static int f=0;
...
if(visible >= 0) {
mySetLight();
glEnable(GL_LIGHTING);
mySetMaterial();
glutSolidTeapot(30.0);
glDisable(GL_LIGHTING);
PlaySound(NULL,NULL,SND_PURGE);
f=0
} else {
glColor3f(0.0, 0.0, 1.0);
glutWireTeapot(20.0);
if(!f){
PlaySound("se_sad02.wav",NULL,SND_FILENAME | SND_LOOP | SND_ASYNC);
f=1;
}
}