I switched from a set of DC 13.4s to Zulu 1s part way through my training. I think the Zulus with ANR operational are a bit quieter than the DCs –*with the added benefit of bluetooth. But yes, the noise level when the batteries run out on the Zulus is pretty atrocious so make sure you keep spare batteries at hand. I've had the batteries run out on two flights: my PPL flight test and my CPL flight test. What luck!