Speech Engine on Asterisk Release Notes

9.1 (October 2009):

The LumenVox products now support licensing authentication, allowing for the License Server to only provide licenses to clients who authenticate with a user name and password. You can use this if you wish to provide licenses to customers over the public Internet, or to take advantage of our new subscription licenses.
American English (en-US) now has three different resolution acoustic models you can use. These models offer better accuracy, but use more memory and require more time for decodes. By default, only the lowest resolution model is loaded.
We have removed the "-di" suffix in a language declaration to indicate that digits-only acoustic models should be used. The Engine will now make this switch automatically, if it detects that that all loaded grammars use only digit words. This should offer much greater compatibility when using the built-in digits grammars, especially with VXML applications. If you continue to specify -di in a language, it will be ignored.
We have streamlined the Speech Engine such that its memory footprint has been reduced substantially. Under light loads, you should find that the Engine uses only about 150 MB of memory.
Be sure to note that if you upgrade to 9.1, you should download and install new license files following our new upgrade procedures that were put into place in 9.0.
Fixed a bug that caused loads to be improperly distributed when using multiple speech servers.

This is the first release of the LumenVox Continuous HMM Decoder for use with the Speech Engine. The Continuous model does not use compression, so it has higher resolution, resulting in increased accuracy. The continuous models have shown an accuracy increase across various domains, but at the expense of approximately 15-20% more processing time.
There are new noise reduction options available in 9.0, allowing better recognition in noisy environments.
The LumenVox Speech Engine version 9.0 offers improved support of the $GARBAGE rule, which allows grammars to be defined where utterances before and after the desired phrase can be ignored. This is programmatically challenging to do correctly, and this new version sets out to improve performance over previous mplementations of this rule.
The LumenVox License Server will no longer allow old licenses to work with the newer versions of the Speech Engine. This means that to use the latest versions of the software, you must ensure your software maintenance is up to date and download and install licenses with the newer maintenance date. For more information, see Upgrading LumenVox Software.

The release of 8.6.1000 should fix some longstanding problems with Asterisk lockup at startup.
New configuration files have been added to the Engine. This should allow greater control over Engine settings without having to use the API. A few older configuration files, such as the old license_client.conf, have been merged into these new files. If you still have the old configuration files in place, the Engine will prefer the values from those, so it should not break backwards compatibility for any users.
The Engine has a new startup procedure that should help catch problems earlier. There is a new startup procedure for the speech client (the SpeechPort interface) and a new startup procedure for the speech server.

Licenses can now be uninstalled, using the latest License Server. If you have a machine with licenses that were set up before the release of 8.5, you will need to upgrade those licenses. Users who do not need to uninstall a license should be unaffected by this change.
The location of files on Linux has been restructured. This represents a major revamp of the LumenVox software on Linux. Existing Linux users will need to take this into account when they upgrade. Note that we have also completely dropped the environment variables ($LVBIN, $LVLIB, etc.) on our Linux installationsPlease see Linux Directory Structure for information about where our files are now installed.
As part of this change, we have split the Engine into three separate Linux packages: an Engine client package, an Engine server package, and a "core" package containing files shared across all products. See upgrading the software for information on how to upgrade from 8.0.
Short words (e.g. "back" or "stop") should now have higher confidence scores when correctly recognized.

Improved the Engine's performance in a number of ways, particularly relating to memory use on Linux. Fixed some potential memory leaks.