5. The correct answer is frog. Since a frog doesn't have the most eloquent voice (think of its harsh ribbet sound), and Carnegie Hall is one of the most renowned places for music, this statement means that the voice does not sound very good.
6. The correct answer is milk. This statement most likely means that there's a lot of noise, like splashing and sloshing. Crows can't swim, and milk is thicker than water, so it's easy to imagine a crow thrashing around in milk.
7. The correct answer is in ankle bracelets. Someone walking in ankle bracelets is going to be making a harsh, clinking noise, weighed down by the weight of these bracelets. If the author compares the voice to this, then the voice is (again) making a not so nice sound.