Passing char to a function

[J-M-L]

make a smaller code demonstrating what you are trying to do. The code you posted above (please fix it with code tags) makes no sense at all

what do you expect from this?

  if (alarm_high) {
    (currentTime - previousTime >= Alarm_high) {  // ????? missing an if ?
      (playWAV('b', 3.0));
      previousTime = currentTime;
    }
  }