diff --git a/dom/base/nsGkAtomList.h b/dom/base/nsGkAtomList.h
index 58014713432c..1558cdc6e0be 100644
--- a/dom/base/nsGkAtomList.h
+++ b/dom/base/nsGkAtomList.h
@@ -627,7 +627,6 @@ GK_ATOM(mouseout, "mouseout")
 GK_ATOM(mouseover, "mouseover")
 GK_ATOM(mousethrough, "mousethrough")
 GK_ATOM(mouseup, "mouseup")
-GK_ATOM(mozaudiochannel, "mozaudiochannel")
 GK_ATOM(mozfullscreenchange, "mozfullscreenchange")
 GK_ATOM(mozfullscreenerror, "mozfullscreenerror")
 GK_ATOM(mozpointerlockchange, "mozpointerlockchange")
@@ -1959,10 +1958,6 @@ GK_ATOM(onuserproximity, "onuserproximity")
 // light sensor support
 GK_ATOM(ondevicelight, "ondevicelight")
 
-// Audio channel events
-GK_ATOM(onmozinterruptbegin, "onmozinterruptbegin")
-GK_ATOM(onmozinterruptend, "onmozinterruptend")
-
 // MediaDevices device change event
 GK_ATOM(ondevicechange, "ondevicechange")
 
diff --git a/dom/html/HTMLMediaElement.cpp b/dom/html/HTMLMediaElement.cpp
index cd8e05bbdd76..1fa3f427b850 100644
--- a/dom/html/HTMLMediaElement.cpp
+++ b/dom/html/HTMLMediaElement.cpp
@@ -1444,23 +1444,6 @@ NS_IMPL_BOOL_ATTR(HTMLMediaElement, Loop, loop)
 NS_IMPL_BOOL_ATTR(HTMLMediaElement, DefaultMuted, muted)
 NS_IMPL_ENUM_ATTR_DEFAULT_VALUE(HTMLMediaElement, Preload, preload, nullptr)
 
-NS_IMETHODIMP
-HTMLMediaElement::GetMozAudioChannelType(nsAString& aValue)
-{
-  nsString defaultValue;
-  AudioChannelService::GetDefaultAudioChannelString(defaultValue);
-
-  NS_ConvertUTF16toUTF8 str(defaultValue);
-  GetEnumAttr(nsGkAtoms::mozaudiochannel, str.get(), aValue);
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-HTMLMediaElement::SetMozAudioChannelType(const nsAString& aValue)
-{
-  return SetAttrHelper(nsGkAtoms::mozaudiochannel, aValue);
-}
-
 NS_IMETHODIMP_(bool)
 HTMLMediaElement::IsVideo()
 {
@@ -4142,77 +4125,12 @@ bool HTMLMediaElement::ParseAttribute(int32_t aNamespaceID,
     if (aAttribute == nsGkAtoms::preload) {
       return aResult.ParseEnumValue(aValue, kPreloadTable, false);
     }
-
-    // Remove the b2g-specific audio channel setting in bug1299390.
-    if (aAttribute == nsGkAtoms::mozaudiochannel) {
-      const nsAttrValue::EnumTable* table =
-        AudioChannelService::GetAudioChannelTable();
-      MOZ_ASSERT(table);
-
-      bool parsed = aResult.ParseEnumValue(aValue, table, false, &table[0]);
-      if (!parsed) {
-        return false;
-      }
-
-      AudioChannel audioChannel = static_cast<AudioChannel>(aResult.GetEnumValue());
-
-      if (audioChannel == mAudioChannel ||
-          !CheckAudioChannelPermissions(aValue)) {
-        return true;
-      }
-
-      // We cannot change the AudioChannel of a decoder.
-      if (mDecoder) {
-        return true;
-      }
-
-      mAudioChannel = audioChannel;
-
-      if (mSrcStream) {
-        RefPtr<MediaStream> stream = GetSrcMediaStream();
-        if (stream) {
-          stream->SetAudioChannelType(mAudioChannel);
-        }
-      }
-
-      return true;
-    }
   }
 
   return nsGenericHTMLElement::ParseAttribute(aNamespaceID, aAttribute, aValue,
                                               aResult);
 }
 
