---
title: GainNode.gain
slug: Web/API/GainNode/gain
tags:
  - API
translation_of: Web/API/GainNode/gain
---
<p>{{ APIRef("Web Audio API") }}</p>

<div>
<p>{{ domxref("GainNode") }} 介面的 <code>gain</code> 屬性是 <a href="/en-US/docs/Web/API/AudioParam#a-rate">a-rate</a> {{domxref("AudioParam")}}，代表增益的數值。</p>
</div>

<h2 id="語法">語法</h2>

<pre class="brush: js">var audioCtx = new AudioContext();
var gainNode = audioCtx.createGain();
gainNode.gain.value = 0.5;
</pre>

<h3 id="傳回值">傳回值</h3>

<p>一個 {{domxref("AudioParam")}}.</p>

<div class="note">
<p><strong>註：</strong> 雖然傳回的 <code>AudioParam</code> 是唯讀的，但是它所代表的值可以更改。</p>
</div>

<h2 id="範例">範例</h2>

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

<h2 id="規格">規格</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-GainNode-gain', 'gain')}}</td>
   <td>{{Spec2('Web Audio API')}}</td>
   <td> </td>
  </tr>
 </tbody>
</table>

<h2 id="瀏覽器相容度">瀏覽器相容度</h2>

{{Compat("api.GainNode.gain")}}

<h2 id="參見">參見</h2>

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