Just first speed is working and the other tracks works with first icon’s speed list! You know how to fix it to work each speedList for each track!?
const speedlist = document.getElementById("speedlist");
speedlist.addEventListener("change", changeSpeed);
function changeSpeed(event) {
audio.playbackRate = event.target.value;
}.audio-player #speedlist {
position: relative;
display: flex;
left: 1.5rem;
top: 0.1rem;
outline: none !important;
border: none !important;
background-image: url("icon/speed.png");
background-size: 100%;
background-repeat: no-repeat;
width: 3px;
-webkit-appearance: none;
appearance: auto;
}<select id="speedlist">
<option value="1"></option>
<option value="0.5">0.5</option>
<option value="1.5">1.5</option>
<option value="2">2</option>
</select>