I can't listen the music in my iPhone

I found that I can't listen music in my IPhone neither to listen the videos in YouTube. When I try to use it in Ipod mode, the only options to listen to the music are connector dock and AirPort express. If I plug in the headphones goes to headphones mode I can listen the music again. I reset my IPhone but with the fabric configuration still has the same problem. Thank you for your help