Toyota Echo Wiring Shortage from Steering Area

Hi. While driving my 2000 Toyota Echo this morning, a strange and very brief buzz started occurring from my steering wheel area. Sounds like a wire shortage to me. Occurs very randomly, sometimes just one buzz for a 5 minute period, then 6 buzzes within a 2 minute period. I tried out my horn, blinkers, my car starts fine, no problems with my steering wheel (that I know of, anyway). My radio has no sound, and has had no sound in the warmer months for the past 3 years. The radio works, but there is no sound until winter comes along. Could this be related? This week is the first really warm week we have had, which makes me wonder if these are connected. Anyone have any thoughts or advice on how I could check what wire is my problem?