Hey Josh,
Good question! Because cBarge is essentially an AdHoc Conference, this tone is related to the Conference Join/Leave Tones. To disable the cBarge tone you would have to disable the Conference Join/Leave Tones.
Barge (Conference Barge)
The Barge feature enables phone users to join a call on a shared octo-line directory number by pressing the Cbarge soft key and converting the call to an ad hoc conference. This feature uses a hardware conference bridge configured in Cisco Unified CME. When the initiator barges into a call, an ad hoc conference is created between the barge initiator, the target party, and the other party connected in the call. Parties see the call information on their phone displays and, if the conference join tone is configured, hear a tone.
http://www.cisco.com/en/US/docs/voice_ip_comm/cucme/admin/configuration/guide/cmebarge.html
SCCP: Configuring Join and Leave Tones
To configure tones to be played when parties join and leave ad hoc and meet-me conferences, perform the following steps for each tone to be configured.
SUMMARY STEPS
1. enable
2. configure terminal
3. voice class custom-cptone cptone-name
4. dualtone conference
5. frequency frequency-1 [frequency-2]
6. cadence {cycle-1-on-time cycle-1-off-time [cycle-2-on-time cycle-2-off-time] [cycle-3-on-time cycle-3-off-time] [cycle-4-on-time cycle-4-off-time] | continuous}
7. end
http://www.cisco.com/en/US/docs/voice_ip_comm/cucme/admin/configuration/guide/cmeconf.html#wpxref76692
dualtone
To enter cp-dualtone configuration mode for specifying a custom call-progress tone, use the dualtone command in custom-cptone voice-class configuration mode. To configure the custom-cptone voice class not to detect a call-progress tone, use the no form of this command.
dualtone {busy | conference | disconnect | number-unobtainable | out-of-service | reorder | ringback}
no dualtone {busy | conference | disconnect | number-unobtainable | out-of-service | reorder | ringback}
Syntax Description
busy
Configure busy tone.
conference
Configure conference join and leave tones.
disconnect
Configure disconnect tone.
number-unobtainable
Configure number-unavailable tone.
out-of-service
Configure out-of-service tone.
reorder
Configure reorder tone.
ringback
Configure ringback tone.
http://www.cisco.com/en/US/docs/ios/voice/command/reference/vr_d2.html#wp1452512
Hope this helps!
Rob
