C170 PLT TAKES OFF MIC WITHOUT PROPER CLRNC.

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I HAD TAXIED TO RWY 32R UNDER GND CTL. AFTER COMPLETING RUN-UPS; I SWITCHED TO TWR FREQ AND WAITED SEVERAL MINS FOR OPEN COM SPACE AS TWR CTLR WAS VERY BUSY. I RPTED 'ACR X; READY FOR TKOF.' CTLR REPLIED INSTANTLY; 'ACFT X CLRED FOR TKOF.' IN RETROSPECT; THE REPLY WAS TOO QUICK AND THE NUMBER PRIOR TO 'X' MAY HAVE BEEN STEPPED ON; BUT I READ IT AS MY CALL SIGN. I ASKED IF I WAS CLRED FOR TKOF; BUT RECEIVED NO REPLY FROM THE CTLR. I THEN READ BACK AS; I UNDERSTOOD; THE CLRNC 'ACFT X CLRED FOR TKOF; RWY 32R.' THERE WAS NO OBJECTION TO MY READBACK FROM THE CTLR. AS A LIFE-LONG HABIT; I HAVE NEVER ACCEPTED A TKOF CLRNC WITHOUT MY OWN VISUAL CHK; SO AS I TOOK THE RWY; I DID MY USUAL S-TURN TO CHK THE APCH PATH/GS AND SAW ACFT #2 ON ABOUT 1/2 MI FINAL. I JUDGED THIS AS CLOSER THAN I LIKE; BUT WITHIN THE BAND OF TOLERANCE RECEIVED AT THIS ARPT IN THE PAST. AT OTHER TIMES; UNDER SIMILAR CONDITIONS; I HAVE BEEN ASKED TO 'EXPEDITE' MY TKOF. AFTER SEEING THE OTHER ACFT; I WAS SURPRISED I HADN'T BEEN ASKED TO EXPEDITE; BUT I SWEPT OUT OF MY 'S' CHK TURN INTO AN IMMEDIATE TKOF. HOWEVER; I GOT A CALL FROM THE CTLR WHEN I WAS AT ABOUT 100 FT ALT SAYING I HAD BEEN ORDERED TO HOLD AND INFORMING ME OF THE ABORT. I MONITORED THE TWR FREQ FOR SOME TIME FOLLOWING THIS INCIDENT AND NOTED ANOTHER ACFT; WITH SIMILAR CALL SIGN WAS ACTIVE IN THE PATTERN. IN RETROSPECT; THIS COULD HAVE BEEN A RELATED FACTOR. I CALLED THE TWR CTLR FROM MY DEST; AUW; APPROX 2 HRS LATER. SHE TOLD ME SHE HAD HEARD MY REQUEST FOR CLRNC CONFIRMATION AND MY 'CLRED FOR TKOF RWY 32R' READBACK; BUT HAD NOT RESPONDED BECAUSE SHE WAS BUSY WITH 'ANOTHER SIT' ON DOWN-LEG OF THE PATTERN. THE TWR CTLR SEEMED PARTICULARLY BUSY WITH VERY LITTLE COM TIME SPACE. I HAD NO TIME PRESSURE AND COULD HAVE AND SHOULD HAVE WAITED FOR A SECOND CLRNC. I MAY HAVE BECOME SNARED IN THE 'RUSH; RUSH' ENVIRONMENT OF THE MOMENT.