My mommy and daddy don't know the difference between alkaline and various chemistry rechargeable batteries, even though it's been a persistent issue since when THEY were kids!
That's a cute lion! I like these toys, I might have a dozen Dogs that do different things, like two versions of Scamps, an interactive pup, talking Wishbone, Roll Over Rover and several singing Dogs.
Most of those with voices don't slow down, they just get scratchy sounding with low batteries.