Turn on TYY mode



Registry locations


Allowed registry values

·         0 – Lync will not use an attached TTY device

·         1 – Lync will use an attached TTY device

Registry value type


Default setting

0: TTY mode is disabled


TTY is short for “Text Telephone,” a device that enables people who have hearing and/or speech disabilities to communicate over the phone by typing and reading messages rather than by speaking and listening. (TTY devices are sometimes referred to as TDD devices: Telecommunication Device for the Deaf.) If you have a TTY device connected to your phone then Microsoft Lync can take advantage of those capabilities; all you have to do is select the option Turn on TTY mode:



You can also programmatically select (or deselect) this option by modifying the HKCU\SOFTWARE\Microsoft\Communicator\EnableTTY registry value. Setting this value to 1 enables TTY mode; setting this value to 0 disables TTY mode.


Note. There’s no “penalty” for enabling TTY mode if you don’t have a TTY device connected to your phone. If you do that Microsoft Lync will run just fine; you just won’t get any TTY capabilities.


If you’re curious as to whether TTY mode has been enabled on a computer, well, you’re in luck: the following Windows PowerShell script retrieves the current value of EnableTTY from the local computer. If you’d prefer to retrieve this value from a remote computer, simply set the value of the variable $computer to the name of that remote computer. For example:


$computer = “atl-ws-001.litwareinc.com”


Here’s the script we were just talking about:


$computer = “.”


$registry = [Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey(“CurrentUser”, $computer)

$key = $registry.OpenSubKey(“SOFTWARE\Microsoft\Communicator”, $True)


$value =$key.GetValue(“EnableTTY”,$null)

if ($value -eq 1) {$value = “Yes”}

if ($value -eq 0) {$value = “No”}

Write-Host “Turn on TTY mode: $value”


Note. If you’ve never set this value or attached a TTY device, this value won’t be present in the registry and the preceding script will return a null value. But the following script will still work to set the value, at which point the registry key will be present with a value of either 0 or 1.


You can also use PowerShell to set the value of EnableTTY. The script we’re about to show you enables TTY mode; that’s done by setting EnableTTY to 1. To disable TTY mode, set EnableTTY to 0, like so:




Here’s the script:


$computer = “.”


$registry = [Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey(“CurrentUser”, $computer)

$key = $registry.OpenSubKey(“SOFTWARE\Microsoft\Communicator”, $True)





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