The Exchange 2007 Unified Messaging server role is installed with a set of default audio prompts, and these audio file are the recordings that are used for menu prompts for Outlook Voice Access, voice mail greetings, and numbers that are used by Exchange Unified Messaging. These audio files are played by a Unified Messaging server to incoming internal and external callers. Many of the audio files are default prompts that provide the users of the telephony user interface (TUI) and Outlook Voice Access the information that they need to move through the TUI and the voice user interface (VUI). The prompts are located in <Program Files>\Microsoft\Exchange Server\. The prompts that are used by the Unified Messaging server to help callers move through the menus should not be replaced or changed. However, when an additional UM language pack is installed, the prerecorded prompts for that language will also be installed. After a UM language pack has been installed, the prerecorded prompts for that language can be used by UM dial plans and auto attendants.

Unified Messaging relies on the Text-to-Speech (TTS) engine. TTS functionality is provided by the Microsoft Speech Server service. The TTS engine reads and converts written text into audible output that can be heard by a caller. The TTS engine reads and converts the following items in a user's mailbox:

• E-mail and voice mail message bodies, subjects, and names
  
  
• Calendar item bodies, subjects, locations, and names
  
  
• Personal contact names
  
  
• The user's default voice mail greetings
  
  

Note:
After a user has recorded personalized voice mail greetings, the TTS version of their voice mail greetings is no longer used.

In addition to TTS, Automatic Speech Recognition (ASR) support is included in Exchange 2007 Unified Messaging. ASR functionality is provided by the Microsoft Speech Server service. ASR enables callers to use voice commands to interact with the Unified Messaging system. By using ASR, callers can move through menus and interact with items from their individual mailboxes, including messages, personal contacts, and calendar.

Currently, Exchange 2007 Unified Messaging includes ASR support for only the English version of Exchange 2007. Other UM language packs do not contain support for ASR. However, if you install a localized version of Exchange 2007, for example Japanese, ASR support is not included for Japanese. However, because English is always installed together with localized versions of Exchange 2007, ASR for English will work.

There are plans to include ASR support in UM language packs for other languages after Exchange 2007 has released. After new language packs have been released and after you have installed the appropriate language pack that includes ASR support for a language other than English, users will be able to use this language to interact with the Unified Messaging system by using speech input. 

You install a UM language pack on the Unified Messaging server by using Setup.com. After you have installed the new language pack on the Unified Messaging server, the language associated with the language pack will be added to the list of available languages that you can use. You can view the languages that have been installed by using the UM Settings tab on the Unified Messaging server properties in the Exchange Management Console or by using the Get-UMServer cmdlet in the Exchange Management Shell. 

Installing the UM language pack copies the files that are used by the TTS engine and the prerecorded prompts for the chosen language and makes them available when a user connects to the Unified Messaging system.

Each UM dial plan that is created contains a default language setting. The UM dial plan language setting is needed because Unified Messaging may have to use Text-to-Speech conversion or play a standard audio prompt for Outlook Voice Access users when they access their Exchange 2007 mailbox. You do not have to select a default dial plan language. However, each dial plan that is created is configured to have a default language that is based on the language version of Exchange 2007 that is installed. If you install the U.S.-English version, U.S. English will be the default language for all dial plans that are created. If you installed a localized version of Exchange, for example Japanese, Japanese will be configured as the default language when dial plans are created.

After you have created a new dial plan, you can configure the default language setting on each dial plan. If you install the U.S.-English version of Exchange 2007, U.S. English will be the only available option. You can add other UM languages to the U.S.-English version by installing other UM language packs. After you install a UM language pack on a Unified Messaging server, the language associated with the language pack will also be listed as an available option when you configure the default language for the dial plan. However, U.S. English is the default language that will be used when dial plans are created.

For example, you first install the U.S.-English version of Exchange 2007 and then install the Japanese UM language pack by using the Setup.com /AddUmLanguagePack command. Then you install another UM language pack on a Unified Messaging server, for example French. After you have successfully installed the UM language packs, U.S. English, Japanese, and French, will be available options. However, by default, U.S. English is the language that will be chosen for each dial plan that is created.

When you install a localized version of Exchange 2007, for example, Japanese, the default language for the dial plan will be Japanese. However, after you have created a new dial plan, you will be able to configure the dial plan to use either Japanese or U.S. English as the default language. When localized versions of Exchange 2007 are installed, U.S. English is also installed. For example, you first install the localized Japanese version of Exchange 2007 and then install the French UM language. After you have successfully installed the UM language pack on the localized version of Exchange 2007, Japanese, U.S. English, and French, will be available but, by default, Japanese will be the language that is chosen for each dial plan that is created.

The default language is important to callers. When an Outlook Voice Access user calls in to the Unified Messaging system, the language setting that is chosen is based on the language setting that is configured in Outlook Web Access that was set when the user first logged on to their mailbox by using Outlook Web Access. Unified Messaging then compares the language that is set in Outlook Web Access to the list of available languages on the dial plan with which the user is associated. If there is no suitable match for the language, the default UM dial plan language will be used. Sometimes, you may have to set this language as the default language. For example, if you have a dial plan that contains only users from France, you may want to change the default language setting on the dial plan to French. For more information about how to change the default language for a UM dial plan, see How to Configure a Unified Messaging Dial Plan with a Default Language.

By default, because UM auto attendants are associated with a UM dial plan when they are created, they use the default language setting of the associated UM dial plan. However, this setting can be changed after the UM auto attendant is created.

The UM auto attendant language setting is needed because Unified Messaging may have to use Text-to-Speech conversion or play a standard audio prompt to a caller. Unified Messaging does not check that the language of custom prompts for the auto attendant matches the language setting on the auto attendant. However, as a best practice, make sure that the language setting of the auto attendant matches the language of the custom prompts. Otherwise, the caller may hear the system shift from one language to another.

Being able to change the UM auto attendant language setting is also useful if you need several different language-specific auto attendants for callers. For more information about how to configure language settings on a UM auto attendant, see How to Configure the Language Setting on a Unified Messaging Auto Attendant.