-bool HTMLMediaElement::CheckAudioChannelPermissions(const nsAString& aString)
-{
-  // Only normal channel doesn't need permission.
-  if (aString.EqualsASCII("normal")) {
-    return true;
-  }
-
-  // Maybe this audio channel is equal to the default value from the pref.
-  nsString audioChannel;
-  AudioChannelService::GetDefaultAudioChannelString(audioChannel);
-  if (audioChannel.Equals(aString)) {
-    return true;
-  }
-
-  nsCOMPtr<nsIPermissionManager> permissionManager =
-    services::GetPermissionManager();
-  if (!permissionManager) {
-    return false;
-  }
-
-  uint32_t perm = nsIPermissionManager::UNKNOWN_ACTION;
-  permissionManager->TestExactPermissionFromPrincipal(NodePrincipal(),
-    nsCString(NS_LITERAL_CSTRING("audio-channel-") + NS_ConvertUTF16toUTF8(aString)).get(), &perm);
-  if (perm != nsIPermissionManager::ALLOW_ACTION) {
-    return false;
-  }
-
-  return true;
-}
-
 void HTMLMediaElement::DoneCreatingElement()
 {
    if (HasAttr(kNameSpaceID_None, nsGkAtoms::muted)) {
@@ -7063,15 +6981,6 @@ HTMLMediaElement::GetOrCreateTextTrackManager()
   return mTextTrackManager;
 }
 
-void
-HTMLMediaElement::SetMozAudioChannelType(AudioChannel aValue, ErrorResult& aRv)
-{
-  nsString channel;
-  channel.AssignASCII(AudioChannelValues::strings[uint32_t(aValue)].value,
-                      AudioChannelValues::strings[uint32_t(aValue)].length);
-  SetHTMLAttr(nsGkAtoms::mozaudiochannel, channel, aRv);
-}
-
 MediaDecoderOwner::NextFrameStatus
 HTMLMediaElement::NextFrameStatus()
 {
diff --git a/dom/html/HTMLMediaElement.h b/dom/html/HTMLMediaElement.h
index c5f9f382e9de..539b6ab311aa 100644
--- a/dom/html/HTMLMediaElement.h
+++ b/dom/html/HTMLMediaElement.h
@@ -693,13 +693,6 @@ public:
 
   double MozFragmentEnd();
 
-  AudioChannel MozAudioChannelType() const
-  {
-    return mAudioChannel;
-  }
-
-  void SetMozAudioChannelType(AudioChannel aValue, ErrorResult& aRv);
-
   AudioTrackList* AudioTracks();
 
   VideoTrackList* VideoTracks();
@@ -751,9 +744,6 @@ public:
   // that will soon be gone.
   bool IsBeingDestroyed();
 
-  IMPL_EVENT_HANDLER(mozinterruptbegin)
-  IMPL_EVENT_HANDLER(mozinterruptend)
-
   // These are used for testing only
   float ComputedVolume() const;
   bool ComputedMuted() const;
@@ -1250,9 +1240,6 @@ protected:
 
   void ReportTelemetry();
 
