ZID DEVELOPMENT CTLR DESCRIBED CONFUSED SIT WHEN AN ACR; ON THE WRONG FREQ WITH SIMILAR CALL SIGN; RESPONDED TO ATC'S INQUIRIES.

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MY TRAINER AND I HAD JUST SPLIT THE HIGH SECTORS FROM THE LOW SECTOR. TFC WAS JUST STARTING TO PICK UP AND WHEN WE SPLIT THE SECTOR I HAD RADAR CTL OF APPROX 9 ACFT. AN ACR REQUESTED AN ALT CHANGE FOR RIDES. I CLBED HIM. OTHER ACFT CALLED ON AND I ISSUED A CLRNC TO CLB; ANOTHER ACR OFF OF LEX GOING TO ORD. I HAD TFC FOR HIM AT FL290 SO I CLBED HIM TO FL280. AN ACFT CALLED ON FROM AREA 4 AT FL330 AND I TOOK THE HDOF ON ACR X FL330 FROM ZKC. ACR X WAS THE ONLY ACFT THAT HADN'T CALLED ON MY FREQ. THESE XMISSIONS WERE VERY GARBLED AND MIXED WITH WHAT I THOUGHT WAS MORE THAN 1 ACFT CALLING. I LOOKED AT MY TRAINER AS WE WERE LISTENING TO DETERMINE IF HE'D HEARD ANY MORE DETAIL THAN I HAD. AT THAT POINT I STATED; 'IT SOUNDS LIKE SOMEONE SAID SOMETHING ABOUT A CLB.' WHEN THE XMISSION STARTED; I HEARD 'ACR X GARBLE...(CLB)...GARBLE....' THIS XMISSION WAS MIXED AND BLOCKED BY ACR Y READING BACK HIS CLB CLRNC. MY TRAINER SAID; 'WELL; ACR CHKED ON;' POINTING TO ACR X. I'D ALSO HEARD THE WORD ACR XMITTED; 'ACR X I HAVE YOU AT FLT LEVEL THREE-THREE-ZERO.' I HEARD A REPLY; 'ACR X; THREE-THREE-ZERO.' I REPLIED; 'ROGER; WHO ELSE CALLED?' AND WAITED. I GOT NO ANSWER AND SCANNED MY DATA BLOCKS WONDERING WHO SAID THE WORD 'CLB' AND WAS VERIFYING NO ONE WAS CLBING OTHER THAN THE 2 ACFT I HAD PREVIOUSLY CLRED FOR CLBS. HE RPTED BACK THE CORRECT ASSIGNED ALT. NO OTHER ACFT SAID ANYTHING ABOUT REQUESTING A CLB OR ANYTHING ELSE. APPROX 10 MINS LATER; I WAS PAGED AND TOLD I WORKED AN ACFT THAT MAY HAVE GOTTEN WITH ANOTHER ACFT IN ZKC OR ZMC'S AIRSPACE. WE WENT TO THE E-DESK AND THE MGR TOLD ME I PROBABLY HAD AN AIRSPACE VIOLATION. HE SAID THAT THE ZME CTLR SAW THAT A PLANE WAS CLBING AND TURNED HIS TFC SO THE 2 ACFT DIDN'T LOSE SEPARATION. ZKC WAS ALSO LISTENING TO TAPES AND THIS IS WHEN I FOUND OUT ACR X HAD MISTAKENLY CALLED ON MY FREQ. THE OPS MGR TOLD US THAT THE ZKC CTLR HAD BOTH ACR Y AND ACR Z ON HIS FREQS. THE ZKC CTLR NEVER ADVISED THE 2 ACFT THAT HE HAD THEM BOTH AND TO USE CAUTION WITH SIMILAR SOUNDING CALL SIGNS. WE LISTENED TO THE RECORDINGS SEVERAL TIMES BUT THEY SOUND VERY DIFFERENT FROM WHAT THE FREQS SOUNDED LIKE. I ASKED ABOUT THIS AND THEY TOLD ME THAT THE FREQS ARE RECORDED SEPARATELY AT THE