<button class="play-button button" aria-label="Прочитать" title="Прочитать">
  <svg width="100%" height="100%" viewBox="0 0 36 36">
    <path d="M 12,26 18.5,22 18.5,14 12,10 z M 18.5,22 25,18 25,18 18.5,14 z">
      <animate attributeName="d" class="pause" attributeType="XML" dur="0.15s" begin="none" fill="freeze" from="M 12,26 16,26 16,10 12,10 z M 21,26 25,26 25,10 21,10 z" to="M 12,26 18.5,22 18.5,14 12,10 z M 18.5,22 25,18 25,18 18.5,14 z"></animate>
      <animate attributeName="d" class="play" attributeType="XML" dur="0.15s" begin="none" fill="freeze" from="M 12,26 18.5,22 18.5,14 12,10 z M 18.5,22 25,18 25,18 18.5,14 z" to="M 12,26 16,26 16,10 12,10 z M 21,26 25,26 25,10 21,10 z"></animate>
    </path>
  </svg>

    </button>

body{
  background:bisque;
}
.button {
  border: 1px #333 solid;
  border-radius:4px;
  background-color: transparent;
  padding: 0;
  color: inherit;
  text-align: inherit;
  font-size: 100%;
  font-family: inherit;
  cursor: pointer;
  line-height: inherit;
  width: 100px;
  height: 50px;
  position:fixed;
  left:calc(50% - 50px);
  top:calc(50% - 25px);
  background:darkorange;
}
.synth-controls .button {
  height: 100%;
  position: relative;
}
.play-button,
.next-button,
.prev-button {
  -webkit-box-flex: 0;
  -webkit-flex: 0 0 auto;
  -moz-box-flex: 0;
  -ms-flex: 0 0 auto;
  flex: 0 0 auto;
}
.synth-controls .button {
  cursor: pointer;
  opacity: 0.9;
  display: inline-block;
  width: 34px;
  -webkit-transition: opacity 0.1s cubic-bezier(0.4, 0, 1, 1);
  transition: opacity 0.1s cubic-bezier(0.4, 0, 1, 1);
  overflow: hidden;
  z-index: 2147483647;
}
.synth-controls a {
  color: inherit;
  text-decoration: none;
  -webkit-transition: color 0.1s cubic-bezier(0, 0, 0.2, 1);
  transition: color 0.1s cubic-bezier(0, 0, 0.2, 1);
  outline: 0;
}
.synth-controls svg {
  pointer-events: none;
  fill: #685483;
}
.synth-controls .button:hover svg {
  fill: #ad0000;
  filter: drop-shadow(1px 1px 1px #ffffff);
}

const Button = document.querySelector('.play-button');
const BtnPath = Button.querySelectorAll('svg path *');
Button.addEventListener('mouseenter',
                        function(event){
        event.preventDefault();
        event.stopPropagation();
        aCls(Button,'active');
        BtnPath[1].beginElement();
        Button.ariaLabel = Button.title = 'Пауза';
});
  Button.addEventListener('mouseleave',
                          function(event){
        event.preventDefault();
        event.stopPropagation();
        rCls(Button,'active');
        BtnPath[0].beginElement();
        Button.ariaLabel = Button.title = 'Прочитать';
});

function aCls(e,c){
  if(e.classList){
    e.classList.add(c);
  }else{
    e.className = c;
  }
} //добавить класс
function rCls(e,c){
  if(e.classList!==null){
    e.classList.remove(c);
  }else{
    e.className = e.className.replace(c, "");
  }
}  //удалить класс