-  // Check the permissions for audiochannel.
-  bool CheckAudioChannelPermissions(const nsAString& aType);
-
   // Seeks to aTime seconds. aSeekType can be Exact to seek to exactly the
   // seek target, or PrevSyncPoint if a quicker but less precise seek is
   // desired, and we'll seek to the sync point (keyframe and/or start of the
diff --git a/dom/html/test/file_mozaudiochannel.html b/dom/html/test/file_mozaudiochannel.html
deleted file mode 100644
index 588ae338ba9b..000000000000
--- a/dom/html/test/file_mozaudiochannel.html
+++ /dev/null
@@ -1,91 +0,0 @@
-<!DOCTYPE HTML>
-<html>
-<body>
-<div id="content" style="display: none">
-  <audio id="audio1" />
-  <audio id="audio2" mozaudiochannel="foo" />
-</div>
-
-<script type="application/javascript">
-
-function is(a, b, msg) {
-  parent.postMessage({ status: a === b, msg: msg }, '*');
-}
-
-function ok(a, msg) {
-  parent.postMessage({ status: !!a, msg: msg }, '*');
-}
-
-function finish() {
-  parent.postMessage({ finish: true }, '*');
-}
-
-function test_basic() {
-  var audio1 = document.getElementById("audio1");
-  ok(audio1, "Audio Element exists");
-  is(audio1.mozAudioChannelType, "normal", "Default audio1 channel == 'normal'");
-  try {
-  audio1.mozAudioChannelType = "foo";
-  } catch(e) {}
-  is(audio1.mozAudioChannelType, "normal", "Default audio1 channel == 'normal'");
-
-  var audio2 = document.getElementById("audio2");
-  ok(audio2, "Audio Element exists");
-  is(audio2.mozAudioChannelType, "normal", "Default audio2 channel == 'normal'");
-  try {
-  audio2.mozAudioChannelType = "foo";
-  } catch(e) {}
-  is(audio2.mozAudioChannelType, "normal", "Default audio2 channel == 'normal'");
-
-  runTest();
-}
-
-function test_preferences(aChannel) {
-  SpecialPowers.pushPrefEnv({"set": [["media.defaultAudioChannel", aChannel ]]},
-    function() {
-      var audio = document.createElement('audio');
-      ok(audio, "Audio Element created");
-      is(audio.mozAudioChannelType, aChannel, "Default audio channel == '" + aChannel + "'");
-      runTest();
-    }
-  );
-}
-
-function test_wrong_preferences() {
-  SpecialPowers.pushPrefEnv({"set": [["media.defaultAudioChannel", 'foobar' ]]},
-    function() {
-      var audio = document.createElement('audio');
-      ok(audio, "Audio Element created");
-      is(audio.mozAudioChannelType, 'normal', "Default audio channel == 'normal'");
-      runTest();
-    }
-  );
-}
-var tests = [
-  test_basic,
-
-  function() { test_preferences("content"); },
-  function() { test_preferences("notification"); },
-  function() { test_preferences("alarm"); },
-  function() { test_preferences("telephony"); },
-  function() { test_preferences("ringer"); },
-  function() { test_preferences("publicnotification"); },
-
-  test_wrong_preferences,
-];
-
-function runTest() {
-  if (!tests.length) {
-    finish();
-    return;
-  }
-
-  var test = tests.shift();
-  test();
-}
-
-runTest();
-
-</script>
-</body>
-</html>
diff --git a/dom/html/test/mochitest.ini b/dom/html/test/mochitest.ini
index b0870b14e2db..78cb54779b12 100644
--- a/dom/html/test/mochitest.ini
+++ b/dom/html/test/mochitest.ini
@@ -183,7 +183,6 @@ support-files =
   reflect.js
   file_ignoreuserfocus.html
   simpleFileOpener.js
-  file_mozaudiochannel.html
   file_bug1166138_1x.png
   file_bug1166138_2x.png
   file_bug1166138_def.png
@@ -506,7 +505,6 @@ skip-if = toolkit == 'android' # bug 939642
 [test_map_attributes_reflection.html]
 [test_meta_attributes_reflection.html]
 [test_mod_attributes_reflection.html]
-[test_mozaudiochannel.html]
 [test_named_options.html]
 [test_nested_invalid_fieldsets.html]
 [test_object_attributes_reflection.html]
diff --git a/dom/html/test/test_mozaudiochannel.html b/dom/html/test/test_mozaudiochannel.html
deleted file mode 100644
index 722e181bf154..000000000000
--- a/dom/html/test/test_mozaudiochannel.html
+++ /dev/null
@@ -1,31 +0,0 @@
-<!DOCTYPE HTML>
-<html>
-<head>
-  <title>Test for mozaudiochannel</title>
-  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
-  <script type="text/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
-  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
-</head>
-<body>
-
-<pre id="test">
-<script type="application/javascript">
-
-SimpleTest.waitForExplicitFinish();
-SpecialPowers.pushPrefEnv({"set": [["media.useAudioChannelAPI", true]]}, function() {
-  var ifr = document.createElement('iframe');
-  ifr.src = 'file_mozaudiochannel.html';
-  onmessage = function(e) {
-    if ("finish" in e.data) {
-      SimpleTest.finish();
-    } else {
-      ok(e.data.status, e.data.msg);
-    }
-  }
-
-  document.body.appendChild(ifr);
-});
-</script>
-</pre>
-</body>
-</html>
diff --git a/dom/interfaces/html/nsIDOMHTMLMediaElement.idl b/dom/interfaces/html/nsIDOMHTMLMediaElement.idl
index 7a03320794c9..0cadc614aeea 100644
--- a/dom/interfaces/html/nsIDOMHTMLMediaElement.idl
+++ b/dom/interfaces/html/nsIDOMHTMLMediaElement.idl
@@ -87,40 +87,6 @@ interface nsIDOMHTMLMediaElement : nsISupports
   // it is equal to the media duration.
   readonly attribute double mozFragmentEnd;
 
