I hope that play-speed can be changed by mouse scroll while
playing audio file.
I have set default play-speed to "-speed 1.5" to watch video quickly
to save time. You can change play-speed by mouse scroll on the
video window while playing video if you want to play slowly.
In the case you listen music, play-speed shall be 1.0 basically.
But play-speed can't be changed by mouse scroll while playing audio.
If you want to change, you need to click menu several times.
It takes time.