Revision 930547 of GainNode

<p>{{ APIRef("Web Audio API") }}</p>

<div>
<p>The <code>GainNode</code> interface represents a change in volume. It is an {{domxref("AudioNode")}} audio-processing module that causes a given gain to be applied to the input data before its propagation to the output. A <code>GainNode</code> always has exactly one input and one output, both with the same number of channels.</p>
</div>

<p>The gain is a unitless value, changing with time, that is multiplied to each corresponding sample of all input channels. If modified, the new gain is applied using a de-zippering algorithm in order to prevent unaesthetic 'clicks' from appearing in the resulting audio.</p>

<p><img alt="The GainNode is increasing the gain of the output." src="https://mdn.mozillademos.org/files/5085/WebAudioGainNode.png" style="height:116px; width:774px" /></p>

<table class="properties">
 <tbody>
  <tr>
   <th scope="row">Number of inputs</th>
   <td><code>1</code></td>
  </tr>
  <tr>
   <th scope="row">Number of outputs</th>
   <td><code>1</code></td>
  </tr>
  <tr>
   <th scope="row">Channel count mode</th>
   <td><code>"max"</code></td>
  </tr>
  <tr>
   <th scope="row">Channel count</th>
   <td><code>2</code> (not used in the default count mode)</td>
  </tr>
  <tr>
   <th scope="row">Channel interpretation</th>
   <td><code>"speakers"</code></td>
  </tr>
 </tbody>
</table>

<h2 id="Properties">Properties</h2>

<p><em>Inherits properties from its parent, </em><em>{{domxref("AudioNode")}}</em>.</p>

<dl>
 <dt>{{domxref("GainNode.gain")}} {{readonlyinline}}</dt>
 <dd>Is an {{a-rate}} {{domxref("AudioParam")}} representing the amount of gain to apply.</dd>
</dl>

<h2 id="Methods">Methods</h2>

<p><em>No specific method; inherits methods from its parent, </em><em>{{domxref("AudioNode")}}</em>.</p>

<h2 id="Example">Example</h2>

<p>{{page("/en-US/docs/Web/API/AudioContext.createGain","Example")}}</p>

<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', '#the-gainnode-interface', 'GainNode')}}</td>
   <td>{{Spec2('Web Audio API')}}</td>
   <td>&nbsp;</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>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>{{CompatGeckoDesktop(25.0)}}&nbsp;</td>
   <td>{{CompatNo}}</td>
   <td>15.0{{property_prefix("webkit")}}<br />
    22</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>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>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>