Possible Solution I can't be sure this will fix everyone's issues, but I was having trouble getting sounds, alerts, and various notifications to play after an update to iOS 15.8 on my 7th-generation iPod Touch. I sent the following message to Apple but it will be sent as a bug report, too: Since the recent 15.8 upgrade, volume buttons on the side of my iPod Touch 7 make sound in Sounds > Settings but nothing outside iOS settings. The slider shows a red bell with a line through it and no sound no matter how much the slider (visually) moves up + down. I went into Settings > Sounds > Ringer and Alerts. There is a button below the volume slider > Change with Buttons. If it's ON (green, darker, or color background), turn it off. Quit out of Settings and use the volume buttons to turn the volume up and down again. You should now hear sounds you've set for your ringer or a similar alert sound, and see the side volume slider again but without the Mute icon. Test it out with other alert sounds to be sure. If you're still having issues with your alert sounds, double-check your Accessibility settings. You may not have changed anything, but it's a good idea to be thorough. Double-check any settings that have to do with sound(s) or alerts. Good luck!

Better Solution Than My Previous One I'm embarrassed to admit this, but I've found a better solution here: https://www.youtube.com/watch?v=2OZmm_fP1IA There's a Silent Mode button hidden in the control panel settings: Settings > Control Panel. Scroll down to Silent Mode. Move it into/to the top of the Included Controls list. Quit out of Settings and open the Control Panel, slide your thumb from the very bottom to the top on most screens. In the first row below the first couple of groups of icons such as Airplane Mode settings, Focus, and Home—depending on your settings—should be the Silent Mode button. It's a bell icon, sometimes in red or another color depending on your settings, with a line through it. Disable it. It should now be a bell icon with no line and the color will change to white or the alternate color set up in your settings. Quit out of Settings. This solution is thanks to Jacob Drozh, and his YouTube username is: @JacobDrozh (I can't use the YT link here because of the format). Thanks Jacob!