Which statement accurately describes the occlusion effect observed during bone-conduction testing?

Which statement accurately describes the occlusion effect observed during bone-conduction testing?

• A. It results in artificially poorer thresholds at all frequencies.
• B. It can affect the measurement of air-conduction thresholds at low frequencies.
• C. It can affect the measurement of bone-conduction thresholds at high frequencies.
• D. It can affect the measurement of bone-conduction thresholds at low frequencies.

Answer: (D)

The occlusion effect is the change in bone-conduction thresholds that occurs when the ear canal is blocked. It is most pronounced at low frequencies, because occluding the canal reduces the escape of acoustic energy and increases the pressure transmitted to the inner ear from bone-conducted vibrations. This makes bone-conduction thresholds appear artificially better (lower) at low frequencies. So, it can affect bone-conduction measurements at low frequencies, while high-frequency bone-conduction thresholds are not notably impacted and air-conduction thresholds aren’t the focus of this effect.

The occlusion effect is the change in bone-conduction thresholds that occurs when the ear canal is blocked. It is most pronounced at low frequencies, because occluding the canal reduces the escape of acoustic energy and increases the pressure transmitted to the inner ear from bone-conducted vibrations. This makes bone-conduction thresholds appear artificially better (lower) at low frequencies. So, it can affect bone-conduction measurements at low frequencies, while high-frequency bone-conduction thresholds are not notably impacted and air-conduction thresholds aren’t the focus of this effect.