The Airpods does not have any physical controls for users to control volume of change tracks; hence you will have to ask Siri to assist in doing so. It can be real annoying though because, if you are listening to a song and you want to turn the up the volume. You will have to:
- double tap on any of the Airpods to activate Siri,
- your music will than pause, and then
- tell Siri to turn up the volume of the music you are listening
If that method gets you all worked up, adjust the sound on the iPhone with the volume buttons. If you want to change the track, you will have to do so with the on-screen controls on your iPhone.