The Real Reason Dead Bodies Sometimes Make Noise
By RICHARD MILNER
History - Science
Corpses can produce sounds because of the same elements that produce sound anywhere else — shifting air and gas. If there's any gas left in a body after death, it will make noise.
Dr. Mary Lachman told The Healthy that air might pass through the vocal cords and sound like groaning or moaning, while gasses in the body might squeak, peep, or squeal.
Health and wellness expert Caleb Backe explained to Bustle that emergency care workers often pump air into the lungs and stomach when attempting to revive someone.
If an emergency care worker performs CPR on a patient and that patient passes away during CPR, the weight of chest compressions pushes air out of the lungs and the stomach.
Even if this chain of events doesn't happen, a body will exude air if it's moved, which will be at some point after death. Backe says that this scenario is "extremely common."
Gastroenterologist Purna Kashyap told NPR that bodily bacteria produce gas. McGill University said bacteria "roam around and digest our tissues" after death, producing more gas.
If a person’s slide to death is slow, HPC Consultation Services says that person may experience apneic breathing — a diminished frequency of breaths.
The space between breaths may grow longer and longer until finally, the person takes their last breath. This final exhalation will be the very first noise a person makes when dead.