance TM. The stapes-velocity show cause frequency-dependent losses; low frequencies losses largest increase as perforation size increases. Measurements of pressure coupled indicate dominant mechanism for loss TM reduction difference across TM; changes TM-to-ossicular coupling generally contribute less than 5 dB loss. input frequencies, a approximates cavity; increases, similarity cavity’s extends higher frequencies. collection results suggests effects can be represented by path air-volume flow canal cavity. quantitative description perforation-induced may help clinicians determine, an perforation, whether poor hearing only or other pathology should expected.