There is provided a method of frequency assignment of wireless radio audio transmission systems having a plurality of wireless transmitters and at least one wireless receiver. The wireless transmitters can represent first wireless transmitters which in the switched-on condition can approach another wireless transmitter below an established minimum spacing and second wireless transmitters which in the switched-on condition cannot approach below the minimum spacing. The wireless transmitters serve for example to transmit an audio signal wirelessly to the at least one wireless receiver. The transmission frequencies of the first wireless transmitters are assigned having regard to possible intermodulation effects. The transmission frequencies of the second wireless transmitters are assigned having regard to the relative spatial distances of the second wireless transmitters relative to each other.