Can anyone identify this sound the previous owner has replaced the turbo and actuator in September. The video is short but any help would be appreciated

http://youtu.be/jZ7xrLh04bs

 

Did the noise start recently or has it always been there?. It sounds a bit like turbo whistle from the exhaust after the DPF has been removed. Also check the boost piping for leaks, you may need to stick your head under the bonnet while someone revs the engine.