Abstract:For the quantitative analysis of the speech articulation in highspeed train compartment under strong noise environment, the speech articulation was achieved in different positions of highspeed train compartments under different speeds and speech levels by using the relationship between Chinese speech articulation and the speech transmission index (STI) according to IEC 6026816(2011). The results show that the interior location below the pantograph is the weakest position for speech articulation. In addition, at this position speech articulation changes with speed linearly rule and with speech level quadratic nonlinearly. Then, by using multivariate nonlinear regression analysis, the relational expression of interior speech articulation, speed and speech level was established. The standard deviation between the test results and the curve was 1.75% and the coefficient of determination R2 was 0.963, which indicates that the expression can well simulate the relationship among them. Compared with the evaluation method based on speech transmission index, the objective parameter of this evaluation method is simpler and this method has more application values.