If you're getting your phonemes from an IPA dictionary, couldn't you check for emphasis too?

Seems like you'd want to match words that begin and end in weak syllables, e.g. Beethoven + veneer = Beethoveneer (overwrought, superficially emotional music).

You can also pair strong syllables: sorbet + Bayes = Sorbayes (dessert ordered on the condition that real ice cream is unavailable).

But putting a weak last with a strong first wrong-foots you: Beethovunforgiven.

EDIT: in case it sounds like I'm nitpicking, I love this.