Ear plugs can be purchased at any pharmacy. Kids can be carried away by sights that are mere fiction for adults. Therefore, it is important to prepare your youngster for any potentially frightening or perhaps simply fanciful sights that they might see. The sudden appearances of Monstro in Pinocchio and the the witch in the Snow White attraction is a common concern. A child can potentially see that image as a real whale or witch, so let your kids that they're about to see a pretend witch.
Nothing can help make someone over come a phobia like being aware of the realities surrounding it.
One last aside, don't forget to warn your kids about any characters that might be at a breakfast or dinner event or that they might come across in the parks. A great example would be to avoid the horse-drawn streetcars if your child has severe allergies. If Johnny just threw up on Space Mountain, you might want to give him some time before making him walk by the bakery or candy shop. Smaller children can be easily intimidated by crowds. This is especially true if you and your child are separated by the flowing masses.