In theory, predicting community noise levels is relatively easy --- once the needed information can be found. While the equations needed to formulate a noise prediction model are in the literature, unfortunately, they are spread between many references. Adequate information on noise levels of sources --- either as sound-pressure or power levels --- is often not available in the literature. Further, transmission loss data at low frequencies are not usually available. When one gets around these problems, another set of problems arises that is related to the accuracy of the models developed. These problems include source size and directivity, barrier and screening effects of equipment, reflections by equipment and buildings, piping and minor equipment, atmospheric and ground effects, and effectiveness of noise control barriers. Typical prediction technology is summarized. Problem areas that affect accuracy of noise predictions are identified and discussed.