This is the 'Noise Decorator' developed jointly by Japanese houseware manufacturer LIXIL and electronics company Roland. The $300 device automatically detects when you're going to the bathroom and masks the sounds with other sounds. There's also a $200 version that you have to start and stop manually with the wave of a hand. So...$100 extra for a motion detector? I'll just sing at the top of my lungs for free. The product description, via Google translation:
"Sound decorator" jointly developed by LIXIL and Roland now has a sound source that demonstrates "masking effect" that analyzes the frequency band of the sound when using the toilet finely and makes it difficult to hear the sound when using the toilet It is an acoustic device for toilet. You can get a sense of security with thoroughly sticking "sound", and you can taste relaxation with the sound that makes the image of the forest such as Ogawa's birthplace and wild bird chirping. In addition, it prevents unnecessary flushing for the purpose of protecting the privacy of the toilet user, leading to significant water saving.
Admittedly, it does suck listening to other people go to the bathroom. That's why everybody should just play Youtube music videos on their phones as loud as possible. It's the respectful thing to do. "So that was you blaring Harry Styles' 'Sign Of The Times' earlier?" Yes. "Well you were in the custodial closet." Whatever, so I pooped in a mop bucket, it was early and I hadn't had my coffee yet, you're not perfect either.
Keep going for a video demonstration.
Thanks to Dave B, who agrees airport bathrooms are the worst. It's like they purposefully made the acoustics sound like an echo chamber. I heard a fart bounce around the room for almost a full minute once.