One of the things that makes a low-flow toilet work, sort of, is high pressure: mere gravity can’t do it alone. The price you pay for saving water, apart from the cost of the new throne, could be a much higher noise level:
[Acoustical consultant Noral] Stewart was hired to solve a knotty office problem: overly loud flushing sounds from new low-flow toilets that were carrying over into seven rows of five offices (each row on a different floor), in which the three middle offices were right next to the rest rooms. You really didn’t want to be the poor sods who got the middle offices on each of the floors: those shared a wall with both the men’s and women’s restrooms. Talk about Flush Central. Preliminary measurements of the sound levels showed many of the flushes were louder than 60 decibels (especially in that middle office), and almost all topped 50 decibels. That’s roughly the same level as a typical conversation, which might not seem all that loud, until you realize that every time someone flushes a toilet, those in conversation would be momentarily drowned out by the sound. Noise from ventilation systems, for comparison, is usually around 35 to 45 decibels. (Inside the restroom, sound levels are more like 80 decibels; the loudest Stewart measured was 96 decibels in one of the women’s stalls, a good 20 decibels higher than your average toilet’s flush should be.)
Ninety-six decibels, incidentally, is the California legal maximum for off-road motor vehicles. This is not a sound level you want coming from directly behind you. And it took several layers of different types of sound insulation to keep the noise from making its way into office space.
Suddenly I’m feeling better about my Incredibly Wasteful old-style bowl.