Method for suppressing sound and a circuit arrangement and sound-protection device to carry out the method

摘要

In a method and device for suppressing sound, an interfering sound emitted from a source is picked up by a sound recorder (10; 74; 96). The interfering sound signal which is converted by the sound recorder into an electric signal is split in a branching circuit (12) over three separate signal paths. In the first signal path (14), the signal is passed through a low-pass filter and subjected to a phase shift of 180 DEG . In the second signal path (20), it is also passed through a low-pass filter and furthermore subjected to a delay. On the third signal path (26), specific required signals can be transmitted in unmodified form via a bandpass filter arrangement (28). All three signal paths are combined in a unifying network (30) to form a composite signal (32) which activates a sound transmitter (34; 70; 100). The compensation sound generated by the sound transmitter (34; 70; 100) is added to the interfering sound so that they cancel one another. <IMAGE>