Researchers at the Brigham Young University (BYU), Utah have invented a way to buffer out the sound of the airplane toilet flush. Waking up on a plane to a loud, slurping sound of the toilet is a common experience.
Airplane toilets are vacuum toilets. When you flush in an airplane toilet, the vacuum swirls all the contents from the toilet bowl and deposits it in a septic tank, and the blue liquid sanitizes the toilet bowl for the next user.
The research team at BYU have added an additional piping between the commode and the flush valve. This change in the placing of the pipe seems to have made the biggest impact. It has reduced the sound to 16 decibels, making the run to the toilet on the plane a much private and quieter affair.
Airplane toilets are more environmental-friendly as compared to the normal toilets. For one, they use very little water. Vacuum toilets flush with half a gallon or less of water (2 liters). They also use smaller diameters of sewer pipes.