Train horns produce a deep, low tone and are generally louder than air horns. In contrast, air horns have a higher pitch and may not be as loud as train horns. However, some air horns can be louder than certain train horns, so personal preference plays a role in choosing the best option.

The primary difference between a train horn and a standard air horn (like those on a truck) lies in their power, acoustic complexity, and legal regulation. An air horn typically uses a single trumpet to produce a loud, monotone blast to get attention in traffic. A train horn, however, is a sophisticated musical instrument known as a "Chime Horn," consisting of three to five separate trumpets (bells) tuned to a specific musical chord (like a major sixth). This chord is designed to be heard over massive distances and to be "unmistakable" even in loud industrial areas. Train horns operate at significantly higher air pressures (up to 140 psi) and produce sound levels between 110 and 143 decibels, which is loud enough to be heard miles away. By law, train horns must follow specific "sequencing" (like two longs, a short, and a long) when approaching crossings. While both use compressed air to vibrate a diaphragm, the train horn is a specialized piece of safety equipment engineered to dominate the acoustic environment for miles.