A B737-300 CREW; ON APCH TO ORD; WERE GIVEN AND RESPONDED TO A CLRNC MEANT FOR ANOTHER ACFT WITH A SIMILAR CALL SIGN.

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ON APCH TO RWY 9R ORD; 1 MI W OF DEANA OM; APCH CTL CALLED 'ACR X ABCD O'HARE.' WE ANSWERED WITH 'ACR X ABCD' THEN THE CTLR ISSUED THE FOLLOWING CLRNC: 'ACR X ABCD; TURN R; MAINTAIN 180 KTS.' WE ACKNOWLEDGED THE CLRNC AND COMPLIED. WE HAD TO WAIT 30 SECONDS OR SO TO ASK FOR AN ALT; DUE TO FREQ CONGESTION. WHEN WE WERE ABLE TO TALK TO ATC; IT BECAME APPARENT THAT HE WAS UNSURE OF OUR POS. ONCE HE HAD ACQUIRED US; WE WERE GIVEN A CLB TO 5000 FT AND VECTORS BACK TO DOWNWIND FOR ANOTHER APCH. DURING THIS TIME WE HEARD AN ACR X ABDC ON FREQ. WE BELIEVE THAT THE CTLR TRANSPOSED THE LAST 2 DIGITS AND GAVE US THE INTENDED FOR ACR X ABDC. DUE TO THE TONE OF HIS VOICE AND OUR PROX TO THE ARPT; WE COMPLIED WITH THE CLRNC IMMEDIATELY AND WORKED ON CLARIFICATION. THE HUMAN FACTORS ISSUES APPEAR TO BE SIMILAR CALL SIGNS THAT I FEEL CAN BE ADDRESSED BY THIS AIRLINE AND THE CTLR APPARENTLY WAS UPSET THAT A CALL WAS MISSED BY THE OTHER ACFT AND IN THIS SIT; HE MISSPOKE THE CALL SIGN WITH MORE URGENCY THAN MAY HAVE BEEN NEEDED; CAUSING WHAT COULD HAVE BEEN A DANGEROUS SIT.