This issue occurs when the call is to a Microsoft Lync 2013 user or to participants in a conference that is hosted in Microsoft Lync Server 2013.
This issue occurs on a Windows 7-based computer that has a processor that was released within the last three years, such as an Intel Sandy Bridge, Ivy Bridge, or Haswell processor. This issue occurs when the computer has an Intel graphics driver in a range from version 10.18.10.3650 to 10.18.10.3907 installed.
To resolve this issue, install the following update:
2899507 November 11, 2014 update for Lync 2013 (KB2899507)
The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.