Step into any public restroom stall in Japan and you’re likely to be enveloped in a soundscape. No, not that kind. It’s the babble of running water, perhaps peppered with cheerful tweets and birdsong, ...

Japan's famously high-tech toilets are getting a new upgrade: sound-masking devices designed to cover up the less melodic realities of public restrooms. These gadgets, often called Otohime, or "Sound ...