Abstract: The characteristics of noise distribution at the ends of the high-speed coach are studied by the means of field measurements. The interior and exterior vibration analysis and the interior cavity acoustic modal simulation are conducted to examine the characteristics of the noise distribution and figure out its mechanism. Counter measures against this kind of interior noise are proposed at the end. The measurements show that the sound pressure level at the seat by the windows is 8 dB(A) higher than that by the aisle, although the horizontal distance between the two seats is only 1.2-1.7 m. The interior noise, the interior and exterior vibration accelerations all have a peak frequency at 111 Hz. This vibration frequency matches the passing frequency of sleeper span at the operation speed of 250 km/h. And the acoustic modal analysis show that sound pressures are almost high on the sides and low in the middle at the cross section at 111 Hz. It is found that the interaction between the structural vibrations of the car body and the interior cavity sound pressure is the reason for this special noise distribution at the ends of the coach. This work provides a theoretical basis for counter measures against the interior noise problems in high-speed trains.

Key words: high-speed train;interior noise;ends;noise distribution;acoustic modal;standing wave