Place it near the end of a reveal, after the big reaction has landed, so it answers the excitement and closes the moment. Put Oh My God Wow just before it for the surprise, then follow with No No Wait Wait if the conversation turns back to disbelief.
About this sound
This is a short spoken reaction clip, lasting about four and a half seconds, in which a voice delivers the line 'I've heard of that' in a calm, knowing tone. It feels dry and slightly smug, like a quiet nod to something familiar rather than a big laugh. The delivery lands as a deadpan acknowledgment, useful when a claim needs no extra excitement or surprise.