No ringtone just a hissing sound

[mg48]

For some reason my phone is only making a hissing sound instead of playing the ringtone when I receive a call. It wakes and displays the caller info dialogue correctly but all I can hear is a slight hiss from the speaker. I dont use any phone utilities other than Call Block, and use only OEM ringtones. I have had Call Block on there for sometime. If I hard reset and dont install anything it will ring. If I do a restore from Sprite backup then my problem is back.