Depends on where the midship location is. Part of it is under the chairs and lounges that are located pool-side, in which case you might hear those being moved around while they clean. Part of it is under the fitness center (port side). We sailed last week and the fitness area was only open from 6 AM - 11 PM. My DH asked why, and they said it was from noise complaints otherwise -- I'd assume from the cabins below. On the other side, you've got a section with the library, card room, and further front, the spa. I can't imagine those would be noisy at all, but I'm not sure exactly where the suites are located.
If it was me, I'd go for a starboard one, closer to the front, and you should be fine. By the way, we walked down that hallway to get to the bridge viewing area and didn't notice any noise at all from midship forward, but it might be different in the actual cabins.