to strengthen schaltungseinrichtung composition in the presence of an external störgeräusches nutzsignale

摘要

The amplifying circuit is used to amplify useful electro-acoustic signals, in the presence of an external interference noise in the listening area of the reproduced sounds e.g. due to road traffic, aircraft noise etc. A transfer circuit (17) is selectively inserted in the signal path, the frequency of which is tuned in accordance with the frequency spectrum of the interference noise. Preferably a dynamic compressor (14) is also selectively inserted in the signal path, and the transfer circuit (17) has an amplification factor for each frequency determined by the interference noise level for this frequency.