--- a/dom/media/webaudio/AudioContext.cpp
+++ b/dom/media/webaudio/AudioContext.cpp
@@ -25,16 +25,17 @@
 #include "AudioStream.h"
 #include "BiquadFilterNode.h"
 #include "ChannelMergerNode.h"
 #include "ChannelSplitterNode.h"
 #include "ConvolverNode.h"
 #include "DelayNode.h"
 #include "DynamicsCompressorNode.h"
 #include "GainNode.h"
+#include "IIRFilterNode.h"
 #include "MediaElementAudioSourceNode.h"
 #include "MediaStreamAudioDestinationNode.h"
 #include "MediaStreamAudioSourceNode.h"
 #include "MediaStreamGraph.h"
 #include "nsContentUtils.h"
 #include "nsNetCID.h"
 #include "nsNetUtil.h"
 #include "nsPIDOMWindow.h"
@@ -504,16 +505,30 @@ AudioContext::CreateBiquadFilter(ErrorRe
     return nullptr;
   }
 
   RefPtr<BiquadFilterNode> filterNode =
     new BiquadFilterNode(this);
   return filterNode.forget();
 }
 
+already_AddRefed<IIRFilterNode>
+AudioContext::CreateIIRFilter(const mozilla::dom::binding_detail::AutoSequence<double>& aFeedforward,
+                              const mozilla::dom::binding_detail::AutoSequence<double>& aFeedback,
+                              mozilla::ErrorResult& aRv)
+{
+  if (CheckClosed(aRv)) {
+    return nullptr;
+  }
+
+  RefPtr<IIRFilterNode> filterNode =
+    new IIRFilterNode(this);
+  return filterNode.forget();
+}
+
 already_AddRefed<OscillatorNode>
 AudioContext::CreateOscillator(ErrorResult& aRv)
 {
   if (CheckClosed(aRv)) {
     return nullptr;
   }
 
   RefPtr<OscillatorNode> oscillatorNode =

--- a/dom/media/webaudio/AudioContext.h
+++ b/dom/media/webaudio/AudioContext.h
@@ -52,19 +52,20 @@ class AudioListener;
 class AudioNode;
 class BiquadFilterNode;
 class ChannelMergerNode;
 class ChannelSplitterNode;
 class ConvolverNode;
 class DelayNode;
 class DynamicsCompressorNode;
 class GainNode;
+class GlobalObject;
 class HTMLMediaElement;
+class IIRFilterNode;
 class MediaElementAudioSourceNode;
-class GlobalObject;
 class MediaStreamAudioDestinationNode;
 class MediaStreamAudioSourceNode;
 class OscillatorNode;
 class PannerNode;
 class ScriptProcessorNode;
 class StereoPannerNode;
 class WaveShaperNode;
 class PeriodicWave;
@@ -246,16 +247,21 @@ public:
   CreateChannelMerger(uint32_t aNumberOfInputs, ErrorResult& aRv);
 
   already_AddRefed<DynamicsCompressorNode>
   CreateDynamicsCompressor(ErrorResult& aRv);
 
   already_AddRefed<BiquadFilterNode>
   CreateBiquadFilter(ErrorResult& aRv);
 
+  already_AddRefed<IIRFilterNode>
+  CreateIIRFilter(const mozilla::dom::binding_detail::AutoSequence<double>& aFeedforward,
+                  const mozilla::dom::binding_detail::AutoSequence<double>& aFeedback,
+                  mozilla::ErrorResult& aRv);
+
   already_AddRefed<OscillatorNode>
   CreateOscillator(ErrorResult& aRv);
 
   already_AddRefed<PeriodicWave>
   CreatePeriodicWave(const Float32Array& aRealData, const Float32Array& aImagData,
                      const PeriodicWaveConstraints& aConstraints,
                      ErrorResult& aRv);
 

