What are you supposed to do when you hear someone scream outside?

I'm sitting hear in my apartment with the windows open and I hear someone scream, maybe two or three times. It could be a woman or a child. It doesn't sound specifically like distress, although it doesn't sound specifically playful either. I scream in more distress when I encounter an ordinary household pest. I can't see anything really, but it's dark out. The scream could be coming from the street, or the balconies of any of the neighbouring apartment buildings, or inside any of the neighbouring apartments if someone has a window open. The source of the scream could be anywhere within a three-block radius containing well over a thousand households. That's if I'm estimating correctly how far sound can carry.

Now I'm hearing other screams that sound playful from the same general direction. They are a mix of different voices, some male, some female, some children.

Now, if someone is in fact being attacked, it will be all over the newspaper tomorrow that no one called for help. But I'm sitting here 12 storeys above the ground, unable to see anything. Am I supposed to call the police saying it's possible someone in my general vicinity in this high-density neighbourhood might possibly be in distress, although it's possible they might be having fun, or might be a child being tormented by their sibling, or might be having an overzealous game of hungry hungry hippos?

Now I heard two more, more like the original voice, that sound more towards the distress side of the scale (but not objectively distressful).

It's 11:00 on a Friday night in a neighbourhood with a young adult demographic, so it would be very odd indeed if there was no one having fun under the influence of anything within this radius. And people having fun under the influence do often scream while walking down the street, although they tend to sound more obviously playful.

Two more: one not-really-playful, one more playful, followed by a loud collection of various voices talking loudly. Whatever's going on, there's an assortment of people of various ages and genders there, assuming I'm hearing who's all in the same place properly.

If I had a bug, I would scream in distress several times. Then I would deal with it, drink or med myself down, and go to sleep. If someone who isn't on my floor tried to come to my rescue, they'd never find the source of the screams.

One more, again didn't seem distressed or non-distressed, but the number and variety seem odd. Then two more that sounded like a child being tormented by a sibling, and a short one that sounded playful. A dog barks, a child shouts, a man calls out in response.

I don't want to live in a neighbourhood where you scream for help and no one helps, but I don't know where this person is or if they are screaming for help. Either they aren't or I have convinced myself they aren't. What are you actually supposed to do in this situation? What can I do if I'm ever on the street screaming for help to maximize the chance someone will help me? (One idea I once came up with is, if at all possible, to run out into traffic. Then I'm suddenly all the cars' problem too.)

And now it has started raining, and all I can hear is the rain beating down on my metal balcony railings.