Increasing Effectiveness of Train Horns Without Increasing Intensity

This study assessed methods of increasing the effectiveness of train horns without increasing intensity. Special attention was paid to the problem of masking by car noise. In Experiment 1, the audibility of pure tones presented in car noise was assessed across a broad range of frequencies. In Experiment 2, the urgency of pure tones presented in car noise was assessed across a broad range of frequencies. In Experiment 3, urgency of novel train horns was assessed in quiet. Novel train horns varied with regard to spectral centroid and musical dissonance but not intensity. Findings suggested that train horns could be made more effective by ensuring substantial mid-frequency energy, shifting the spectral centroid higher, and increasing musical dissonance.