footsteps sound conflict with Plasma in 3ds max

I'm working with the footsteps sounds in my Age, (with 3ds Max7) but there is something strange happening: they all work with a beautiful effect, except for one particular area where instead of hearing the sound of steps on the stone I hear the sound of the avatar swimming in the water. This swimming sound is applied on a distant plane not linked in any way with the stone sensor area. The water area surrounds the stone area. The strange thing is that I have other footsteps sound areas placed in the same setting (surrounded with a ring of water) but they don't have this kind of problem.
Can anyone help me?

Can anyone help me?




