Given that it started at a "point", it would go outwards in a circle, so you would end up with a "line" where sound from each direction crossed over. In theory,

Given that it started at a "point", it would go outwards in a circle, so you would end up with a "line" where sound from each direction crossed over. In theory, you could end up with a point where they all met again, however due to the focusing effects of the various landscape, and ambient pressure differences, this would rather be a diffuse area than a concentrated point, just like the lines where the sound met wouldn't be straight either. This, combined with that the fact that on the on the "other" side of the world it was really only detectable by barometric readings means that you would be hard pressed to notice it, even along those lines and or point.