RWY INCURSION.

Narrative

RENTED GA C-172. ACFT HAD HEADSET AND BOOM MIKE. I DID NOT FULLY UNDERSTAND OP; EVEN THOUGH I TESTED PRIOR TO TAXI AND FELT COMFORTABLE. AS I TAXIED OUT; I HAD DIFFICULTY WITH GND CTL UNDERSTANDING MY XMISSIONS. ON TAXI OUT TO RWY 14 AT ILG; DID NOT SEE ANY TAXIING SIGNS FOR TXWY SIGNS FOR TXWY 'K.' I ASKED FOR PROGRESSIVE TAXIING INSTRUCTIONS BUT THEY WERE NOT GIVEN. PRIOR TO RWY 14 AT 'K' I CALLED TWR AND RPTED READY. MY PERCEPTION WAS I WAS CLRED ONTO THE RWY FOR POS AND HOLD. THE CTLR CLRED ME LATER TO TKOF BUT SAID NEXT TIME CALL BEFORE YOU TAKE AN ACTIVE RWY. NO CONFLICT NOTED. WHEN CLRED FOR TKOF I TOOK OFF HEADSET; WENT TO OVERHEAD SPEAKER; AND THERE WAS NO FURTHER CONFUSION WITH MY COMS. I SHOULD HAVE DISCONTINUED USE OF THE HEADSET AND BOOM MIKE AT THE FIRST SIGN THAT I WAS NOT ABSOLUTELY SURE THAT ALL OF MY COMS WERE BEING RECEIVED BY ME AND TRANSMITTED PROPERLY. APPARENTLY THE CONFUSION WAS COMPLICATED BY THE FACT THAT I WAS RECEIVING SOME OF THEIR RADIO CALLS AND THEY WERE RECEIVING SOME OF MINE. AS FAR AS PULLING ONTO THE RWY; I THOUGHT I HEARD HIM GIVE ME PERMISSION AND HOLD ON RWY 14.