Silverlight Speech Recognition (In browser)

Question

Since this topic is a bit out dated I would like to re-discuss it here.

After searching the web, I came across the following link:

http://archive.msdn.microsoft.com/nesl which runs only out of browser because Silverlight (in browser) can't access certain COM libraries that are related to windows.

I wish (for obvious performance purposes) to perform the speech recognition through Silverlight (on the client machine) and then send the result (text) to the server via a postback to perform the corresponding action.

I already achieved a way to get the voice from the microphone and store it in Silverlight in a byte array. Is there a way to convert the speech byte array to text?

HTML5 Google service is not an acceptable approach since IE is required.

My final goal is to implement a speech recognition in ASP.NET Web Application.

Any suggestion is appreciated.

Answer 1

You can't do it in Silverlight. You'll need to send the audio somewhere. You can call some third-party service (I'm sure there are plenty--and it shouldn't matter that you're using IE) or your own ASP.NET (which can call System.Speech or any other free or commercial system). But before you do that, you should compress the audio. There aren't a lot of options in Silverlight. I recommend NSpeex, or at least convert it to 16kHz PCM (either linear or a-law).

Here's a list of Speech SDKs (many of which have a cloud service component): http://www.toolsjournal.com/mobile-articles/item/918-top-10-sdks-to-voice-enable-mobile-apps-quickly

Answer 2

To make Trusted In-browser Silverlight application:

http://msdn.microsoft.com/en-us/library/gg192793(v=vs.95).aspx

http://www.pitorque.de/MisterGoodcat/post/Silverlight-5-Tidbits-Trusted-applications.aspx

And for security background:

http://msdn.microsoft.com/en-us/library/ee721083%28v=vs.95%29.aspx

Note that NESL doesn't support DictionaryGrammar. Grammar needs to be pre-defined:

http://archive.msdn.microsoft.com/nesl/Thread/View.aspx?ThreadId=4905