That's true yes. Had to remove one out of the kitchen because it would trigger too easy. Put it in the hall which is between the kitchen and lounge. We can hear it if there is ever a fire in all rooms, and the rooms upstairs.
True, The general rule is,
Kitchens and garages, Heat alarms,
Landings, Ionisation smoke alarms or combined optical smoke and heat alarms,
Bedrooms, Living rooms and hallway, optical smoke alarms or combined optical smoke and heat alarms.