Table 1.

Criteria used for audiologic improvement defined by Furahashi.¹⁴

Complete recovery	PTA 25 ≤ dB or identical to the contralateral, non-affected ear
Marked improvement	PTA improvement > 30 dB
Slight improvement	PTA improvement between 10 and 30 dB
Non-recovery	PTA improvement < 10 dB

PTA, four frequency pure-tone average (500, 1000, 2000, 4000 Hz).