C172 PLT HAS NOISES IN HEADSET AND SMELLS SMOKE. HE TURNS BACK TO LAND BUT HAS LOST COM. HE SQUAWKS 7700 AND MAKES EMER LNDG.

Narrative

I TOOK AN AIRPLANE TYPE C172 FROM FBO IN DUPAGE ARPT FOR A XCOUNTRY FLT (TRAINING FLT); HDG TO EDGAR COUNTY ARPT NEAR PRG; IL. APPROX 10 MINS AFTER DEP ON A HDG OF 170 DEGS AND AN ALT OF 3500 FT MSL; I HEARD UNUSUAL NOISES IN MY HEADSET; WHICH DISAPPEARED AFTER 1 MIN. I CONTACTED DPA TWR FOR RADIO CHK AND FOUND OUT THAT THE COM WAS STILL OK. FLYING OVER GREATER KANKAKEE ARPT I SMELLED SMOKE AND HEARD THE SAME NOISES IN MY HEAD SET. I TURNED THE NAV SWITCH OFF AND TURNED BACK FOR LNDG IN IKK. ON A HDG OF 360 DEGS; I TURNED THE NAV SWITCH ON AND THE RADIOS WORKED FINE. I DECIDED TO FLY BACK TO DUPAGE ARPT. BEFORE ENTERING THE CLASS D AIRSPACE OF DUPAGE I NOTICED THAT I LOST COM AND SQUAWKED 7700 (FOR LOST COM). I TRIED TO REACH DPA TWR ON MY MOBILE PHONE DURING THE FLT BUT I WAS NOT ABLE TO HEAR THEM. SMOKE CAME OUT OF THE AUDIO PANEL AND I DECIDED TO LAND 'IN EMER' ON RWY 15 AT DPA. I BECAME SCARED THAT I MIGHT GET FIRE IN THE CABIN. AFTER THE LNDG I CONTACTED THE TWR OF DPA ARPT AND EXPLAINED THE EMER.