How do you deal with he said she said tenants drama?

[Jorge Garifuna]

The tenant downstairs complains that the tenant upstairs makes annoying noises sometimes in the middle of the night. 

When I approach the tenant upstairs about the issue, she says that she only does it to send the signal to the tenants downstairs to keep their noise level down. 

Both tenants pay on time and I've talked to both about the issue, but it keeps happening repeately for about two weeks now. 

I've been very good at addressing my tenants' issues, but this one seems to be one of those that I'm not sure about what to do anymore, since I already talked to both of them. 

Any ideas on how to deal with situations like this?

[Anthony R.]

Haha I had the IDENTICAL issue with two females last Aug. After trying to play the middle man for about a month I realized they were both being a pain in my ***. 

I told them that I am not their mommy or daddy. They are middle aged women and can handle this on their own. Unless I get a police report for a noise complaint no one was in violation of their lease and there was nothing I was going to do. 

I finished by telling them that if I got one more complaint from either of them about this and it wasn't legitimate that I was going to blindly deny renewing both of their leases when it came to pass.

I haven't heard from either of them about this since. (They also both renewed)