Here are the steps for getting a bare-bones C# program up and running to recognize speech input from the microphone using SAPI 5.1.
Caveat: SAPI 5.1 does not work under a C# console application, due to the Automation API's dependence on Windows' Message Pump, so you have to create a Form-based application.
- Create a new C# Windows Application in Visual Studio 2005.
- In the Solution Explorer, right click on References under your project node, and select Add Reference....
- Click on the COM tab, select Microsoft Speech Object Library (verify it's version 5.0), and click OK.
- Double click Form1.cs, and add a TextBox control, set its Multiline behavior property to True, change the Name design property to "result_textBox", and resize the control on the Form to an appropriate size (this will be where the recognized text will be output).
- Change your Form1.cs code to the following:
using System.Windows.Forms;
using SpeechLib;
namespace SimpleSAPI
{
public partial class Form1 : Form
{
// whether to use the command and control grammar or the dictation grammar
bool commandAndControl = false;
ISpeechRecoContext recoContext;
ISpeechRecoGrammar grammar;
public Form1()
{
InitializeComponent();
}
protected override void OnLoad(System.EventArgs e)
{
/****** BEGIN: set up recognition context *****/
result_textBox.AppendText("Dictation mode\n");
// create the recognition context
recoContext = new SpeechLib.SpSharedRecoContext();
((SpSharedRecoContext)recoContext).Recognition +=
new _ISpeechRecoContextEvents_RecognitionEventHandler(RecoContext_Recognition);
/****** END: set up recognition context *****/
// set up the grammar
grammar = recoContext.CreateGrammar(0);
// set up the dictation grammar
grammar.DictationLoad("", SpeechLoadOption.SLOStatic);
grammar.DictationSetState(SpeechRuleState.SGDSInactive);
// load the command and control grammar
grammar.CmdLoadFromFile(@"grammar.xml", SpeechLoadOption.SLOStatic);
grammar.CmdSetRuleIdState(0, SpeechRuleState.SGDSInactive);
// activate one of the grammars if we don't want both at the same time
if (commandAndControl)
grammar.CmdSetRuleIdState(0, SpeechRuleState.SGDSActive);
else
grammar.DictationSetState(SpeechRuleState.SGDSActive);
}
protected override void OnClosing(System.ComponentModel.CancelEventArgs e)
{
recoContext.State = SpeechRecoContextState.SRCS_Disabled;
}
void RecoContext_Recognition(int StreamNumber, object StreamPosition,
SpeechRecognitionType RecognitionType, ISpeechRecoResult Result)
{
result_textBox.AppendText(Result.PhraseInfo.GetText(0, -1, true) + "\n");
}
}
}
Note that the dictation grammar and the command-and-control grammar can be both active at the same time within the same speech recognition context.
To use a command-and-control grammar, set
commandAndControl to true, and save the following file as grammar.xml in the same directory as the executable:
<GRAMMAR LANGID="409">
<RULE NAME="toplevel" TOPLEVEL="ACTIVE">
<L>
<P>selected</P>
<P>interface</P>
<P>default</P>
</L>
</RULE>
</GRAMMAR>
Note that the
LANGID should be set to 409, it appears that is the ID for English.
