All you need. Nothing you don't.
If you are praising God with your spirit, how can one who finds himself among those who do not
understand say “Amen” to your thanksgiving, since he does not know what you are saying? 1 Corinthians 14:16
“Amening” is an aspect of interactive meetings which usually gets overlooked but it is a meaningful addition to any Christian meeting.
It affirms both the speaker and hearer and obviously it’s a God-ordained element of worship.