• What is the type of loss in the left ear?
• What is the occlusion effect?
• Does a patient with conductive loss have an additional occlusion effect if the ear with the conductive loss  is occluded while conducting bone conduction testing?
• Note that bone conduction testing was not obtained for the right ear.  If the audiologist were going to test bone for the right ear, masking noise would have to be put into the left ear.  At 250 Hz, the right ear bone conduction score might be anything from zero to 25 dB HL.  Let’s assume that the real threshold is 0 dB HL.  How much noise would be needed in the right ear in order to make sure that the left ear cochlea doesn’t hear the 0 dB HL tone? Specifically, if the audiologist puts in 70 dB of effective masking in the left ear by air conduction, how loud would it be at the left ear’s cochlea, and would that mask a 0 dB HL crossed-over tone?
• If 70 dB of effective masking is put into the left ear, how much could cross back to the right cochlea if the patient has an interaural attenuation value of 50 dB?  Would that cross-back cause the patient not to hear the 0 dB HL tone presented to the right cochlea?

If you did your calculations and logic correctly, you will see that there is a masking dilemma at 250 Hz for bone conduction testing.  You may want to see if there is a right 250 Hz air-bone gap, but you can’t.

• The hearing loss is not as severe in the mid frequencies, so over masking would be less likely to be problematic.  Should the audiologist test right ear bone conduction thresholds in the middle frequencies?
• Do you think there is some hearing loss in the right ear, or would you conclude it is more likely that the middle ear is entirely normal?  Would unmasked right bone conduction testing be helpful or not?
• How do you think this child’s hearing is affected by the loss?
• Compare the pure tone average and the spondee thresholds.  Comment.