Yeah, I thought this article was going to be about robocalls. I don't think I'm alone in realizing that for now most robocalls auto-disconnect if they don't hear anything on the line for somewhere between 15 seconds to a minute depending on the software's patience I suppose. This has taught me to never answer the phone for an unknown number and immediately say something, just to put it on speakerphone and let it pick up ambient fan noise or whatever for a minute-ish. If it is a robocall and it auto-hangs up, I win.
If it is an actual person calling it is an awkward etiquette dance for a minute or so while people wait for that polite "Hello?" that the receiver is supposed to kick off the conversation with. I don't know if the etiquette needs to shift in a time of robo-callers or what. I appreciate that there's an increasing air of excuse now of "fiddling with my phone equipment because calls are so rare" that this article addresses (though the article believes this to be a bad thing).
You may be over-doing it. Most robo-calls wait for a second "hello?". So you can say it once, then wait a bit for a human to answer normally. Then if they don't, you just hang up, as the computer is waiting for that 2nd "hello?".
That is something I often rely on ambient noise to do. My work keyboard is quite loud. My home a/c makes a ton of white noise and the occasional thump when it clicks off. It also currently makes a lot of loud water sounds when it is off. I use throat clearing and coughs sometimes, too.
It's a silly game to play with these robocalls what they are/are not listening for and it seems to change from time to time (and obviously from bot to bot). "Dead silence" is sometimes easiest and the easiest way to describe it (though I believe I did mention I generally put things on speaker and rely on ambient noise), but yes, not "required" and it is a dumb space to explore sometimes.
If it is an actual person calling it is an awkward etiquette dance for a minute or so while people wait for that polite "Hello?" that the receiver is supposed to kick off the conversation with. I don't know if the etiquette needs to shift in a time of robo-callers or what. I appreciate that there's an increasing air of excuse now of "fiddling with my phone equipment because calls are so rare" that this article addresses (though the article believes this to be a bad thing).