diff --git a/assignment-client/src/audio/AudioMixerClientData.cpp b/assignment-client/src/audio/AudioMixerClientData.cpp
index 07fa337a57..a5f5521a2d 100644
--- a/assignment-client/src/audio/AudioMixerClientData.cpp
+++ b/assignment-client/src/audio/AudioMixerClientData.cpp
@@ -226,11 +226,31 @@ AvatarAudioStream* AudioMixerClientData::getAvatarAudioStream() {
     return NULL;
 }
 
+AudioHRTF& AudioMixerClientData::hrtfForStream(Node::LocalID nodeID, const QUuid& streamID) {
+    auto& hrtfVector = _nodeSourcesHRTFMap[nodeID];
+
+    auto streamIt = std::find_if(hrtfVector.begin(), hrtfVector.end(), [&streamID](IdentifiedHRTF& identifiedHRTF){
+        return identifiedHRTF.streamIdentifier == streamID;
+    });
+
+    if (streamIt == hrtfVector.end()) {
+        hrtfVector.push_back({ streamID, std::unique_ptr<AudioHRTF>(new AudioHRTF) });
+
+        return *hrtfVector.back().hrtf;
+    } else {
+        return *streamIt->hrtf;
+    }
+}
+
 void AudioMixerClientData::removeHRTFForStream(Node::LocalID nodeID, const QUuid& streamID) {
     auto it = _nodeSourcesHRTFMap.find(nodeID);
     if (it != _nodeSourcesHRTFMap.end()) {
+        auto streamIt = std::find_if(it->second.begin(), it->second.end(), [&streamID](IdentifiedHRTF& identifiedHRTF){
+            return identifiedHRTF.streamIdentifier == streamID;
+        });
+
         // erase the stream with the given ID from the given node
-        it->second.erase(streamID);
+        it->second.erase(streamIt);
 
         // is the map for this node now empty?
         // if so we can remove it
diff --git a/assignment-client/src/audio/AudioMixerClientData.h b/assignment-client/src/audio/AudioMixerClientData.h
index d74c8bb6a4..a35f3dea5a 100644
--- a/assignment-client/src/audio/AudioMixerClientData.h
+++ b/assignment-client/src/audio/AudioMixerClientData.h
@@ -50,7 +50,7 @@ public:
     // they are not thread-safe
 
     // returns a new or existing HRTF object for the given stream from the given node
-    AudioHRTF& hrtfForStream(Node::LocalID nodeID, const QUuid& streamID = QUuid()) { return _nodeSourcesHRTFMap[nodeID][streamID]; }
+    AudioHRTF& hrtfForStream(Node::LocalID nodeID, const QUuid& streamID = QUuid());
 
     // removes an AudioHRTF object for a given stream
     void removeHRTFForStream(Node::LocalID nodeID, const QUuid& streamID = QUuid());
@@ -152,8 +152,13 @@ private:
     };
     IgnoreZoneMemo _ignoreZone;
 
-    using HRTFMap = std::unordered_map<QUuid, AudioHRTF>;
-    using NodeSourcesHRTFMap = std::unordered_map<Node::LocalID, HRTFMap>;
+    struct IdentifiedHRTF {
+        QUuid streamIdentifier;
+        std::unique_ptr<AudioHRTF> hrtf;
+    };
+
+    using HRTFVector = std::vector<IdentifiedHRTF>;
+    using NodeSourcesHRTFMap = std::unordered_map<Node::LocalID, HRTFVector>;
     NodeSourcesHRTFMap _nodeSourcesHRTFMap;
 
     quint16 _outgoingMixedAudioSequenceNumber;