If men are coming and going and this worries you too, I'd stroll outside and look at license plates and write them down in your log that is keeping track of the screams. I would be discrete about it so as not to arouse suspicions.

Do you know her full name? Does she go to work every day?
How old is she? Family? living alone?

I'd try and Google her, and also check the free public records for your state and county. It is amazing what a person can find out these days!

For a small fee you can even find out if she has a criminal record.

Since it has been 2 months already, a welcome wagon approach would be awkward.

I for one don't think your neighbor has a medical reason like Tourette's. I just get a feeling about this at this point.

But keeping yourself busy with the log and documentation is one way to keep yourself less anxious about it all... acting is always better than reacting.