-   // Mozilla extension: an audio channel type for media elements.
-   // An exception is thrown if the app tries to change the audio channel type
-   // without the permission (manifest file for B2G apps).
-   // The supported values are:
-   // * normal (default value)
-   //   Automatically paused if "notification" or higher priority channel
-   //   is played
-   //   Use case: normal applications
-   // * content
-   //   Automatically paused if "notification" or higher priority channel
-   //   is played. Also paused if another app starts using "content"
-   //   channel. Using this channel never affects applications using
-   //   the "normal" channel.
-   //   Use case: video/audio players
-   // * notification
-   //   Automatically paused if "alarm" or higher priority channel is played.
-   //   Use case: New email, incoming SMS
-   // * alarm
-   //   Automatically paused if "telephony" or higher priority channel is
-   //   played.
-   //   User case: Alarm clock, calendar alarms
-   // * telephony
-   //   Automatically paused if "ringer" or higher priority
-   //   channel is played.
-   //   Use case: dialer, voip
-   // * ringer
-   //   Automatically paused if "publicnotification" or higher priority
-   //   channel is played.
-   //   Use case: dialer, voip
-   // * publicnotification
-   //   Always plays in speaker, even when headphones are plugged in.
-   //   Use case: Camera shutter sound.
-   attribute DOMString mozAudioChannelType;
-
   // In addition the media element has this new events:
   // * onmozinterruptbegin - called when the media element is interrupted
   //   because of the audiochannel manager.
diff --git a/dom/media/webaudio/AudioContext.cpp b/dom/media/webaudio/AudioContext.cpp
index 01f886400ea7..31a825f257f1 100644
--- a/dom/media/webaudio/AudioContext.cpp
+++ b/dom/media/webaudio/AudioContext.cpp
@@ -1066,21 +1066,6 @@ AudioContext::Unmute() const
   }
 }
 
-AudioChannel
-AudioContext::MozAudioChannelType() const
-{
-  return mDestination->MozAudioChannelType();
-}
-
-AudioChannel
-AudioContext::TestAudioChannelInAudioNodeStream()
-{
-  MediaStream* stream = mDestination->Stream();
-  MOZ_ASSERT(stream);
-
-  return stream->AudioChannelType();
-}
-
 size_t
 AudioContext::SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
 {
diff --git a/dom/media/webaudio/AudioContext.h b/dom/media/webaudio/AudioContext.h
index 7cfd71f2b371..64d2e3577905 100644
--- a/dom/media/webaudio/AudioContext.h
+++ b/dom/media/webaudio/AudioContext.h
@@ -312,10 +312,6 @@ public:
 
   JSObject* GetGlobalJSObject() const;
 
-  AudioChannel MozAudioChannelType() const;
-
-  AudioChannel TestAudioChannelInAudioNodeStream();
-
   void RegisterNode(AudioNode* aNode);
   void UnregisterNode(AudioNode* aNode);
 
@@ -323,9 +319,6 @@ public:
 
   BasicWaveFormCache* GetBasicWaveFormCache();
 
-  IMPL_EVENT_HANDLER(mozinterruptbegin)
-  IMPL_EVENT_HANDLER(mozinterruptend)
-
   bool CheckClosed(ErrorResult& aRv);
 
   void Dispatch(already_AddRefed<nsIRunnable>&& aRunnable);
diff --git a/dom/media/webaudio/AudioDestinationNode.cpp b/dom/media/webaudio/AudioDestinationNode.cpp
index 98618506994a..abe357e3264e 100644
--- a/dom/media/webaudio/AudioDestinationNode.cpp
+++ b/dom/media/webaudio/AudioDestinationNode.cpp
@@ -545,9 +545,6 @@ AudioDestinationNode::WindowSuspendChanged(nsSuspendedTypes aSuspend)
           "this = %p, aSuspend = %s\n", this, SuspendTypeToStr(aSuspend)));
 
   mAudioChannelSuspended = suspended;
-  Context()->DispatchTrustedEvent(!suspended ?
-    NS_LITERAL_STRING("mozinterruptend") :
-    NS_LITERAL_STRING("mozinterruptbegin"));
 
