A.500~2000Hz B.500~3000Hz C.250~2000Hz D.250~500Hz E.2000~4000Hz
A.0.1% B.0.3% C.1% D.5% E.10%
A.痛閾 B.聲強(qiáng)級 C.響度 D.感覺閾 E.聽閾