Call-and-response attention getters are great in elementary school. In a room full of eighth graders, "Class, class!" gets you an eye roll and a sarcastic "Yes, yes."
Older students still need a signal. It just has to be simple, calm, and the same every time.
Pick one signal and protect it
A few that work with teens:
3-2-1-done: count down out loud, and by "done" every voice is off and eyes are up.
Hand up: you raise a hand, students raise theirs and stop talking.
Stand still: walk to the same spot in the room, every time, and wait.
Lights or a chime: good for loud group work when voices won't carry.
The best signal is the one you'll use without thinking. Don't rotate through five of them.
Teach it like content
Practice it the first week. Seriously. Have students talk, give the signal, and time how long it takes to get silent. Write the time on the board. Try to beat it. It feels silly, and it works.
Expect it to take weeks
The first time I used a countdown, it took about six weeks before it worked every time. Students test whether you mean it. Every time you give the signal and then start talking before the room is quiet, you teach them it's optional.
Never talk over the noise
This is the whole trick. Wait for full silence before you speak, even if it takes 20 awkward seconds. If you talk over the last few voices, the signal stops meaning anything.
Free tools
Classroom Attention Getters: The 3-2-1-Done Method on Elevate the Norm tells the full story of making it stick.
Classroom Management Strategies for a Talkative Class helps when the noise is the main issue.
Classroom Management Strategies That Actually Work in Grades 6–12 is the big-picture guide.
Want it ready to print
Everything above is free. If you'd rather skip the prep, my TPT store, Teacher Emergency Toolkit, has print-ready packs for grades 6–12, including a free resources shelf and teacher forms and templates.
Need a warm-up for tomorrow? A new set of free bell ringers goes up every morning at Daily Bell Ringers.