For public safety, freight and passenger trains are required to have audible warning devices to signal the approach of trains at grade crossings, and in case of an emergency, where there is a shared right-of-way or other possible public access to railroad tracks. Some communities have expressed a desire to reduce the need for sounding warning horns at grade crossings. Although very expensive, grade-separated railroad crossings are one means by which communities and railroads can reduce the need for horn blowing in populated areas. Efforts are being made to develop new grade crossing safety devices that reduce the need for horn blowing. However, use of warning devices such as horns or whistles to signal the approach of trains, especially at grade crossings, will probably remain a major source of railroad noise in most communities through which railroads pass. A noise prediction model is presented and compared with noise data measured for freight train locomotive horns at grade crossings. Horn sounding duration is included in the model, and its effect on time-weighted community noise descriptors such as L[inf dn] is examined.