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Philips Speech Extensions guide

Known issues

In the following sections, you´ll find some general known issues occurring on multiple platforms.

There are also some known platform-specific issues, which are not listed here, but in their respective setup sections.

General issues when using Citrix

Starting with Citrix Virtual Delivery Agent 2109 by default, the Virtual channel allow list feature is enabled. As a result, only Citrix virtual channels are allowed to open in virtual apps and desktop sessions. If there is a need to use custom virtual channels like Philips control or Philips audio virtual channel, these need to be explicitly added to the allow list or – alternatively - the policy can be disabled.

To disable the policy, open your Citrix Studio and go to Policies. Edit/Create a policy and set the Virtual channel allow list value to Disabled:


If disabling the policy is not possible (e.g. for security reasons), Philips virtual channel names need to be added to the Virtual channel allow list. Furthermore, starting with Citrix Virtual Delivery Agent 2402, the path to the application´s executable from which these channels are used needs to be added. These might be 3rd party applications like Nuance DMO or Philips software like SpeechExec.

For defining the contents in the Virtual channel allow list follow this manual: Virtual channel allow list and contact us via for further assistance how to configure the allow list exactly.

General issues on Linux

As audio USB devices plugged into USB 3.0 ports on Linux clients can lead to malfunction, USB 3.0 ports are not supported on clients where Linux based operating systems are running. Please use USB 2.0 ports for your dictation devices.

General issues on VMware Horizon View

  • Supported protocols are PCoIP and VMware Blast, however, due to a change in the PCoIP protocol, DPM and SpeechAir devices are only supported with the VMware Blast protocol.

  • SpeechMike/SpeechOne firmware update is currently not supported in a VMware Horizon View environment.

  • Using a DPM device as a USB microphone is currently not supported in a VMware Horizon View environment.

  • VMware Horizon requires the built in DPM AutoPlay suppression to be disabled, which can be done with the following registry key, which has to be created on the target/server: The following registry value will turn off the feature for 32 bit DPMCtrl on 64 bit OS: [HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Philips Speech\DPMCtrl] "CancelAutoPlay"=dword:00000000 The value can also be created in the HKEY_CURRENT_USER (which has precedence) or in the 64 bit registry if necessary for a 64 bit integration. On 32 bit OS the WOW6432Node\ should be omitted, of course.

General SpeechExec Enterprise issues

  • DPM authors with either small letters (author) or mixed upper and lower case letters (Author) cannot be downloaded automatically by SpeechExec Enterprise in a WTS/RDP session. Workaround: please define Authors in the DPM with capital letters only (AUTHOR). That will assure the automatic DPM download in SpeechExec Enterprise.

  • The following SpeechExec Enterprise functions are not available on any virtual platform:

    • Recording notification beep

    • Recording standby beep

    • Playback of .wma file format

    • Playback of .mp3 VBR file format

    • Changing the preferred playback device for playback through SpeechExec

    • Some limitations in the SpeechMike configuration wizard

  • SpeechExec Enterprise version 7 or later uses Nuance Speechkit for online speech recognition. For SpeechKit, the Supported platforms matrix is not valid in regards to supported Linux clients. SpeechKit only supports IGEL OS and eLUX.

Miscellanoeous issues

  • If connecting to a Windows Server VM in Microsoft Azure via WTS/RDP, remote audio recording might not work as expected. A possible solution for this is to modify the RDP file provided by the Azure resource. Try removing the line “administrative session:i:1”

  • If the target OS is Server 2012R2, it is required to enable the Desktop Experience feature

  • When using Nuance software integrating Philips Hardware SDK version 4.4.441 or 4.5.450.13 (e.g. Dragon Medical One 2021.4) in a remote environment, Philips client extensions (if used) must be version 4.4.441 or later. Otherwise, button events from Philips dictation devices are not received by the Nuance software. This issue can also be resolved by upgrading Philips SDK and target extensions to version 4.6 or later.

  • Connecting to Azure Virtual Desktop from the “Microsoft Remote Desktop” app in the Microsoft store is not supported by the Philips client extension drivers. Please use the Remote Desktop client for Windows instead.

  • Upgrading the VMware Horizon Client or Citrix Workspace app on Windows does usually not break Philips Speech Extensions, unless the upgrade is done by uninstalling the old VMware or Citrix client first. In this case, after installing the new VMware or Citrix client, Philips client extension drivers need to be installed again (run \2_Windows_clients\philips_client_extension_setup.exe from the Philips Speech Extensions package)