CONSOLE. THIS RECORDING IS NOT WHAT IS COMING THROUGH THE CTLR'S HEADSET. THE RECORDINGS WERE DIGITALLY REPLAYED AND RUN AT THE SAME TIME. ON 'TAPE;' THEY ARE VERY CLR BECAUSE NEITHER ACFT IS CANCELED BY ANOTHER XMISSION. THE MGRS ACTED AS IF THEY DID NOT BELIEVE MY DESCRIPTION OF WHAT I HAD HEARD. BUT THERE WERE 3 PEOPLE PLUGGED IN AND NONE OF US HEARD THE EXACT EXCHANGE BECAUSE OF THE CANCELED XMISSIONS. ON THE RECORDING; ACR X CHKS O 'CLBING OUT OF 22X FOR FLT LEVEL TWO-SEVEN-OH.' AT THE SAME TIME ON THE OTHER FREQ; THE ACR Y WAS READING BACK HIS CLRNC TO CLB TO FL310. THE RECORDINGS ARE NOT BLOCKED AND ARE VERY STRONG AND CLR. ALSO; IT SOUNDED LIKE ACR X RECORDING WAS MORE PROMINENT THAN THE ACR Y. THIS ALSO WAS OPPOSITE IN MY HEADSET. SO; AFTER A PAUSE ON THE FREQ WHEN MY TRAINER AND I WERE DISCUSSING WHO CALLED; MY NEXT XMISSION IS 'ACR X; I HAVE YOU AT FLT LEVEL THREE-THREE-ZERO.' ACR X REPLY IS 'ROGER; ACR X CLBING TO FLT LEVEL THREE-THREE-ZERO.' I REPLY; 'ROGER; WHO ELSE CALLED?' THERE WAS NO REPLY. I WAS TOLD A FEW HRS AFTER THIS BY THE CTLR WORKING THE PXV/IMP SECTOR THAT AFTER I LEFT; ABOUT 10 MINS OR SO LATER HE WAS CALLED 'OUT OF THE BLUE' BY AN ACR Z ASKING IF HE WAS ON THE RIGHT FREQ. THE CTLR SAID THE PLT SOUNDED VERY UNSURE OF HIMSELF. THE CTLR LOOKED HIM UP IN URET AND GAVE HIM THE CORRECT ZME FREQ. IN ALL; SEVERAL THINGS HAPPENED HERE BESIDES THE MISTAKE OF DUAL EXPECTATIONS. THE RECORDING EQUIPMENT AND THE LIVE BROADCASTS WERE VERY DIFFERENT. I ALSO SHOULD HAVE FOLLOWED MY INSTINCTS WHEN I HEARD 'CLB;' I SHOULD HAVE ASKED AGAIN SPECIFICALLY WHO SAID SOMETHING ABOUT CLBING. I THOUGHT I'D COVERED MY BASES WHEN I KNEW THE ACR Y READ HIS CLRNC BACK AND I VERIFIED WITH THE ONLY OTHER ACFT IN MY AIRSPACE THAT I KNEW OF; THE ACR WAS CLBING TO HIS ASSIGNED ALT. THE ACR X PLT SHOULD HAVE QUESTIONED ME WHEN I SAID AN ALT DIFFERENT FROM WHAT HE HAD JUST RPTED TO ME. MAYBE HE ALSO SHOULD HAVE SAID SOMETHING WHEN ACR X CALLED ON AND I ANSWERED THAT ACFT AND ADDITIONALLY NEVER TOLD THEM TO USE CAUTION BECAUSE OF SIMILAR SOUNDING CALL SIGNS. MY TRAINER ALSO COMMENTED AFTER HEARING THE RECORDINGS THAT MAYBE HE LED ME TO BELIEVE THAT THE ACR LOOKING FOR WAS THE ONE THAT CALLED. HE SAID MAYBE I SHOULD HAVE JUST WAITED FOR THE ACFT TO CALL AGAIN. THIS IS CORRECT BUT GIVEN THE INFO THAT WE HAD; THE ONLY PLANE WE WERE WAITING FOR WAS ACR X; THAT IS WHAT WE WENT WITH.