please help me to find whats wrong with my iPhone 4

1) When i receive a call, loudspeaker automatically turning on…and me and other end can not hear anything(although i turn it off manually, still couldn't hear)..but when i reset the phone it will remain okay for a while…then again the same….

2)When data is on during a call.. phone get stuck and then restarting …. some times it gets stuck while pressing the end call button(stuck in call ending screen)…some times it just go blank and restarts…..

Tried restoring using i tunes…. but nothing changed…. my iPhone 4 has ios 6.01 please help me

I know this might be a hardware issue.. but can you tell your personal idea

here is my email add shehan_nonis@ymail.com