When traveling by air, it's common to hear bells, chimes, tones, whatever-you-call-them over the speaker system. It seems like a single tone is just a passenger pushing their call button. But what do the other ones mean? Are they unique to each airline, or are they universal country-wide or world-wide?
Right, firstly according to Airliners.net forums, each airline has different chime meanings.
However, on Yahoo, we have a list of all of the chimes - but presumably it's for a specific plane, and it doesn't say which:
Generally they are as follows:-
1 x chime for a passenger call bell
2 x chimes if the crew are calling each other
2 x chimes to indicate takeoff and landing
5 x hi / low chimes an emergency!!!
2x bong!! for the seatbelt sign flashing for top of climb for crew to be released and same again for crew to be seated for landing!
3x Chimes if toilet smoke detector activated
1x Chime for toilet call bell 1x HIGH, HIGH LOW Chime for emergency Interphone call to Manager
1x LOW LOW HIGH Chime for Crew help needed!
If you listen carefully the are two tones of call chime. A high and a low. These will vary depending on operator and aircraft type!
This is confirmed again on Airlines.net, where they show that for Canadian Airlines it's as follows:
1 bell - passenger call, lav call, change in cabin signs, five minute warning prior to landing, crew communication via interphone
2 bells - F/A to contact the flight deck for a message
3 bells - Take-off or landing imminent - take your jump seat
5 bells on the ground - evacuate
5 bells inflight - F/A to report immediately to the flight deck to receive emergency instructions
The same forums have another page with information on NW, Continental and others, so it would certainly seem to vary from company to company.