A.250Hz B.500Hz C.1000Hz D.2000Hz E.4000Hz
A.0.5~4kHz B.0.25~8kHz C.0.125~8kHz D.0.35~8kHz E.0.45~8kHz
A.90~120dB B.50~120dB C.60~110dB D.70~120dB E.80~120dB