How do I prevent an audio file from replaying onmouseup?

I'm simulating a piano that plays a corresponding audio file when the appropriate key is clicked.

If I allow the length of the file to run as if the piano key was sustained, and if I long-press the click, it plays the file, and then it plays again when I release the mouse. It's not noticeable if I simply click. If I instruct the audio to stop and reset its currentTime attribute on release of the mouse it doesn't do this. I wondered if there was something amiss in propagation, but I couldn't seem to pinpoint it.

const keysObj = {
  'c-key': new Audio(dir + 'key08-middleC.mp3'), 
  'd-key': new Audio(dir + 'key10.mp3'), 
...
}

let keyPlay = (key) => {
  keysObj[key.target.id].play();
}

let keyReturn = (key) => {
  const isSustained = document.querySelector("input[name='sustain']:checked");

  if (!isSustained) {
    keysObj[key.target.id].pause();
  }
  
  keysObj[key.target.id].currentTime = 0;
}

let keyPress = (note) => {
  note.onmousedown = keyPlay;
  note.onmouseup = keyReturn;
}

Solution

So I figured it out with help from the GPT, basically I just needed to pause and reset the audio time on both mouse events to prevent the audio from replaying on mouseup when the sustain is enabled.

As a bonus, using eventListeners instead of an 'on' property makes the file play cleanly instead of having the glitchy noise initially.

resetAudio = (audioFile) => {
  audioFile.pause();
  audioFile.currentTime = 0;
}

let keyPlay = (key) => {
  const audio = keysObj[key.target.id];

  resetAudio(audio);
  audio.play();
}

let keyReturn = (key) => {
  const isSustained = document.querySelector("input[name='sustain']:checked");
  const audio = keysObj[key.target.id];

  if (!isSustained) {
    resetAudio(audio);
  }
}

checkClick = (clickArea, eventType) => {
    /* 
      - handles parent/child target click to prevent k/v errors if
      the label, e.g. 'F#', is clicked instead of the body of the piano key.
      - returns new MouseEvent on correct target if label is clicked. 
      - allows keyPlay and keyReturn to still work as intended 
    */
}

let keyPress = (note) => {
  note.addEventListener('mousedown', (key) => {
    keyPlay(checkClick(key, 'mousedown'));
  });
  note.addEventListener('mouseup', (key) => {
    keyReturn(checkClick(key, 'mouseup'));
  });
}