True cars and trains are loud. However, we're on the verge of both Caltrain and car electrification, which will significantly reduce ambient noise.

I can't believe we haven't cut & covered the Caltrain line yet. I imagine that's a project even the plentiful peninsula NIMBYs could get behind.

As sibling points out, airplanes at moffett are rather far away, whereas these flying bikes are meant to be point-to-point in dense environments. Also note that there's lots of regs & techs that help reduce noise for larger planes, and I'm not sure the same is going to be true for these smaller vehicles, similar to how all those two-stroke lawnmower and leaf blower engines are horrible both environmentally and noise-wise because they're optimized for size.

At normal highway speeds most car noise comes from air movement and tires. Electrification will only deliver a slight noise reduction.

Airplanes are a few orders of magnitude farther away than what these vehicles are suggested to fly at.

The Caltrain horns are so loud I have decided I believe in a conspiracy theory - the volume was mandated in the name of "safety" by a lobbying group secretly working for the auto industry.

Nowhere else I've been are trains so obnoxiously loud.