--- a/content/media/webaudio/AudioContext.cpp
+++ b/content/media/webaudio/AudioContext.cpp
@@ -7,16 +7,17 @@
 #include "AudioContext.h"
 #include "nsContentUtils.h"
 #include "nsIDOMWindow.h"
 #include "mozilla/ErrorResult.h"
 #include "mozilla/dom/AudioContextBinding.h"
 #include "AudioDestinationNode.h"
 #include "AudioBufferSourceNode.h"
 #include "AudioBuffer.h"
+#include "GainNode.h"
 
 namespace mozilla {
 namespace dom {
 
 NS_IMPL_CYCLE_COLLECTION_CLASS(AudioContext)
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_NATIVE(AudioContext)
   NS_IMPL_CYCLE_COLLECTION_UNLINK_NSCOMPTR(mWindow)
   NS_IMPL_CYCLE_COLLECTION_UNLINK_NSCOMPTR(mDestination)
@@ -81,11 +82,18 @@ AudioContext::CreateBuffer(JSContext* aJ
   nsRefPtr<AudioBuffer> buffer = new AudioBuffer(this, aLength, aSampleRate);
   if (!buffer->InitializeBuffers(aNumberOfChannels, aJSContext)) {
     aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
     return nullptr;
   }
   return buffer.forget();
 }
 
+already_AddRefed<GainNode>
+AudioContext::CreateGain()
+{
+  nsRefPtr<GainNode> gainNode = new GainNode(this);
+  return gainNode.forget();
+}
+
 }
 }
 

--- a/content/media/webaudio/AudioContext.h
+++ b/content/media/webaudio/AudioContext.h
@@ -21,16 +21,17 @@ namespace mozilla {
 
 class ErrorResult;
 
 namespace dom {
 
 class AudioDestinationNode;
 class AudioBufferSourceNode;
 class AudioBuffer;
+class GainNode;
 
 class AudioContext MOZ_FINAL : public nsWrapperCache,
                                public EnableWebAudioCheck
 {
   explicit AudioContext(nsIDOMWindow* aParentWindow);
 
 public:
   virtual ~AudioContext();
@@ -56,16 +57,19 @@ public:
 
   already_AddRefed<AudioBufferSourceNode> CreateBufferSource();
 
   already_AddRefed<AudioBuffer>
   CreateBuffer(JSContext* aJSContext, uint32_t aNumberOfChannels,
                uint32_t aLength, float aSampleRate,
                ErrorResult& aRv);
 
+  already_AddRefed<GainNode>
+  CreateGain();
+
 private:
   nsCOMPtr<nsIDOMWindow> mWindow;
   nsRefPtr<AudioDestinationNode> mDestination;
 };
 
 }
 }
 

new file mode 100644
--- /dev/null
+++ b/content/media/webaudio/GainNode.cpp
@@ -0,0 +1,42 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "GainNode.h"
+#include "mozilla/dom/GainNodeBinding.h"
+
+namespace mozilla {
+namespace dom {
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(GainNode)
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(GainNode, AudioNode)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK_NSCOMPTR(mGain)
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(GainNode, AudioNode)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NATIVE_PTR(tmp->mGain, AudioParam, "gain value")
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(GainNode)
+NS_INTERFACE_MAP_END_INHERITING(AudioNode)
+
+NS_IMPL_ADDREF_INHERITED(GainNode, AudioNode)
+NS_IMPL_RELEASE_INHERITED(GainNode, AudioNode)
+
+GainNode::GainNode(AudioContext* aContext)
+  : AudioNode(aContext)
+  , mGain(new AudioParam(aContext, 1.0f, 0.0f, 1.0f))
+{
+}
+
+JSObject*
+GainNode::WrapObject(JSContext* aCx, JSObject* aScope,
+                     bool* aTriedToWrap)
+{
+  return GainNodeBinding::Wrap(aCx, aScope, this, aTriedToWrap);
+}
+
+}
+}
+

new file mode 100644
--- /dev/null
+++ b/content/media/webaudio/GainNode.h
@@ -0,0 +1,51 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef GainNode_h_
+#define GainNode_h_
+
+#include "AudioNode.h"
+#include "AudioParam.h"
+
+namespace mozilla {
+namespace dom {
+
+class AudioContext;
+
+class GainNode : public AudioNode
+{
+public:
+  explicit GainNode(AudioContext* aContext);
+
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(GainNode, AudioNode)
+
+  virtual JSObject* WrapObject(JSContext* aCx, JSObject* aScope,
+                               bool* aTriedToWrap);
+
+  virtual uint32_t MaxNumberOfInputs() const MOZ_FINAL MOZ_OVERRIDE
+  {
+    return 1;
+  }
+  virtual uint32_t MaxNumberOfOutputs() const MOZ_FINAL MOZ_OVERRIDE
+  {
+    return 1;
+  }
+
+  AudioParam* Gain() const
+  {
+    return mGain;
+  }
+
+private:
+  nsRefPtr<AudioParam> mGain;
+};
+
+}
+}
+
+#endif
+

--- a/content/media/webaudio/Makefile.in
+++ b/content/media/webaudio/Makefile.in
@@ -18,26 +18,28 @@ CPPSRCS := \
   AudioBuffer.cpp \
   AudioBufferSourceNode.cpp \
   AudioContext.cpp \
   AudioDestinationNode.cpp \
   AudioNode.cpp \
   AudioParam.cpp \
   AudioSourceNode.cpp \
   EnableWebAudioCheck.cpp \
+  GainNode.cpp \
   $(NULL)
 