   DisabledTrackMode disabledMode = suspended ? DisabledTrackMode::SILENCE_BLACK
                                              : DisabledTrackMode::ENABLED;
diff --git a/dom/media/webaudio/test/mochitest.ini b/dom/media/webaudio/test/mochitest.ini
index 4345d79cfead..56a07ed0801a 100644
--- a/dom/media/webaudio/test/mochitest.ini
+++ b/dom/media/webaudio/test/mochitest.ini
@@ -171,9 +171,6 @@ tags=capturestream
 tags=capturestream
 [test_mixingRules.html]
 skip-if = toolkit == 'android' # bug 1091965
-[test_mozaudiochannel.html]
-# Android: bug 1061675; OSX 10.6: bug 1097721
-skip-if = (toolkit == 'android') || (os == 'mac' && os_version == '10.6')
 [test_nodeToParamConnection.html]
 [test_nodeCreationDocumentGone.html]
 [test_OfflineAudioContext.html]
diff --git a/dom/media/webaudio/test/test_mozaudiochannel.html b/dom/media/webaudio/test/test_mozaudiochannel.html
deleted file mode 100644
index 6ba14347bf70..000000000000
--- a/dom/media/webaudio/test/test_mozaudiochannel.html
+++ /dev/null
@@ -1,151 +0,0 @@
-<!DOCTYPE HTML>
-<html>
-<head>
-  <title>Test for mozaudiochannel</title>
-  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
-  <script type="text/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
-  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
-</head>
-<body>
-<p id="display"></p>
-<pre id="test">
-<script type="application/javascript">
-
-function test_basic() {
-  var ac = new AudioContext();
-  ok(ac, "AudioContext created");
-
-  // Default
-  is(ac.mozAudioChannelType, "normal", "Default ac channel == 'normal'");
-
-  // Unpermitted channels
-  ac = new AudioContext("content");
-  is(ac.mozAudioChannelType, "normal", "Default ac channel == 'normal'");
-
-  ac = new AudioContext("notification");
-  is(ac.mozAudioChannelType, "normal", "Default ac channel == 'normal'");
-
-  ac = new AudioContext("alarm");
-  is(ac.mozAudioChannelType, "normal", "Default ac channel == 'normal'");
-
-  ac = new AudioContext("telephony");
-  is(ac.mozAudioChannelType, "normal", "Default ac channel == 'normal'");
-
-  ac = new AudioContext("ringer");
-  is(ac.mozAudioChannelType, "normal", "Default ac channel == 'normal'");
-
-  ac = new AudioContext("publicnotification");
-  is(ac.mozAudioChannelType, "normal", "Default ac channel == 'normal'");
-
-  runTest();
-}
-
-function test_permission(aChannel) {
-  var ac = new AudioContext();
-  ok(ac, "AudioContext created");
-
-  is(ac.mozAudioChannelType, "normal", "Default ac channel == 'normal'");
-
-  var channel = SpecialPowers.wrap(ac).testAudioChannelInAudioNodeStream();
-  is(channel, "normal", "AudioNodeStream is using the correct default audio channel.");
-
-  SpecialPowers.pushPermissions(
-    [{ "type": "audio-channel-" + aChannel, "allow": true, "context": document }],
-    function() {
-      var ac = new AudioContext(aChannel);
-      is(ac.mozAudioChannelType, aChannel, "Default ac channel == '" + aChannel + "'");
-
-      var channel = SpecialPowers.wrap(ac).testAudioChannelInAudioNodeStream();
-      is(channel, aChannel, "AudioNodeStream is using the correct new audio channel.");
-
-      runTest();
-    }
-  );
-}
-
-function test_preferences(aChannel) {
-  SpecialPowers.pushPrefEnv({"set": [["media.defaultAudioChannel", aChannel ]]},
-    function() {
-      SpecialPowers.pushPermissions(
-        [{ "type": "audio-channel-" + aChannel, "allow": false, "context": document }],
-        function() {
-          var ac = new AudioContext(aChannel);
-          ok(ac, "AudioContext created");
-          is(ac.mozAudioChannelType, aChannel, "Default ac channel == '" + aChannel + "'");
-
-          var channel = SpecialPowers.wrap(ac).testAudioChannelInAudioNodeStream();
-          is(channel, aChannel, "AudioNodeStream is using the correct audio channel.");
-
-          runTest();
-        }
-      );
-    }
-  );
-}
-
-function test_wrong_preferences() {
-  SpecialPowers.pushPrefEnv({"set": [["media.defaultAudioChannel", 'foobar' ]]},
-    function() {
-      var ac = new AudioContext();
-      ok(ac, "AudioContext created");
-      is(ac.mozAudioChannelType, 'normal', "Default ac channel == 'normal'");
-      runTest();
-    }
-  );
-}
-
-function test_testAudioChannelInAudioNodeStream() {
-  var ac = new AudioContext();
-  ok(ac, "AudioContext created");
-
-  var status = false;
-  try {
-    ac.testAudioChannelInAudioNodeStream();
-  } catch(e) {
-    status = true;
-  }
-
-  ok(status, "testAudioChannelInAudioNodeStream() should not exist in content.");
-  runTest();
-}
-
-var tests = [
-  test_basic,
-
-  function() { test_permission("content"); },
-  function() { test_permission("notification"); },
-  function() { test_permission("alarm"); },
-  function() { test_permission("telephony"); },
-  function() { test_permission("ringer"); },
-  function() { test_permission("publicnotification"); },
-
-  function() { test_preferences("content"); },
-  function() { test_preferences("notification"); },
-  function() { test_preferences("alarm"); },
-  function() { test_preferences("telephony"); },
-  function() { test_preferences("ringer"); },
-  function() { test_preferences("publicnotification"); },
-
-  test_wrong_preferences,
-
-  test_testAudioChannelInAudioNodeStream,
-];
-
-function runTest() {
-  if (!tests.length) {
-    SimpleTest.finish();
-    return;
-  }
-
-  var test = tests.shift();
-  test();
-}
-
-SpecialPowers.pushPrefEnv({"set": [["media.useAudioChannelAPI", true ]]}, runTest);
-SimpleTest.waitForExplicitFinish();
-SimpleTest.requestLongerTimeout(5);
-
-</script>
-</pre>
-</body>
-</html>
diff --git a/dom/webidl/AudioContext.webidl b/dom/webidl/AudioContext.webidl
index cf4bd2acf000..72e3aabb87da 100644
--- a/dom/webidl/AudioContext.webidl
+++ b/dom/webidl/AudioContext.webidl
@@ -33,23 +33,4 @@ interface AudioContext : BaseAudioContext {
 
