| 摘要 |
An arrangement for suppressing periodic interferences in the transmission of signals from a signal source within a specific frequency range (2). The arrangement includes a signal emitting element that is subjected to interference or disturbance, such as a telecoil (8) or microphone (12), for instance. The signal source is coupled to a comb filter (9 and 15) of the stop-band type, which is adapted so that the stop band (1) of the filter coincides with the fundamental of the periodic interference and its harmonics within the frequency range (2) of the desired signal. The stop band has a bandwidth which is so small that the character of the desired signal will be influenced only to a negligible extent. The comb filter is implemented with the aid of a digital signal processor (9) of known design. This signal processor can be programmed to establish any occurrent periodic interference that includes harmonics and adapt the stop band of the comb filter (9 and 15) with respect to these harmonics. |
