Narrative:

While in cruise flight at altitude in the middle of night and in the middle of the pacific; the door entry horn sounded. It is very faint in flight. I turned around and was prepared to keep the cockpit secure. I saw that it was our first flight attendant. He said that they had been trying to call us but the bells in the cockpit were not working. We looked around and found that the handset at the back of the center console was slightly out of its cradle. I was not aware that that silences all the call chimes in the cockpit. We then had the flight attendants call us with the cockpit handset secured and off the hook and determined that it indeed does cut out the cockpit chimes when off the hook. We flew on and landed as planned. The flight was normal. The man on the phone that asked for the report said there was some issue with my headset. I don't know what that is about. I was wearing the same headset that I have used for the last seven years; including all the check rides and flights with chief pilots and check airmen. I have a noise canceling aviation headset. It works great. It protects my hearing and makes the HF radio clear and understandable. It was plugged into the headset plugs in the airplane and I was monitoring 123.45 and 121.5.

Google
 

Original NASA ASRS Text

Title: B757-200 flight crew is surprised to see the a Flight Attendant entering the cockpit to check on their welfare during a night flight over the Pacific. The call bells were muted due to the handset not being in its' cradle and both pilots were wearing noise canceling headsets masking the door chimes.

Narrative: While in cruise flight at altitude in the middle of night and in the middle of the Pacific; the door entry horn sounded. It is very faint in flight. I turned around and was prepared to keep the cockpit secure. I saw that it was our First Flight Attendant. He said that they had been trying to call us but the bells in the cockpit were not working. We looked around and found that the handset at the back of the center console was slightly out of its cradle. I was not aware that that silences all the call chimes in the cockpit. We then had the flight attendants call us with the cockpit handset secured and off the hook and determined that it indeed does cut out the cockpit chimes when off the hook. We flew on and landed as planned. The flight was normal. The man on the phone that asked for the report said there was some issue with my headset. I don't know what that is about. I was wearing the same headset that I have used for the last seven years; including all the check rides and flights with chief pilots and check airmen. I have a noise canceling aviation headset. It works great. It protects my hearing and makes the HF radio clear and understandable. It was plugged into the headset plugs in the airplane and I was monitoring 123.45 and 121.5.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.