We recently upgraded to CUCM 6.1.3(b) from 4.X. Now, we receive a buzzing kind of sound when the speakers are turned on-on a call. We tried upgrading the firmware of 7941G from SCCP41.8-4-2S to SCCP41.8-4-4S. But, we still have the same issue. Can you pl suggest solution.
You may be hitting this bug;
CSCsz68389 Bug Details
Noise Reduction causes saturated speech on Handsfree Send
When talking on the speakerphone, far end listeners may hear voice clipping. The talker's voice may sound like a buzz.
This issue is most noticeable when the talker is using the speakerphone.
The talker can sit farther away from the phone, talk in a lower voice or use the handset or headset.
Further Problem Description:
3 - moderate
In Last 2 weeks
Cisco Unified IP Phones 7900 Series
Hope this helps!