Took my wife, my daughter and her boyfriend up today for a short flight. Coming back to the airport to land and do all the right things call several miles out, enter on the 45 and call all my turns. Didn't see anyone or hear anyone which is not unusual at my home airport. I look before turning base and then start my turn and as I do another plane is already on base but in tighter than me and shortly after he turns final. So I go around. Come back in and land. I went over and talked to the guy. I asked was he on a non-standard pattern as I never saw him. He said nope standard pattern. I said were you on the radio because I never heard him. He said yes he was on the radio. I said did you hear me? He said yes. I said I just don't know what happened. So we talked through it a bit more. Thankfully he was super helpful as I was sincerely eager to find out where the problem occurred. So two things, I don't know how I didn't see him when entering the pattern and apparently joined the pattern relatively parallel to him. He was flying a fairly tight pattern so he was well inside me. So lesson there some times under certain circumstances planes are just hard to see if they aren't exactly where you think they are suppose to be. So look harder. So then why didn't I hear him. Finally I figured it out I had turned down the radio to explain something to my passengers a short time before that and never turned it back up. UGH!!! I apologized to the guy a couple of times. Thankfully he said he saw and heard me the whole time so there was no danger. See and avoid was working on one side any way. He just didn't know why I was doing what I was doing. Had I had the volume up I would have known he was there even though for whatever reason I didn't see him. I think not seeing him was mostly a timing thing without the audible clue he was there. Had we both been NORDO that might have been more problematic. In any case my new policy I am just not going to turn down the volume on the radio and wait for clear spots to talk. Unfortunately around here there are several fairly close airports that share a frequency and there can be a lot of chatter on a nice day like today.