The audio begins with a low distant hum, indicating the approach of a high-speed train. This hum gradually increases in volume, setting a sense of anticipation. As the Thalys, a renowned high-speed train, approaches closer, the hum transforms into a powerful roar embodying the sheer speed of 300 km/h, creating a sense of awe and admiration. The sound is immersive, making listeners feel as if they are standing right beside the tracks. Suddenly, there's a rush of noise, a sonic boom, as the train passes by. This is the Doppler effect in action, showcasing the change in frequency of a wave in relation to an observer moving relative to the wave source. The train's rapid transit creates a gust of wind, which is audible as a whooshing sound following the train's passing. The audio fades out as the train's sound recedes into the distance, leaving behind a breathless silence. It's a thrilling sonic journey that encapsulates the marvel of modern