integer o = -1;
string SOUND = "9fb1f482-5edf-1544-98c4-b8f86ea9ea26";

 
default {
    changed(integer change) {
        if (change & (CHANGED_REGION_START | CHANGED_REGION)) {     
            llResetScript();
        }
    }
 
    touch_start(integer total_number)
    {
        if(o = ~o) {
            llStopSound();
            return;
        }
        llLoopSound(SOUND, 1.0);
    }
}