And here's our second floor:

One of the first floor bedrooms is under the second floor dining room and the path to the living room: a pretty high traffic area! Add to this that the person living in that bedroom works from home during the day, and our kids are also home during the day, and we have a noise problem.

Some aspects of this problem are temporary: (a) this current tenant works from home, but we might have future tenants that don't and (b) our kids are currently home during the day but in a year and a half Lily starts kindergarten, and at that point I suspect we'll move Anna to some sort of daycare. On the other hand, there'd still be kids running around some in the afternoons, evenings, and weekends. Plus the foot traffic of adults, which while less enthusiastic involves more weight.

The current ceiling, I think, is:

This is pretty typical for a house around here, but it's not great from a sound transmission perspective. We tried putting down half inch foam on our floor above, but that didn't noticeably help.

I'm trying to figure out if it might make sense to do something with the ceiling below. A contractor who does acoustic ceilings suggested removing the existing ceiling and puting in something that is both heavy (two layers of 5/8" drywall) and acoustically isolated (mounted on springs). They wanted $10k if they did the whole thing, or $5.5k if we did the demo and drywall ourselves.

Another contractor, one who installs suspended grid ceilings, suggested we leave the ceiling alone and install a drop ceiling underneath it. This would be a lot cheaper, about $1.1k, but probably wouldn't work as well. I talked to them about noise reduction, and they said that when they did a job for a restaurant under a dance studio they installed seismic clips, which lose you about a foot of ceiling height but reduce vibration. They said they could do that for $1.4k. There's plenty of height to work with (9ft) but the downsides are that (a) it's kind of ugly [1] and (b) we still don't know how much it would block sound.

Our tenant is currently traveling for a while, so now is the ideal time to do this work if we're going to do it. Does anyone else have experience with this? I'm not sure what makes sense.

Update 2018-04-29: it's done.

[1] It looks like there are some options with nicer tiles than the standard office-style I'm used to seeing? Maybe those would look decent? I'm also not sure how much the attractiveness of the bedroom ceiling matters.