Why my phone not play any sound and also hangs.

My phone not genrating any sound like no notification sound, no ringing sound, no audio playback and when i ply youtube video is just stoped when i touch play button then again it stop just when i press play button and also some times for 1 sec sound come and then just gone and phones also hangs when it sound to produce sound and when i power up the mobile boot sound play for 2 then just gone