B737-400 FLT CREW CLIMBED THROUGH ASSIGNED ALT. PF FAILED TO SET 29.92 DURING CLIMBOUT.

Narrative

WE WERE CLBING TO OUR ASSIGNED CRUISE ALT OF 34000 FT. WE GOT A CALL AT APPROX 33000 FT. I LOOKED AT THE MESSAGE; THE AUTOPLT WAS ENGAGED AND STARTED TO LEVEL THE PLANE OFF. THE FO WAS FLYING AND THE AUTOPLT WAS ON HIS SIDE. I LOOKED AT THE MESSAGE WHEN I LOOKED AT THE ALTIMETER; IT READ 34400 FT. I THEN ASKED THE FO WHAT HIS READ AND HE SAID 34000 FT. AT THIS TIME ZAN ASKED US OUR ALT. HE SHOWED US 400 FT HIGH. WE THEN REALIZED HIS ALTIMETER WAS STILL SET TO THE DEP ARPT. WE DSNDED TO 34000 FT. WHEN NEAR AN ASSIGNED ALT WATCH THE LEVELOFF. DON'T BOTH LOOK AT CDU. ALSO I WAS WEARING A STANDARD BOOM MIKE. FO HAD ON A NOISE CANCELING; AND SOMETIMES WE MISCOMMUNICATED. SUCH AS CLB CHK; 'ALTIMETERS 2992' WHICH WAS NOT CHKED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE REPORTER STATED THAT THE FLT DID RECEIVE AN ACARS MSG JUST PRIOR TO LEVELOFF. THE PNF'S ATTENTION WAS DIVERTED; CONFIDENT THAT THE PF WOULD LEVEL THE ACFT; SINCE THE AUTOPILOT WAS ENGAGED. ALTHOUGH THE CLIMB CHECK THROUGH TRANSITION ALT WAS THOUGHT TO HAVE BEEN COMPLETED; THE PF WAS USING AN UNAPPROVED NOISE-CANCELING HEADSET; AND MAY NOT HAVE HEARD THE CALLOUT. THE REPORTER IS CONCERNED THAT THE USE OF SUCH HEADSETS IS CREATING CONFUSION AND INHIBITS EFFECTIVE COMMUNICATION.