It can't be just that, try this. Tap '1' 2 times, then tap '2' a few times, it's worse! :)
Global laserfire1:TSound = LoadSound("data\laserfire1.ogg") Graphics 800,600,0 Repeat If KeyHit(KEY_1) Local chan1:TChannel = PlaySound(laserfire1) SetChannelRate chan1,Rnd(.8,1.2) End If If KeyHit(KEY_2) Local chan2:TChannel = PlaySound(laserfire1) SetChannelRate chan2,Rnd(1) End If Flip Delay 5 Until KeyHit(KEY_ESCAPE)