Do some of the sound effects that I hear in this game were taken straight from the DS Zelda games? Seriously, there were a few instances where I heard something and went, "Hey, I heard that somewhere before". Take a piece of furniture with a flame for example. When you blow it out, it sounds just like blowing out the torches from Zelda. And certain footsteps on the sand and snow sound familiar too. The sound of the wheel of the hamster cage? Sounds just like those wind vanes from Zelda too. Don't believe me? Well, if you have Phantom Hourglass and/or Spirit Tracks, do those things that I just mentioned and you'll hear the similarities between the two.
I wouldn't be surprised if they used some sounds from other games. After all, if you already own the rights to an existing sound effect, it's way easier to use that instead of putting in the time and money to create a completely new sound effect. Most people wouldn't even notice it, and those that do would just think of it as an interesting little trivia fact. It's also a thing Nintendo themselves have done in the past.
I haven't looked into the sound design for New Leaf, so I don't know what it reuses specifically. Just that Nintendo has been known to reuse assets in the past.
