---
title: AudioContext.createDelay()
slug: Web/API/BaseAudioContext/createDelay
translation_of: Web/API/BaseAudioContext/createDelay
original_slug: Web/API/AudioContext/createDelay
---
<p>{{ APIRef("Web Audio API") }}</p>

<div>
<p>  <code>createDelay() 是 </code> {{ domxref("AudioContext") }}   的一个方法，作用是将输入音频信号延迟一定时间。（比如可以实现 对着话筒说句话，然后几秒后 这句话从音响里播放出来）</p>

<p> </p>
</div>

<h2 id="语法">语法</h2>

<pre class="brush: js">var audioCtx = new AudioContext();
var synthDelay = audioCtx.createDelay(<em>maxDelayTime</em>);</pre>

<h3 id="参数">参数</h3>

<dl>
 <dt><em>maxDelayTime</em></dt>
 <dd>设置最大允许延迟的时间，以“秒”为单位</dd>
</dl>

<h3 id="返回">返回</h3>

<p>A {{domxref("DelayNode")}}. The default {{domxref("DelayNode.delayTime")}} if no parameter is passed to <code>createDelay()</code> is 0 seconds.</p>

<p>以上是原文，大意是返回延时时间，没有设置时默认是0</p>

<p> </p>

<h2 id="示例">示例</h2>

<p>首先是中文版的简洁的示例，这个例子中 话筒里接收到的声音 会延迟3秒 从音响中播放</p>

<pre>window.AudioContext = window.AudioContext || window.webkitAudioContext || window.mozAudioContext || window.msAudioContext;

<code>try {//音频相关api
    var audioContext = new window.AudioContext();
</code>    var synthDelay = <code>audioContext</code>.createDelay(5.0);
<code>} catch (e) {
    alert("你浏览器不支持");
}


var error = function (error) {alert("有错误"); };

//以下是获取麦克风
if (navigator.getUserMedia) { //标准api
 navigator.getUserMedia({ "audio": true },
 function (stream) {
 micto(stream);    //具体工作
                   }, error);
}else if(navigator.webkitGetUserMedia) {   //webkit api
 navigator.webkitGetUserMedia({audio:true, video:  false },
 function (stream) {
  micto(stream); //具体工作
                   }, error);
 }else if (navigator.mozGetUserMedia) {  //火狐 api
 navigator.mozGetUserMedia({ "audio": true },
 function (stream) {
  micto(stream);//具体工作
                   }, error);
 }else if (navigator.msGetUserMedia) { //ie api
 navigator.msGetUserMedia({ "audio": true },
 function (stream) {
  micto(stream);//具体工作
                   }, error);
 } else {
   alert("您的浏览器版不支持这个api");
}





 var micto = function(stream) {

  synthDelay.delayTime.value = 3.0;   //延迟3秒

  var source = audioContext.createMediaStreamSource(stream);

  source.connect(synthDelay);

  synthDelay.connect(audioContext.destination);

      }
 </code></pre>

<p> </p>

<p> 以下是英文版示例</p>

<p>We have created a simple example that allows you to play three different samples on a constant loop — see <a href="http://chrisdavidmills.github.io/create-delay/">create-delay</a> (you can also <a href="https://github.com/chrisdavidmills/create-delay">view the source code</a>). If you just press the play buttons, the loops will start immediately; if you slide the sliders up to the right, then press the play buttons, a delay will be introduced, so the looping sounds don't start playing for a short amount of time.</p>

<pre class="brush: js;highlight[4,15,16,21,22]">var AudioContext = window.AudioContext || window.webkitAudioContext;
var audioCtx = new AudioContext();

var synthDelay = audioCtx.createDelay(5.0);

  ...

var synthSource;

playSynth.onclick = function() {
  synthSource = audioCtx.createBufferSource();
  synthSource.buffer = buffers[2];
  synthSource.loop = true;
  synthSource.start();
  synthSource.connect(synthDelay);
  synthDelay.connect(destination);
  this.setAttribute('disabled', 'disabled');
}

stopSynth.onclick = function() {
  synthSource.disconnect(synthDelay);
  synthDelay.disconnect(destination);
  synthSource.stop();
  playSynth.removeAttribute('disabled');
}

...

var delay1;
rangeSynth.oninput = function() {
delay1 = rangeSynth.value;
synthDelay.delayTime.value = delay1;
}
</pre>

<h2 id="Specifications">Specifications</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
  <tr>
   <td>{{SpecName('Web Audio API', '#widl-AudioContext-createDelay-DelayNode-double-maxDelayTime', 'createDelay()')}}</td>
   <td>{{Spec2('Web Audio API')}}</td>
   <td> </td>
  </tr>
 </tbody>
</table>

<h2 id="Browser_compatibility">Browser compatibility</h2>

<div>{{CompatibilityTable}}</div>

<div id="compat-desktop">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Chrome</th>
   <th>Edge</th>
   <th>Firefox (Gecko)</th>
   <th>Internet Explorer</th>
   <th>Opera</th>
   <th>Safari (WebKit)</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>{{CompatChrome(10.0)}}{{property_prefix("webkit")}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatGeckoDesktop(25.0)}} </td>
   <td>{{CompatNo}}</td>
   <td>15.0{{property_prefix("webkit")}}<br>
    22 (unprefixed)</td>
   <td>6.0{{property_prefix("webkit")}}</td>
  </tr>
 </tbody>
</table>
</div>

<div id="compat-mobile">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Android</th>
   <th>Edge</th>
   <th>Firefox Mobile (Gecko)</th>
   <th>Firefox OS</th>
   <th>IE Mobile</th>
   <th>Opera Mobile</th>
   <th>Safari Mobile</th>
   <th>Chrome for Android</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>26.0</td>
   <td>1.2</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>33.0</td>
  </tr>
 </tbody>
</table>
</div>

<h2 id="See_also">See also</h2>

<ul>
 <li><a href="/en-US/docs/Web_Audio_API/Using_Web_Audio_API">Using the Web Audio API</a></li>
</ul>