I used to get ~6-10 spam calls per day and I would do what you describe: ignore the call. Then I started picking up, immediately muting myself, and waiting. The

I used to get ~6-10 spam calls per day and I would do what you describe: ignore the call. Then I started picking up, immediately muting myself, and waiting. The auto-dialer gives up after exactly 10 seconds of silence and hangs up. This has reduced my spam calls to 1-3 per WEEK. The downside is sometimes real people call (like a contractor your landlord hired), hear silence, and don't say anything themselves because they're waiting for a "hello?". Whereas ignoring the call would let them actually leave a voicemail which would be useful. As I learned recently: sometimes real people don't call back a 2nd time.