I had two silent, barring some office appliance noises, voicemails just today.

The number was on a spam list, but somehow managed to leave a "message".

The most surprising thing is that it was obviously a person calling and not a bot, as I was hearing the rustle of something (mouse?) being moved over a desk.

I normally don't answer calls I don't recognize the number to, but if I might be expecting a call and have an inkling it might even possibly be spam, I just answer with a short 'ya?'

Slightly rude, but saying nothing at all is just bizarre to me.

Edit to add: One thing I've done for the last decade or so is use a number from an area code I don't live in. Most of my spam calls come from the same area code, so if I see that I know it's spam or a wrong number.

I clear my throat. Do it loud enough that the other end can tell someone is on the line, so they'll know to start the conversation. It isn't a rude "WHAT" type answer, but it doesn't directly acknowledge the caller, and is not inviting a conversation. Its a common enough act that it's not suspicious nor weird to hear during a conversation, and therefore its not off-putting if extended family or clients called from an unknown number.

It doesn't share my voice (for fingerprinting, demographic leak, etc, smh).

Also works as a bot filter - Humans tend to start with a "hello..?" because they're not sure anyone is there, while robots use the non-zero audio as a signal to start talking with full confidence.

Answer it as if somebody had knocked on your front door: "who is it?"

> mentally accepting whoever is on the other side (like hello tends to do)

I don’t get that. How is answering the phone mentally accepting the caller? What does it even mean to mentally accept? Is it that you don’t want to talk? Then let it go to voicemail and decide if you want to call back or not? I think I’m missing the point.