first thing to do is move the stop code to its own function:

void stop(){
 snip.close();
 minim.stop();
 super.stop();
}

o is being set to the current number of seconds since the sketch started (o = second())...but then it's immediately being set to 0 by the first part of your for() loop.  The rest of your for() loop says: add 0 to 0 until the result is greater than 1.  That will take some time, you may want to grab a cup of coffee.  ;)

you need to track the change in current time since the last tick.  So if you have a variable "lastTick", you can set it to second() -- and when the number returned by second() increments, it will be greater than lastTick.  But you have to check every frame, so this will need to be in draw().

int lastTick; // declare outside of all functions, so this is a global var
lastTick = second(); // <-- last thing in setup() so it starts off on the right second...and in draw:
if (second() > lastTick){
 [play a sound and set lastTick to = the current second()]
}

for maximum accuracy I would also recommend adding "frameRate(9999);" to setup() to break the built-in limit of 60 fps.