The 500 Hz ABR shows a cochlear microphonic although stimulus artifact may also be present.

• What significance, if any, do you attach to the finding of a 500 Hz cochlear microphonic?

The 4000 Hz ABR thresholds are shown below.  Note that wave I is evident at 60 dB nHL in the right ear, but V is not seen.  Given that the click ABR showed more robust I than V this may not be a surprise.

• Does it have any implication for the interpretation of the results?

2000 Hz was also tested, but the traces are not particularly interesting.

The lowest levels eliciting an electrophysiological response from frequency specific toneburst stimuli are listed below:
.           Right Left
500 Hz    50      60
2000 Hz  70      80
4000 Hz  60      70

Evoked potential thresholds predict the following hearing thresholds

.           Right Left
500 Hz    30      40
2000 Hz  60      70
4000 Hz  50      60