ultimate voice call recorder call phone audio recorder with audio calls recording software phone call audio voice logger 8ch Ultimate voice recorder with ... THD(total harmonic distortion)≤2%Callers NumberFSK,DTMF FSK Modulation Logic 0:2200Hz±1%Call MonitorSignal Tone, Voice, Reversed Polarity ... .Logic 1:1200Hz±1%DTMF Code0~9,*,#,A,B,C,DDTM ...