Method and circuit for the adjustment of the level of sound sources in accordance with the ambient noise level

摘要

The invention relates to a method for adjusting the volume of a car radio to the ambient noise level, the AF signal level present behind a controlling element arranged in the AF signal path and the travelling noise signal being supplied to a control loop which attempts to minimise the difference between the AF signal and the travelling noise signal. So that the controlling element does not ramp up during a pause in the signal in the presence of a travelling noise level, an AF pause detector is provided which, by means of a variable threshold value, evaluates AF passages with low signal level as pauses and slowly drops the AF signal level during these pauses. IMAGE