--- a/dom/media/webaudio/moz.build
+++ b/dom/media/webaudio/moz.build
@@ -51,16 +51,17 @@ EXPORTS.mozilla.dom += [
     'AudioProcessingEvent.h',
     'BiquadFilterNode.h',
     'ChannelMergerNode.h',
     'ChannelSplitterNode.h',
     'ConvolverNode.h',
     'DelayNode.h',
     'DynamicsCompressorNode.h',
     'GainNode.h',
+    'IIRFilterNode.h',
     'MediaElementAudioSourceNode.h',
     'MediaStreamAudioDestinationNode.h',
     'MediaStreamAudioSourceNode.h',
     'OfflineAudioCompletionEvent.h',
     'OscillatorNode.h',
     'PannerNode.h',
     'PeriodicWave.h',
     'ScriptProcessorNode.h',
@@ -87,16 +88,17 @@ UNIFIED_SOURCES += [
     'ChannelMergerNode.cpp',
     'ChannelSplitterNode.cpp',
     'ConvolverNode.cpp',
     'DelayBuffer.cpp',
     'DelayNode.cpp',
     'DynamicsCompressorNode.cpp',
     'FFTBlock.cpp',
     'GainNode.cpp',
+    'IIRFilterNode.cpp',
     'MediaBufferDecoder.cpp',
     'MediaElementAudioSourceNode.cpp',
     'MediaStreamAudioDestinationNode.cpp',
     'MediaStreamAudioSourceNode.cpp',
     'OfflineAudioCompletionEvent.cpp',
     'OscillatorNode.cpp',
     'PannerNode.cpp',
     'PeriodicWave.cpp',

--- a/dom/webidl/AudioContext.webidl
+++ b/dom/webidl/AudioContext.webidl
@@ -70,16 +70,18 @@ interface AudioContext : EventTarget {
     MediaStreamAudioSourceNode createMediaStreamSource(MediaStream mediaStream);
     [NewObject, Throws]
     GainNode createGain();
     [NewObject, Throws]
     DelayNode createDelay(optional double maxDelayTime = 1);
     [NewObject, Throws]
     BiquadFilterNode createBiquadFilter();
     [NewObject, Throws]
+    IIRFilterNode createIIRFilter(sequence<double> feedforward, sequence<double> feedback);
+    [NewObject, Throws]
     WaveShaperNode createWaveShaper();
     [NewObject, Throws]
     PannerNode createPanner();
     [NewObject, Throws]
     ConvolverNode createConvolver();
 
     [NewObject, Throws]
     ChannelSplitterNode createChannelSplitter(optional unsigned long numberOfOutputs = 6);

new file mode 100644
--- /dev/null
+++ b/dom/webidl/IIRFilterNode.webidl
@@ -0,0 +1,17 @@
+/* -*- 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://www.w3.org/TR/webaudio
+ *
+ * Copyright © 2016 W3C® (MIT, ERCIM, Keio), All Rights Reserved. W3C
+ * liability, trademark and document use rules apply.
+ */
+
+interface IIRFilterNode : AudioNode {
+    void getFrequencyResponse(Float32Array frequencyHz, Float32Array magResponse, Float32Array phaseResponse);
+};
+
+// Mozilla extension
+IIRFilterNode implements AudioNodePassThrough;

--- a/dom/webidl/moz.build
+++ b/dom/webidl/moz.build
@@ -260,16 +260,17 @@ WEBIDL_FILES = [
     'IDBIndex.webidl',
     'IDBKeyRange.webidl',
     'IDBMutableFile.webidl',
     'IDBObjectStore.webidl',
     'IDBOpenDBRequest.webidl',
     'IDBRequest.webidl',
     'IDBTransaction.webidl',
     'IDBVersionChangeEvent.webidl',
+    'IIRFilterNode.webidl',
     'ImageBitmap.webidl',
     'ImageBitmapRenderingContext.webidl',
     'ImageCapture.webidl',
     'ImageData.webidl',
     'ImageDocument.webidl',
     'InputEvent.webidl',
     'InputMethod.webidl',
     'InputPort.webidl',