Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.4.14)
// Compass (v1.0.3)
// ----


$listOfSizes:(
	(25px, 2px),
	(20px, 2px, small),
	(30px, 3px, big)
	
);


$listOfAnimationTime:(
	(1000ms, -525ms),
	(467ms, -430ms),
	(462ms, -628ms),
	(700ms, -745ms),
	(467ms, -189ms),
	(600ms, -185ms)
);

h1{
  @each $height, $width, $label in $listOfSizes{
    @if($label){
      &.#{$label}{
        height: $height;
        width: $width;
      }
    }@else {
      height: $height;
      $t: 0;
      @for $i from 0 through 5{
        font-size: $i;
        &:nth-child(#{$i+1}){
              font-size: nth(nth($listOfAnimationTime, $i+1), 1);
							left: $t;
							$t: $t + $i + $width + 1;
							-webkit-animation: soundbarsPlay1#{$label} 1000ms -525ms linear infinite alternate;
							animation: soundbarsPlay1#{$label} 1000ms -525ms linear infinite alternate
						}
      }
    }
    
  }
}

SassMeister-output.css

h1 {
  height: 25px;
  font-size: 0;
  font-size: 1;
  font-size: 2;
  font-size: 3;
  font-size: 4;
  font-size: 5;
}
h1:nth-child(1) {
  font-size: 1000ms;
  left: 0;
  -webkit-animation: soundbarsPlay1 1000ms -525ms linear infinite alternate;
  animation: soundbarsPlay1 1000ms -525ms linear infinite alternate;
}
h1:nth-child(2) {
  font-size: 467ms;
  left: 3px;
  -webkit-animation: soundbarsPlay1 1000ms -525ms linear infinite alternate;
  animation: soundbarsPlay1 1000ms -525ms linear infinite alternate;
}
h1:nth-child(3) {
  font-size: 462ms;
  left: 7px;
  -webkit-animation: soundbarsPlay1 1000ms -525ms linear infinite alternate;
  animation: soundbarsPlay1 1000ms -525ms linear infinite alternate;
}
h1:nth-child(4) {
  font-size: 700ms;
  left: 12px;
  -webkit-animation: soundbarsPlay1 1000ms -525ms linear infinite alternate;
  animation: soundbarsPlay1 1000ms -525ms linear infinite alternate;
}
h1:nth-child(5) {
  font-size: 467ms;
  left: 18px;
  -webkit-animation: soundbarsPlay1 1000ms -525ms linear infinite alternate;
  animation: soundbarsPlay1 1000ms -525ms linear infinite alternate;
}
h1:nth-child(6) {
  font-size: 600ms;
  left: 25px;
  -webkit-animation: soundbarsPlay1 1000ms -525ms linear infinite alternate;
  animation: soundbarsPlay1 1000ms -525ms linear infinite alternate;
}
h1.small {
  height: 20px;
  width: 2px;
}
h1.big {
  height: 30px;
  width: 3px;
}