Well, I think the problem is that you have if chan1, and elseif chan1. Try the code below:
Code:
on *:text:*:#:{
  if ($chan == #chan1) {
    if ($nick == me1) {
      if (hello isin $1-) { splay sound35kb.wav }
    }
    elseif ($nick == me2) {
      if (call isin $1-) { splay sound35kb.wav }
    }
  }
  elseif ($chan == #chan2) {
    if ($nick == me3) {
      if (there isin $1-) { splay sound35kb.wav }
    }
  }
}