SpeechRecognitionEngine.InitialSilenceTimeout 属性
定义
重要
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获取或设置时间间隔，在此时间间隔内，SpeechRecognitionEngine 将在终结识别之前接受仅包含无声段的输入。
public:
property TimeSpan InitialSilenceTimeout { TimeSpan get(); void set(TimeSpan value); };public TimeSpan InitialSilenceTimeout { get; set; }member this.InitialSilenceTimeout : TimeSpan with get, setPublic Property InitialSilenceTimeout As TimeSpan属性值
安静间隔的持续时间。
例外
该属性已设置为小于 0 秒。
示例
以下示例演示演示基本语音识别的控制台应用程序的一部分。 该示例在启动语音识别之前设置 BabbleTimeout 的 SpeechRecognitionEngine 和 InitialSilenceTimeout 属性。 语音识别器和AudioStateChangedRecognizeCompleted事件的处理程序将事件信息输出到控制台，以演示属性的属性SpeechRecognitionEngine如何影响InitialSilenceTimeout识别操作。
using System;
using System.Speech.Recognition;
namespace SpeechRecognitionApp
{
class Program
{
static void Main(string[] args)
{
// Initialize an in-process speech recognizer.
using (SpeechRecognitionEngine recognizer =
new SpeechRecognitionEngine(
new System.Globalization.CultureInfo("en-US")))
{
// Load a Grammar object.
recognizer.LoadGrammar(CreateServicesGrammar("FindServices"));
// Add event handlers.
recognizer.AudioStateChanged +=
new EventHandler<AudioStateChangedEventArgs>(
AudioStateChangedHandler);
recognizer.RecognizeCompleted +=
new EventHandler<RecognizeCompletedEventArgs>(
RecognizeCompletedHandler);
// Configure input to the speech recognizer.
recognizer.SetInputToDefaultAudioDevice();
recognizer.InitialSilenceTimeout = TimeSpan.FromSeconds(3);
recognizer.BabbleTimeout = TimeSpan.FromSeconds(2);
recognizer.EndSilenceTimeout = TimeSpan.FromSeconds(1);
recognizer.EndSilenceTimeoutAmbiguous = TimeSpan.FromSeconds(1.5);
Console.WriteLine("BabbleTimeout: {0}", recognizer.BabbleTimeout);
Console.WriteLine("InitialSilenceTimeout: {0}", recognizer.InitialSilenceTimeout);
Console.WriteLine("EndSilenceTimeout: {0}", recognizer.EndSilenceTimeout);
Console.WriteLine("EndSilenceTimeoutAmbiguous: {0}", recognizer.EndSilenceTimeoutAmbiguous);
Console.WriteLine();
// Start asynchronous speech recognition.
recognizer.RecognizeAsync(RecognizeMode.Single);
// Keep the console window open.
while (true)
{
Console.ReadLine();
}
}
}
// Create a grammar and build it into a Grammar object.
static Grammar CreateServicesGrammar(string grammarName)
{
// Create a grammar for finding services in different cities.
Choices services = new Choices(new string[] { "restaurants", "hotels", "gas stations" });
Choices cities = new Choices(new string[] { "Seattle", "Boston", "Dallas" });
GrammarBuilder findServices = new GrammarBuilder("Find");
findServices.Append(services);
findServices.Append("near");
findServices.Append(cities);
// Create a Grammar object from the GrammarBuilder.
Grammar servicesGrammar = new Grammar(findServices);
servicesGrammar.Name = ("FindServices");
return servicesGrammar;
}
// Handle the AudioStateChanged event.
static void AudioStateChangedHandler(
object sender, AudioStateChangedEventArgs e)
{
Console.WriteLine("AudioStateChanged ({0}): {1}",
DateTime.Now.ToString("mm:ss.f"), e.AudioState);
}
// Handle the RecognizeCompleted event.
static void RecognizeCompletedHandler(
object sender, RecognizeCompletedEventArgs e)
{
Console.WriteLine("RecognizeCompleted ({0}):",
DateTime.Now.ToString("mm:ss.f"));
string resultText;
if (e.Result != null) { resultText = e.Result.Text; }
else { resultText = "<null>"; }
Console.WriteLine(
" BabbleTimeout: {0}; InitialSilenceTimeout: {1}; Result text: {2}",
e.BabbleTimeout, e.InitialSilenceTimeout, resultText);
if (e.Error != null)
{
Console.WriteLine(" Exception message: ", e.Error.Message);
}
// Start the next asynchronous recognition operation.
((SpeechRecognitionEngine)sender).RecognizeAsync(RecognizeMode.Single);
}
}
}
注解
每个语音识别器都有一种算法来区分沉默和语音。 如果识别器输入在初始静音超时期间处于静音状态，则识别器将完成该识别操作。
对于异步识别操作和仿真，识别器将 RecognizeCompleted 引发 事件，其中 RecognizeCompletedEventArgs.InitialSilenceTimeout 属性为
true， RecognizeCompletedEventArgs.Result 属性为null。对于同步识别操作和仿真，识别器返回
null，而不是有效的 RecognitionResult。
如果初始静音超时间隔设置为 0，则识别器不会检查执行初始静音超时。 超时间隔可以是任何非负值。 默认值为 0 秒。
