Why can I hear ringtones on my Iphone but not anything else?

Okay so i have an iPhone 4S and I can hear Siri, ringtones, and alarms. However, when it comes to an app (ex. Insta, youtube, Netflix, vine) I can't hear a thing through my speakers! I know they work because noise still comes out of them! Can anybody help tell me what I can do to fix this?!

Activate loudspeaker for those apps.

  • Why Can't I Hear Anything On Vine? I just got an iphone 4 and downloaded vine but i can't hear anything! And my volumes all the way up!
  • Why can't I hear anything from my iPhone 4s? I can't hear anything except when on the phone; without headphones in. The volume doesn't show up unless I have headphones in. And I've tried putting the headphones in and out fast, turning on and off, and nothing worked. My phone is up to date - iOS 5.1.1
  • Why Can't I Hear Anything When I Take A Video On My Iphone 4? I was taking a video on my phone but when I tried playing it all I heard was an annoying high pitched noise. However, my Voice recorder does work. Its just the video. It also works when I have my headphones in. I researched the problem and found out its common on the iphone 4/4s. I tried doing the microphone cleaning that seemed to work for others but didn't for me. Is there anyway to fix this? Or any apps that will allow me to record video and hear it?
  • Why can't I hear anything when I call someone? (iPhone 3GS)? I still have an iPhone 3GS and recently I have found that whenever I make a call or receive a call, I can't hear the person on the other end, but they can hear me. It doesn't work when it's on speaker or headphones either. But whenever I listen to music or sound from an app I'm hear it fine. I have tried a hard resets and I don't know what to do. How can I fix this?