On two occasions, I have had an odd sound alert without visible explanation.
The sound is three tones - two of one pitch with a slightly higher one between - sort of “dong ding dong” - repeating until the phone is unlocked.
On both occasions my phone was plugged into my car. Android Auto functions continued normally.
What does this sound actually mean?
Sounds like the “Cesium” default alarm tone. Did you happen to set it as a notification sound? Is a timer going off? An alarm? I’d suggest checking the clock app, to make sure there’s no unwanted alarms or timers set. Or check your sound settings, see which type of tone is set to Cesium.
Hmm… it is Cesium, but I’m not using that. I use Rooster Alarm for my default alarm sound.
This has happened on two disjoint occasions - There was the running remnant of an earlier (way so!) alarm and this struck at the time of a cancelled alarm, this time… but it is very odd.
I don’t know if this is related, but I’ve recently found that Cesium had suddenly become the default alarm tone on all my alarms.
I intentionally didn’t use Cesium cause I hate it and it makes me so irrationally cranky to wake up to, and it honestly took me a week or more of cranky mornings before I even realised what was happening.
Anyway, since it’s a month ago you’ve probably figured it out, but I suspect whatever update changed it had something to do with it. The accursed Cesium update.