Hi,
Please check the following:
1. Please check if you are on supported hardware and that no co-resident VMs exist:
http://www.cisco.com/c/en/us/td/docs/collaboration/CWMS/2_0/Planning_Guide/Planning_Guide_chapter_01011.html#reference_249B138B71324D19B09141D3849EC058
2. Check if you have any snapshots on any of the virtual machines for the system. If you have captured any snapshots before an upgrade, make sure that you delete them within 24 hours as they cause degradation of system performance and are known to cause audio quality issues.
3. Please check your network bandwidth for these requirements:
http://www.cisco.com/c/en/us/td/docs/collaboration/CWMS/1_5/Planning_Guide/Planning_Guide_chapter_01.html#reference_267DB686BB224EB7A49DE4C783C912E6
If you still face the problem, please open a TAC case to troubleshoot the issue further. We will be able to get detailed logs and sniffers to find the cause of the issue.
Thanks,
Jyothi