Extension| trig | 
 [ar kr] starts a vosim pulse when a transition from non-positive to positive occurs and no other vosim is still going. audio rate input will produce sample accurate triggering.  | 
| freq | 
 [ar kr] the frequency of the squared sinewave.  | 
| nCycles | 
 the number of squared sinewaves to use in one vosim pulse. nCycles gets checked when VOSIM receives a trigger.  | 
| decay | 
 the decay factor.  |