DEP CTLR ISSUED CLIMB AND VECTOR TO THE WRONG ACFT.

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WE HAD EXPERIENCED CONFUSION OVER OUR CALL SIGN; ACR AAYZ AND ACR ABYZ DURING TAXI AT ORD. ON THIS DAY WE WERE EXTRA VIGILANT; AS ACR ABYZ WAS 2 ACFT AHEAD OF US FOR RWY 9L. THE TWR HAD A LITTLE TROUBLE WITH THE ACR ABYZ CALL SIGN WHEN CLRING HIM TO DEP CTL. HE THEN CALLED US ACR AAZZ. THE F/O CORRECTED THE TWR. AFTER TKOF; AROUND 3000' MSL; DEP CLRED US TO TURN TO 220 DEGS AND CLB TO FL230. THEN WE HEARD ACR ABYZ CLRED TO TURN TO 220 DEGS AND 14000'. I COMMENTED TO THE CREW IT WAS ODD THAT ACR ABYZ WAS CLRED TO A LOWER ALT THAN WE WERE. THEN WE HEARD THE CTLR AND THE SUPVR TELL US TO STOP CLB AND STOP TURN. WE WERE ABOUT 210 DEGS AND 6000'. WE WERE TOLD TO TURN TO 180 DEGS AND MAINTAIN 6000'. THE SUPVR CHASTISED US ABOUT LISTENING FOR OUR PROPER CALL SIGN. WE RESPONDED THAT ALL 3 OF US HAD HEARD ACR ABYZ CLRED TO 220 DEGS AND FL230. SHORTLY AFTERWARD; THE CTLR CLRED US TO 14000' AND 220 DEGS. I KNOW WE CAN DO BETTER THAN 2 LENGTHY AND YET SIMILAR CALL SIGNS DEPARTING AT THE SAME TIME. EVEN EXTRA VIGILANCE CANNOT ALWAYS COUNTERACT A WELL-LAID TRAP.