On iPhone 4S with iOS 7.0 some of my apps no longer have any sound. I don't want to update my iOS or replace my phone. I can still play music on my phone and VO and Siri both work fine so it does not seem to be the phone or hardware. Its just sound effects on some games and such. Tried reboot (turning phone off then on again) did not help.
Try reinstalling the apps
Have you tried deleting the apps for which there is no sound and then reinstalling them? Yes, I know; data is lost. But if the lack of sound bothers you enough, I presume you'd put up with this in order to get sound back.
Did you check your mute
Did you check your mute switch on the side of the phone? Sounds like that problem
It was the mute switch! Thank
It was the mute switch! Thank you so much! I knew that was there but forgot what it did. Must have gotten toggled on by mistake. Whew! Thanks!