It's usually the males that bray more than the females; they can be quite vocal...music to a donkey lover's ears (once you know the animals, you can tell who's braying and even why!). Very intelligent animals, easy to train, requirements similar to a horse (vaccinations, deworming, hoof trims, shelter) but usually don't require grain, just pasture and hay.
I see you have been bitten by the donkey bug. I really love mine, especially when they foal. The miniature foals are so small and so cute! My herdsire has this big basso-profundo bray. I have never heard anything else like it. Sounds nothing like any donkey bray I have ever heard.
They are smart and can be trained. Mine are like big grass eating dogs. My herdsire is about 30 inches at the withers.