I don't want to preload sounds to keep page loading costs down. On Qt 5.10.1 I can do this by setting Audio.autoLoad to false. On Qt 5.15.0 on the same machine nothing is played when calling play() method if autoLoad is set to false. Doesn't matter if the clip is wav or mp3.

import QtQuick 2.0
import QtMultimedia 5.0

MouseArea {
    onClicked: audio.play() // no audio gets played

    width: 100
    height: 100

    Audio {
        id: audio
        autoLoad: false
        source: "clip.mp3"
    }
}