Hey Indiemusicboy,
Welcome to the Apple Support Communities! I see you're still hearing sound coming from your iPad even when the volume is all the way down. I can appreciate how inconvenient this would be, so I wanted to reach out with some assistance.
Take a look at the article below for more information on adjusting the volume on your device.
Adjust the volume on iPad - Apple Support
If you navigate to Settings > Sounds, you can choose the option to "Change With Buttons". If this setting is enabled, the volume of the ringer and alerts can be adjusted using the volume buttons on the side of the iPad. With this setting enabled, you'll see either "Sound Effects" or "Volume" come up on the screen when you use the buttons to adjust the volume. This will depend on the application you're currently using on the iPad.
Try leaving this setting disabled, then move the ringer and alerts slider all the way to the left to mute the sound. Once you're done, hold down the Volume Down button to ensure that the standard volume is also muted.
If you're still noticing an issue after taking the steps above, I recommend restarting your iPad as a next step to see if the issue persists.
Restart your iPhone, iPad, or iPod touch - Apple Support
Cheers!