Table III.

Hearing improvement as defined by the Ministry of Health and Welfare in Japan*.

Status	Criteria
Complete recovery	All five frequencies of final audiograms are 20 dB or less, or improvement to the same degree of hearing in the unaffected ear
Marked improvement	PTA improvement ≥30 dB
Slight improvement	10 dB ≤PTA improvement <30 dB
No change	PTA improvement <10 dB

PTA, arithmetic mean of the five frequencies; the five frequencies are 250, 500, 1000, 2000, and 4000 Hz.

*These criteria were established in 1988.