The uniform asymptotic solution derived by R. G. Kouyoumjian and P. H. Pathak for spherical sound diffraction by a wedge of an arbitrary angle, and the two asymptotic solutions derived by A. D. Pierce, are quantitatively compared with the rigorous integral solution developed by A. Wiegrefe, H. M. Macdonald, and H. S. Carslaw. Level difference between Kouyoumjian & Pathak's asymptotic solution, and the rigorous solution, is less than 0. 5 dB for a wedge of arbitrary exterior angle upsilon pi only under certain conditions involving the distances from the edge of the wedge to the source and the receiver, and the shortest distance to the receiver from the source in stepping over the edge; a ratio describing the condition is given in the paper approximation error of Pierce's first and second asymptotic solutions became greater as upsilon approaches 1. However Pierce's second solution has less approximation error than Kouyoumjian and Pathak's solution for upsilon greater than or equal to 1. 4. For upsilon equal to 2, namely a half plane, the three asymptotic solutions become the same expression. These results were confirmed by experimentation.