If spokes are loose enough for you to hear them, they're loose enough to send the wheel way out of true. You'd notice that under braking even if you weren't looking for it. Next time you're in there, spin the wheel, check that it's reasonably true, touch the spokes to be sure none of them are grossly loose.
I can't quite figure what kind of sound you're talking about, but if they had the wheel reflectors on (in the USA they're legally required to sell them with them on), there's a good chance those might be noisy.
"I felt [the women's Olympic marathon] was as important as women having the right to vote, because talent, strength, and capability cannot be fully realized if there are no personal rights to allow them to be visible or be deemed significant in the first place." - Kathrine Switzer, Marathon Woman