FLT CREW OF B737 INBOUND TO ISP EXPERIENCED INTERMITTENT TOTAL LOSS OF COMS WITH GND AND CABIN. SQUAWKED 7600 AND MADE XMISSIONS IN THE BLIND WHEN UNABLE TO COMMUNICATE.

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WHILE I WAS BRIEFING THE ILS RWY 6 APCH INTO ISP; THE FO INFORMED ME THAT I MAY HAVE A STUCK MIKE. I DISCONTINUED THE BRIEFING AT THAT TIME. THE FO AND MYSELF MADE MULTIPLE RADIO CALLS TO ZNY ON VHF #1 AND VHF #2. ALL CALLS WERE SUCCESSFUL. THE FO TRIED TO CONTACT ISP TWR ON VHF #2 AND WAS SUCCESSFUL. HE INFORMED ISP TWR THAT WE WERE HAVING RADIO PROBS AND THAT WE HAD LOST CONTACT WITH ZNY. CONTACT WITH ISP TWR WAS ALSO LOST AFTER THE FIRST 2 XMISSIONS. WE SWITCHED VHF #2 BACK TO ZNY FREQS; BUT WE WERE UNABLE TO MAKE CONTACT. WE TRIED USING ALL 3 AUDIO SELECTOR PANELS IN BOTH NORMAL AND ALTERNATE MODE WITH NO SUCCESS. TRIED UNPLUGGING THE HEADSETS; HAND MIKES AND RESETTING 1 STATION AT A TIME WITH NO SUCCESS; TO INCLUDE #3 OBSERVER AUDIO PANEL AND MIKE. WE CHKED FOR POPPED CIRCUIT BREAKERS; BUT ALL WERE IN. EVENTUALLY THE FO WAS ABLE TO MAKE RADIO CONTACT WITH ZNY ON VHF #2. AGAIN MADE APPROX 2 RADIO CALLS (XMISSIONS) AND LOST CONTACT. THE VHF #2 RADIO APPEARED TO BE OPERATIONAL APPROX 10% OF THE TIME. I (CAPT) HAD NO COM CAPABILITIES AT ALL; EXCEPT TO LISTEN VIA VHF #2 SPEAKER WHEN WORKING. WE RECEIVED A CLRNC TO CROSS 10 NM S OF CCC VORTAC AT 7000 FT AND LOST COM AGAIN. COM WAS RE-ESTABLISHED AT APPROX 6 NM S OF CCC AND WE WERE GIVEN A HEADING OF 220 DEGS AND TO DSND TO 3000 FT FOR DOWNWIND RWY 6 AT ISP. ONCE AGAIN RADIO CONTACT WAS LOST AND WE WERE UNABLE TO RE-ESTABLISH. WE WERE ALSO UNABLE TO COMMUNICATE WITH THE FLT ATTENDANT VIA THE INTERPHONE; PA OR THE CALL CHIMES. ALL THESE ITEMS WERE INOP. (AFTER LNDG; THE FLT ATTENDANTS INFORMED US THAT THEY ALSO COULD NOT CALL THE FLT DECK AND THAT THEIR PA SYS DID NOT WORK FROM EITHER STATION.) WE SQUAWKED 7600 AND TURNED BASE AND FINAL TO RWY 6 AT ISP AT APPROX 5 NM OUTSIDE THE MARKER; AND MADE POS RPT IN THE BLIND. AT THE MARKER WE TUNED IN ISP TWR FREQ; AND MADE POS RPTS IN THE BLIND. AT APPROX 1000 FT AGL ALL COMS APPEARED TO RETURN TO NORMAL. WE RECEIVED LNDG CLRNC FROM ISP TWR AND LANDED ON RWY 6 UNEVENTFULLY. WHILE TAXIING TO THE GATE; ISP TWR INFORMED US THAT ZNY AND APCH COULD HEAR US XMITTING OUR POS RPTS; BUT THAT WE COULD NOT RECEIVE.