Place it on the landing at the end of a descent sequence, after Scream Meme Sound has covered the fall itself, then close with Emotional Damage Meme Sound once the character realises where they have ended up.
About this sound
This is a short sung greeting, under three seconds, delivered in a bright voice over a quick musical rise. It feels cheerful and slightly absurd, like a grand hello for a place that is anything but welcoming. It comes from a fan musical take on Undertale, the 2015 game set in a cavern world below the surface, where the line opens the show for a newcomer who has fallen in.