On Bekesy audiometry, a patient's CONTINUOUS tone tracing gradually separates from the PULSED tone tracing after about 1000 Hz, dipping 15 dB below it for the higher frequencies. This pattern corresponds to which Bekesy type and lesion?

• A Type II, cochlear hearing loss ✓
• B Type I, normal hearing or conductive loss
• C Type III, retrocochlear hearing loss
• D Type IV, functional hearing loss

Explanation

Bekesy Type II shows the continuous tracing falling away from the pulsed tracing by roughly 10 to 20 dB above 1000 Hz, caused by rapid adaptation of impaired cochlear hair cells to a steady tone. Type III shows continuous tracing dropping off completely, more than 25 dB and widening, which is the retrocochlear pattern. Type I shows complete overlap throughout.

Reference: Dhingra's Diseases of Ear, Nose and Throat, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.