A block you can get from the villager maybe the noteblock. You can use it and it will broadcast a sound to just your teammates as a warning. Idk how many times I've seen someone that i can't get to just walk naked into the base past everyone else and punch the bed.
I like the concept, but some players don't use sound. If we were going to implement this, I don't see why they wouldn't implement a better way to signal your team through chat or something. No support, but cool idea.
Yeah i usually do try to communicate with chat but a lot of ppl are busy gearing up or w/e and dont see the warning. I don't always look at chat myself. I didn't know it was "a thing" to play without sound. Seems weird to me.
Support. This would be good if it said something in chat, only to your whole team, like "_____ is in trouble!" or whatever the concept is.
I like RebornWolf's idea. U could place a block near the bed or on a bridge and if an enemy got within, say, 5 blocks of it, the alarm would sound and/or chat notification Maybe it would cost 6 gold? Anyway, it seems like the majority of people are against the idea so I guess not.