 EXPORTS_NAMESPACES := mozilla/dom
 EXPORTS_mozilla/dom := \
   AudioBuffer.h \
   AudioBufferSourceNode.h \
   AudioDestinationNode.h \
   AudioNode.h \
   AudioParam.h \
   AudioSourceNode.h \
+  GainNode.h \
   $(NULL)
 
 PARALLEL_DIRS := test
 
 ifdef ENABLE_TESTS
 TOOL_DIRS += compiledtest
 endif
 

--- a/content/media/webaudio/test/Makefile.in
+++ b/content/media/webaudio/test/Makefile.in
@@ -9,12 +9,13 @@ VPATH          := @srcdir@
 relativesrcdir := @relativesrcdir@
 
 include $(DEPTH)/config/autoconf.mk
 
 MOCHITEST_FILES := \
   test_AudioBuffer.html \
   test_AudioContext.html \
   test_badConnect.html \
+  test_gainNode.html \
   test_singleSourceDest.html \
   $(NULL)
 
 include $(topsrcdir)/config/rules.mk

new file mode 100644
--- /dev/null
+++ b/content/media/webaudio/test/test_gainNode.html
@@ -0,0 +1,58 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test GainNode</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+<pre id="test">
+<script class="testbody" type="text/javascript">
+
+SimpleTest.waitForExplicitFinish();
+addLoadEvent(function() {
+  SpecialPowers.setBoolPref("media.webaudio.enabled", true);
+
+  var context = new mozAudioContext();
+  var buffer = context.createBuffer(1, 2048, 44100);
+  for (var i = 0; i < 2048; ++i) {
+    buffer.getChannelData(0)[i] = Math.sin(440 * 2 * Math.PI * i / 44100);
+  }
+
+  var destination = context.destination;
+
+  var source = context.createBufferSource();
+
+  var gain = context.createGain();
+
+  source.buffer = buffer;
+
+  source.connect(gain);
+  gain.connect(destination);
+
+  ok(gain.gain, "The audioparam member must exist");
+  is(gain.gain.value, 1.0, "Correct initial value");
+  is(gain.gain.defaultValue, 1.0, "Correct default value");
+  is(gain.gain.minValue, 0, "Correct min value");
+  is(gain.gain.maxValue, 1.0, "Correct max value");
+  gain.gain.value = 0.5;
+  is(gain.gain.value, 0.5, "Correct initial value");
+  is(gain.gain.defaultValue, 1.0, "Correct default value");
+  is(gain.gain.minValue, 0, "Correct min value");
+  is(gain.gain.maxValue, 1.0, "Correct max value");
+
+  source.start(0);
+  SimpleTest.executeSoon(function() {
+    source.stop(0);
+    source.disconnect();
+    gain.disconnect();
+
+    SpecialPowers.clearUserPref("media.webaudio.enabled");
+    SimpleTest.finish();
+  });
+});
+
+</script>
+</pre>
+</body>
+</html>

--- a/dom/bindings/Bindings.conf
+++ b/dom/bindings/Bindings.conf
@@ -197,16 +197,21 @@ DOMInterfaces = {
     'workers': True,
 },
 
 'FormData': [
 {
     'workers': True,
 }],
 
+'GainNode': [
+{
+    'resultNotAddRefed': [ 'gain' ],
+}],
+
 'HTMLCollection': [
 {
     'nativeType': 'nsIHTMLCollection',
     'resultNotAddRefed': [ 'item' ]
 }],
 
 'HTMLOptionsCollection': [
 {

--- a/dom/webidl/AudioContext.webidl
+++ b/dom/webidl/AudioContext.webidl
@@ -20,12 +20,15 @@ interface mozAudioContext {
 
     // [Creator, Throws]
     // AudioBuffer createBuffer(ArrayBuffer buffer, boolean mixToMono);
 
     // AudioNode creation 
     [Creator]
     AudioBufferSourceNode createBufferSource();
 
+    [Creator]
+    GainNode createGain();
+
 };
 
 typedef mozAudioContext AudioContext;
 

new file mode 100644
--- /dev/null
+++ b/dom/webidl/GainNode.webidl
@@ -0,0 +1,19 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * The origin of this IDL file is
+ * https://dvcs.w3.org/hg/audio/raw-file/tip/webaudio/specification.html
+ *
+ * Copyright © 2012 W3C® (MIT, ERCIM, Keio), All Rights Reserved. W3C
+ * liability, trademark and document use rules apply.
+ */
+
+[PrefControlled]
+interface GainNode : AudioNode {
+
+    readonly attribute AudioParam gain;
+
+};
+

--- a/dom/webidl/WebIDL.mk
+++ b/dom/webidl/WebIDL.mk
@@ -24,16 +24,17 @@ webidl_files = \
   DOMTokenList.webidl \
   DOMSettableTokenList.webidl \
   Function.webidl \
   EventHandler.webidl \
   EventListener.webidl \
   EventTarget.webidl \
   FileList.webidl \
   FileReaderSync.webidl \
+  GainNode.webidl \
   HTMLCollection.webidl \
   HTMLOptionsCollection.webidl \
   HTMLPropertiesCollection.webidl \
   ImageData.webidl \
   NodeList.webidl \
   PaintRequestList.webidl \
   Performance.webidl \
   PerformanceNavigation.webidl \