You can configure Lync Server to instead play a simple tone instead or turn entry/exit announcements off altogether.
To set the new default entry/exit announcements to a tone, run the following cmdlet from your Lync back end server:
Set-CSDialInConferencingConfiguration -EntryExitAnnouncementsType ToneOnly -EntryExitAnnouncementsEnabledByDefault $trueNote: You must be a member of the RTCUniversalServerAdmins group or have the appropriate RBAC rights to run this command.
To disable entry/exit announcements altogether, run the following cmdlet:
Set-CSDialInConferencingConfiguration -EntryExitAnnouncementsEnabledByDefault $false