     [NewObject, Throws]
     MediaStreamAudioDestinationNode createMediaStreamDestination();
-};
-
-// Mozilla extensions
-partial interface AudioContext {
-  // Read AudioChannel.webidl for more information about this attribute.
-  [Pref="media.useAudioChannelAPI"]
-  readonly attribute AudioChannel mozAudioChannelType;
-
-  // These 2 events are dispatched when the AudioContext object is muted by
-  // the AudioChannelService. It's call 'interrupt' because when this event is
-  // dispatched on a HTMLMediaElement, the audio stream is paused.
-  [Pref="media.useAudioChannelAPI"]
-  attribute EventHandler onmozinterruptbegin;
-
-  [Pref="media.useAudioChannelAPI"]
-  attribute EventHandler onmozinterruptend;
-
-  // This method is for test only.
-  [ChromeOnly] AudioChannel testAudioChannelInAudioNodeStream();
-};
+};
\ No newline at end of file
diff --git a/dom/webidl/HTMLMediaElement.webidl b/dom/webidl/HTMLMediaElement.webidl
index 056a8bb1608e..4de2d228953b 100644
--- a/dom/webidl/HTMLMediaElement.webidl
+++ b/dom/webidl/HTMLMediaElement.webidl
@@ -138,21 +138,6 @@ partial interface HTMLMediaElement {
   // the media element has a fragment URI for the currentSrc, otherwise
   // it is equal to the media duration.
   readonly attribute double mozFragmentEnd;
-
-  // Mozilla extension: an audio channel type for media elements.
-  // Read AudioChannel.webidl for more information about this attribute.
-  [SetterThrows, Pref="media.useAudioChannelAPI"]
-  attribute AudioChannel mozAudioChannelType;
-
-  // In addition the media element has this new events:
-  // * onmozinterruptbegin - called when the media element is interrupted
-  //   because of the audiochannel manager.
-  // * onmozinterruptend - called when the interruption is concluded
-  [Pref="media.useAudioChannelAPI"]
-  attribute EventHandler onmozinterruptbegin;
-
-  [Pref="media.useAudioChannelAPI"]
-  attribute EventHandler onmozinterruptend;
 };
 
 // Encrypted Media Extensions