in order correspondingly to subject the inlet stage of the compressor part 3 to sound waves uniformly the question of whether the arrangement of the sound transmitters 13a b is undertaken as is shown in fig4 on the inner wall of the air inlet 7 and or on the outer wall depends on the respective individual case in the example represented the use of sound transmitters is not however limited to the air inlet 7 of the compressor part 3 the inlet stage of the turbine part 2 which is directly subjected to the hot combustion gases from the combustion chamber 4 is also subject to an increased danger of deposits it is therefore expedient to install sound transmitters 10a b there as well in particular at the turbine inlet 5 in addition further sound transmitters 11a b and 12a b as well as 8a b and 9a b can be advantageously arranged in the individual stages of the compressor part 3 and the turbine part 2 these further sound transmitters also keep the rear stages of the compressor part and the turbine part free from deposits or free them from deposits here again the arrangement of the transmitters in the individual case depends strongly on the respective geometry and the flow and thermodynamic conditions within the machine the sound.