Which of the following audiometric findings is characteristic of conductive hearing loss?

Explanation

## Conductive vs Sensorineural Hearing Loss on Audiogram **Key Point:** In conductive hearing loss, bone conduction (BC) thresholds remain normal while air conduction (AC) thresholds are elevated, creating an air-bone gap (ABG) where AC > BC. ### Audiometric Patterns | Feature | Conductive HL | Sensorineural HL | | --- | --- | --- | | Air conduction (AC) | Elevated (worse) | Elevated (worse) | | Bone conduction (BC) | Normal | Elevated (worse) | | Air-bone gap | Present (AC > BC) | Absent (AC ≈ BC) | | Pattern | Horizontal or rising | High-frequency sloping | **High-Yield:** The hallmark of conductive hearing loss is that the inner ear (cochlea) functions normally, so bone conduction bypasses the conductive pathway and reaches the cochlea unimpeded. This results in better bone conduction thresholds compared to air conduction thresholds. **Clinical Pearl:** A Carhart notch (bone conduction dip at 2000 Hz) is actually seen in otosclerosis, a form of conductive hearing loss, but it is NOT the defining characteristic—the air-bone gap is. **Mnemonic:** **ABC-D** = Air-Bone gap = Conductive; Diminished bone conduction = sensorineural.