In order to prevent the secret recording without consent from leaking or infringing privacy, the recording truncator which can effectively truncate digital and tape recorders and listeners has come out. The recording truncator can effectively truncate the digital recording pen and tape recorder whose pickup frequency is between 100 HZ and 20 000 HZ. Only a piece of noise is recorded by a recording pen or a recorder. It is impossible to record the content of the speaker's conversation at all. The recorded voice can not restore the speaker's voice after sound processing. Thus, the conversation content can be effectively protected from secret recording.
