LOUD AUDIO NOISE IN A B767 ASSUMED TO BE XMITTED TO THE ACFT AUDIO SYS BY A PAX ELECTRONIC DEVICE. SOUND STOPPED WHEN DEVICE WAS FOUND AND TURNED OFF.

Narrative

WE WERE NOTIFIED OF A LOUD HIGH FREQ NOISE COMING FROM THE CEILING IN BUSINESS CLASS. AFTER CHECKING SEVERAL POSSIBILITIES; WE FOUND THE PROB. A PAX LAPTOP COMPUTER WAS SOMEHOW CAUSING THE PROB. THE COMPUTER WAS NOT PLUGGED INTO ANY PORT AND WAS OPERATING ON ITS INTERNAL BATTERY. IT WAS XMITTING SOMEHOW AND THE NOISE WAS VERY LOUD. THE COMPUTER IS A TOSHIBA; MODEL PRT800U. I WOULD SUGGEST THAT IF CREWS HAVE A SIMILAR PROB; THAT THEY ASK ALL COMPUTERS TO BE TURNED OFF AND SEE IF THAT REMEDIES THE PROB. AGAIN; THE NOISE WAS EXTREMELY LOUD AND NO NOISE WAS COMING FROM THE COMPUTER ITSELF. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR SAID THAT THE NOISE WAS SO LOUD THAT PASSENGERS WERE MOVED FROM THE AREA TO THE COACH CABIN. THE NOISE MOVED WITH THE PASSENGERS; HOWEVER IT APPEARED TO BE COMING FROM OVERHEAD IN THE CABIN. CONSULTATION WITH ACR MNTNC SUGGESTED THAT THE NOISE WAS COMING FROM THE ENTERTAINMENT SYS. THOSE SYSTEMS WERE DEACTIVATED WITH NO POSITIVE RESULT. A SEARCH WAS MADE FOR ELECTRONIC DEVICES. THE SOURCE OF THE XMISSION SEEMED TO BE THE RPTED TOSHIBA LAPTOP COMPUTER. MNTNC SUGGESTED THAT THERE MAY BE SOME SORT OF INTERFACE WITH THE SPEAKERS IN THE ACFT AND THE COMPUTER. THE NOISE STOPPED WHEN IT WAS TURNED OFF.