A hearing system comprising a first hearing device and a second hearing device, wherein each of the first hearing device and the second hearing device comprises: a microphone; a processor for processing a signal from the microphone and for executing program code modules; an output device for outputting the processed signal to an ear of the user; a memory for storing program code modules to be executed by the processor, a program code module comprising executable code; a transceiver for exchanging data with another hearing device (12, 14); wherein in the memory of the first hearing device a first set of program code modules and in the memory of the second hearing device a second set of program code modules different from the first set is stored, the first set of program code modules and the second set of program code modules comprising different program code modules (56h to 56s); wherein the hearing system is adapted for: executing a first program code module (56a to 56m) from the first set of program code modules stored in the memory of the first hearing device with the processor of the first hearing device; sending a further program code module of the second set of program code modules from the second hearing device to the first hearing device upon request from the first hearing device or the second hearing device; executing the further program code module (56n to 56s) with the processor of the first hearing device; sending a second program code module (56h to 56m) from the first set of program code modules to the second hearing device; executing the second program code module (56h to 56m) with the processor of the second hearing device. a microphone; a processor for processing a signal from the microphone and for executing program code modules; an output device for outputting the processed signal to an ear of the user; a memory for storing program code modules to be executed by the processor, a program code module comprising executable code; a transceiver for exchanging data with another hearing device (12, 14); wherein in the memory of the first hearing device a first set of program code modules and in the memory of the second hearing device a second set of program code modules different from the first set is stored, the first set of program code modules and the second set of program code modules comprising different program code modules (56h to 56s); wherein the hearing system is adapted for: executing a first program code module (56a to 56m) from the first set of program code modules stored in the memory of the first hearing device with the processor of the first hearing device; sending a further program code module of the second set of program code modules from the second hearing device to the first hearing device upon request from the first hearing device or the second hearing device; executing the further program code module (56n to 56s) with the processor of the first hearing device; sending a second program code module (56h to 56m) from the first set of program code modules to the second hearing device; executing the second program code module (56h to 56m) with the processor of the second hearing device. executing a first program code module (56a to 56m) from the first set of program code modules stored in the memory of the first hearing device with the processor of the first hearing device; sending a further program code module of the second set of program code modules from the second hearing device to the first hearing device upon request from the first hearing device or the second hearing device; executing the further program code module (56n to 56s) with the processor of the first hearing device; sending a second program code module (56h to 56m) from the first set of program code modules to the second hearing device; executing the second program code module (56h to 56m) with the processor of the second hearing device.