Communication system of a rescue vehicle, comprising a plurality of speech input channels (12,14,16,18,20,22; 112,114,116,118,120,122) and a plurality of speech output channels (26,28,30,32; 126,128,130,132,133), and an interface router connecting the plurality of speech input channels (12,14,16,18,20,22; 112,114,116,118,120,122) and the plurality of speech output channels (26,28,30,32; 126,128,130,132,133) in a way that each of the plurality of speech input channels (12,14,16,18,20,22; 112,114,116,118,120,122) is adapted to be linked to communicate with a plurality of the speech output channels (26,28,30,32; 126,128,130,132,133) at the same time irrespective of any compatibility between the speech input channel and speech output channels to be linked, wherein two or more of the input channels (12,14,16,18,20,22; 112,114,116,118,120,122) comprise a microphone as a speech input source, with different microphones being located at different operator stands of the rescue vehicle, and wherein the speech output channels are located at different operator stands of the rescue vehicle, and wherein the interface router is connected to an internal bus system of the vehicle, characterized in that the communication system further comprises: - a microcontroller for controlling the interface router , connected to the internal bus system for receiving control commands transmitted via the internal bus system ; and - control command generation means connected to the internal bus system , with different control command generation means being located at different operator stands of the rescue vehicle, the control command generation means comprising at least one selection key at each of the operator stands, adapted for selecting one or more of the plurality of output channels (26,28,30,32; 126,128,130,132,133) as receivers for a speech message inputted via the microphone located at the respective operator stand, so that said speech message can be routed to the selected one or more output channels corresponding to other operator stands. and wherein the interface router is connected to an internal bus system of the vehicle, characterized in that the communication system further comprises: - a microcontroller for controlling the interface router , connected to the internal bus system for receiving control commands transmitted via the internal bus system ; and - control command generation means connected to the internal bus system , with different control command generation means being located at different operator stands of the rescue vehicle, the control command generation means comprising at least one selection key at each of the operator stands, adapted for selecting one or more of the plurality of output channels (26,28,30,32; 126,128,130,132,133) as receivers for a speech message inputted via the microphone located at the respective operator stand, so that said speech message can be routed to the selected one or more output channels corresponding to other operator stands. - a microcontroller for controlling the interface router , connected to the internal bus system for receiving control commands transmitted via the internal bus system ; and - control command generation means connected to the internal bus system , with different control command generation means being located at different operator stands of the rescue vehicle, the control command generation means comprising at least one selection key at each of the operator stands, adapted for selecting one or more of the plurality of output channels (26,28,30,32; 126,128,130,132,133) as receivers for a speech message inputted via the microphone located at the respective operator stand, so that said speech message can be routed to the selected one or more output channels corresponding to other operator stands. <EOS>