It's not until after she dies that Scout and Jem get a sense of what's going on behind the drool and venom: Mrs. Dubose is a morphine addict who had vowed to go clean before she died, and enlisted Jem and Scout (without their knowledge) to keep her off the stuff for longer and longer periods of time.
http://lungsounds.net/rales-lung-sounds/ - Rales lung sounds are small rattling noises heard around the lung. This happens when air exposes closed air spaces. Rales can be shown as wet, dry and coarse.
Breath sounds can be either normal or abnormal. These sounds come from the lungs when you breathe in or out. These sounds can be heard using a stethoscope or simply when breathing. Abnormal breath sounds can indicate a lung problem, such as: an obstruction.