Source Danny Choo:
For some reason or another, some ladies in Japan are rather shy when it comes to jettisoning human waste.
For this reason, bathroom appliance maker TOTO invented the Otohime [音姫] which literally means "princess of sound."
Otohime is a device that emits the sound of water to disguise the real sound of the trickle of pee or the kerplonk of 1 kg of poo hitting the waters surface. [edoh: I ROFL'd xD] The video below is an example of the device in action.
credits to norakuro3