It is surprising how many times the problem you describe is for the reason Napoleon mentioned above. If that was your problem, don't feel bad, you are not alone. Aside from that, the volume settings for the built in ringer and earpiece are adjustable using the volume buttons on the left side of the phone, near the top. The uppermost button raises the volume and the lower one lowers the volume. The volume of the built in earpiece is generally quite good and on some calls I need to lower it somewhat. The ringer volume is another story however and is the only complaint I have ever had with all of my iPhones I have owned. Re-recording the ringer tones used for the ringer, at a higher volume, has helped but is not the answer. The audio power to the speaker, on the bottom of the phone, is simply not enough. (are you listening Apple?) If I am wearing a coat, I won't hear the phone; if my wife has the phone buried in her purse, she won't hear it. I had a Motorola Q, before I got into the iPhones, that would practically wake the dead when it rang.