AAO-HNSF Certificate Program for Otolaryngology Personnel

Occlusion Effect

• An artificial improvement in low frequency threshold when the ear canals are covered • Occurs when testing bone conduction with the headphones/ inserts in the non-test ear • Occurs at 250 Hz, 500 Hz, and 1000 Hz • Additional masking noise is added to compensate

AAO-HNS/F

Certificate Program for Otolaryngology Personnel Workshop

31

Bone Conduction Masking

Effective masking is still 15 dB

500 Hz 250 Hz

1k Hz

2k Hz

4k Hz

Effective Masking

15 dB

15 dB

15 dB

15 dB

15 dB

Occlusion Effect

20 dB

15 dB

10 dB

0 dB

0 dB

35 dB

30 dB

25 dB

15 dB

15 dB

Start

AAO-HNS/F

Certificate Program for Otolaryngology Personnel Workshop

32

Bone Conduction Masking Hood (plateau) Method: 1. Find unmasked bone threshold

2. Add effective masking (15 dB) AND occlusion effect (if needed) to better ear and play beep at the bone level 3. If there is no change, increase masking by 5 dB 4. Play beep 5. If there is no change, increase masking by 5 dB 6. Play beep 7. If there is no change, increase masking by 5 dB 8. Play beep 9. Take masked threshold

AAO-HNS/F

Certificate Program for Otolaryngology Personnel Workshop

33