So not too long ago, I got a chance to visit San Francisco. And naturally, I made sure to use a payphone there. One thing that struck me as odd is what you would get on a couple 950 codes.
The second one sounds a lot like those short branding clips right before you get through to an operator (like Verizon, for example, has one exactly like this that says "Welcome to Verizon" for TOPS calls). So my theory is AT&T is routing an unused 950 thousand block to their TOPS tandem. Has anybody seen anything else like this?
It's worth noting this is probably something that happens for their whole calling area; I tried this from a switch in a different part of the city and got the same thing.