PLT OF AC95 TAXIED ONTO RWY WITHOUT A CLRNC AT DAL.

Narrative

AFTER TAXI; I WAS ON TWR FREQ AND UNDERSTOOD TWR TO SAY '(UNINTELLIGIBLE)...POS; HOLD BEHIND THE LNDG ACFT.' I NEVER HEARD ANYTHING LIKE 'HOLD SHORT.' APPARENTLY; WHAT I WAS ACTUALLY GIVEN WAS A HOLD SHORT INSTRUCTION. BY THE TIME I HAD RECONCILED MY INSTRUCTIONS AND WAS READY TO REPEAT THEM BACK TO THE TWR; HE WAS ALREADY TALKING TO AN ACR ACFT ON THE OTHER RWY COMPLEX. I TAXIED INTO POS AND WAS HOLDING BEHIND A LEARJET THAT HAD JUST LANDED. AFTER A COUPLE OF MINS WAITING WITH A CLR RWY AHEAD; I REALIZED I SHOULD NOT BE ON THE RWY. AT THE SAME TIME; I HEARD ANOTHER PLT WHO WAS LNDG ON RWY 13L SAY THERE WAS AN ACFT ON THE RWY. I IMMEDIATELY TAXIED OFF THE RWY. THE ARRIVING ACFT HAD TO GO AROUND. I WAS ASKED TO CALL THE TWR WHEN I ARRIVED AT MY DEST. I THINK A BIG CONTRIBUTING FACTOR TO THIS EVENT WAS THE PHRASEOLOGY 'LNDG ACFT.' IF THE CTLR INDEED SAID TO 'HOLD SHORT OF THE RWY;' HE SHOULD NOT HAVE INCLUDED ANYTHING ABOUT LNDG ACFT. 'HOLD SHORT' SHOULD SIMPLY BE 'HOLD SHORT' WITHOUT ADDITIONAL DISCUSSION. OTHER CONTRIBUTING FACTORS INCLUDE AN OLD HEADSET I WAS USING THAT DOES NOTHING TO FILTER OUT BACKGND NOISE. THE THING THAT REALLY MATTERS MOST IS I SHOULD HAVE QUESTIONED AND VERIFIED EVERYTHING I WAS TOLD. THIS WILL BE MY MANTRA IN THE FUTURE. I MUST HAVE ONLY HEARD WHAT I WANTED TO HEAR INSTEAD OF THE ACTUAL INSTRUCTIONS.