Sony Xperia U - Inbound Call Question?

Hi All When somebody calls me, I keep missing the phone because it doesn't ring for long enough, a simple question but I just don't know how to do it on my phone, how do you make the call ring for longer. Can you give me a step by step guide on how to make my phone ring for longer. Thanks in advance. P.S. I have already looked online, asked google, and even gone through ALL of my SETTINGS on my phone, so don't say "look through your settings" ive already tried this.