A.1KHz頻率處的聲壓級(jí)為63dB B.900-1120Hz頻率范圍內(nèi)的聲壓級(jí)的和為63dB C.710-1400Hz頻帶范圍內(nèi)的聲壓級(jí)的和為63dB D.333Hz頻率處的聲壓級(jí)為63dB
A.7 B.8 C.9 D.10
A.250-500Hz,400-500Hz B.500-1000Hz,500-630Hz C.355-710Hz,430-560Hz D.430-560Hz,355-710Hz