The present invention relates to a method for audio signal processing in a vehicle. In order to allow simple and reliable echo cancellation for voice recognition during simultaneous reproduction of a multichannel audio source signal in a vehicle, a mono audio signal is generated on the basis of a multichannel audio source signal. The mono audio signal is limited to a frequency range between a prescribed lower frequency and a prescribed upper frequency, for example to a range from 100 Hz to 8 kHz. The limited mono audio signal is output via multiple loudspeakers in the vehicle. An influence of the limited mono audio signal that is output via the multiple loudspeakers on a voice audio signal received in the vehicle via a microphone is compensated for by means of the limited mono audio signal in an echo canceller.