Is it the external noise or the cabin noise? We changed the propeller on the plane I usually fly (Ikarus C42) a couple of years ago and the new one is extremely

Is it the external noise or the cabin noise? We changed the propeller on the plane I usually fly (Ikarus C42) a couple of years ago and the new one is extremely quiet as perceived from the ground, now the engine makes more noise than the propeller. In the cockpit the noise is lower overall, but I was never able to point to the engine or to the prop from that position.