Train horns are loud, powerful devices used on trains to signal their presence and warn people of their approach. They produce a distinctive sound that can be heard from a distance, helping to prevent accidents at crossings and in populated areas. The horns are typically activated by the train crew and can vary in pitch and tone depending on the type of train and its purpose. The sound of a train horn is regulated by laws in many countries, including the United States, where specific decibel levels and patterns are required. Train horns are an essential safety feature, ensuring that pedestrians and vehicles are alerted to the train's movement, especially in areas where tracks intersect with roads.