In some segments of Christianity, shouting “Amen!” is encouraged, and at times even requested with a phrase like “Can I hear an 'Amen'?”
This isn't a Biblical way of using the word. But even if it were, it would still be problematic. It is asking for immediate assent to what is said, based on enthusiasm or assumptions, rather than on careful reflection and investigation.
I was struck recently by the contrast between this sort of 'Amen' and the exclamation 'Aha!'
'Aha' reflects a discovery, an understanding, usually coming after a significant process of investigation and pondering.
I think we need to cultivate a Christianity that puts less emphasis on amens, and more on ahas.