Sounds problem

I have an iphone 4s. For some reason I can't hear the notification sounds, like for email and voicemail. The ringtone and text tones seem to work intermittently. Does anyone have an idea why that happens? I haven't run the 7.1.1 update. I heard bad things about it. Could that have something to do with it? The phone worked fine before and I'm tired of getting into trouble for not responding to texts from my wife.