as mentioned in another post, going the ANR route is a simple relatively inexpensive way to reduce cockpit noise.  I sent my Peltier 7003's to Headsets Inc, Amarillo TX, who adapted them with their kit.  Total price for two was under $500 and they work well..  Didn't realise how much difference they made..  They retrofit other brands too...Regards  Don Skeele  N320J   235/320