Any time you're planning to make noise in your yard in the evening it's good policy to let your neighbors know beforehand, or risk the chance of having a noise complaint filed against you. The easiest solution? Usually an invitation to your event is enough to pacify even the most sensitive ear in your neighborhood, but even if your neighbors aren't the type to complain, don't dismiss noise issues. Under the rules of the Municipal Research and Services Center of Washington, for example, audio devices -- that includes your DVD player, speakers and any other gear in your movie-playing setup -- are considered a noise nuisance depending on the time of day you're using them, and if your movie is easily heard beyond 50 feet (15.2 meters) of the property boundary of your yard after 11 p.m., you could be cited [source: MRSC]. Check with your local municipality to find out if there's a similar ordinance.
To help reduce noise, consider adding a solid, as-tall-as-possible fence around your property, especially if you plan to have regular backyard movie nights.