A theory of vortex sound formulated in the form of multipole expansions is applied to the oblique collisions of two vortex rings with various angles. Using the theoretical formula, the coefficients of the multiple modes of the far-field wave pressure are estimated by the numarical data of computer simulation. Time evolution of the vorticity field is obtained by solving a viscous imcompressible vorticity equation with a vorticity-potential method. Numerical simulations are carried out for 23 different collisions of two vortex rings with the same core and ring parameters but the different initial angles θ between the axis of rings(0° ?? θ ?? 66°). The results show that the far-field acoustic pressure is strongly related to the stretching phenomena of vortex tubes.