In a normal hearing audiogram, which combination of air conduction (AC), bone conduction (BC), and air-bone gap is expected?

• A. AC: abnormal; BC: abnormal; No air-bone gap
• B. AC: normal; BC: abnormal; No air-bone gap
• C. AC: normal; BC: normal; No air-bone gap
• D. AC: normal; BC: normal; Air-bone gap present

Answer: (C)

In a normal-hearing ear, both air conduction and bone conduction thresholds sit within normal limits (typically 0–20 dB HL) and they line up closely with each other, so there is no air-bone gap. The absence of a gap means the conductive pathways (outer/middle ear) and the sensorineural pathways (inner ear and beyond) are all functioning well.

So the combination that fits a normal audiogram is AC normal, BC normal, with no air-bone gap. If either AC or BC were outside the normal range, or if AC and BC differed by a noticeable gap, that would indicate some degree of hearing loss or a conductive issue, which isn’t the case here.