diff --git a/assignment-client/src/audio/AudioMixerClientData.h b/assignment-client/src/audio/AudioMixerClientData.h
index 653749f619..f9d113c53d 100644
--- a/assignment-client/src/audio/AudioMixerClientData.h
+++ b/assignment-client/src/audio/AudioMixerClientData.h
@@ -84,6 +84,8 @@ public:
 
     float getMasterAvatarGain() const { return _masterAvatarGain; }
     void setMasterAvatarGain(float gain) { _masterAvatarGain = gain; }
+    float getMasterInjectorGain() const { return _masterInjectorGain; }
+    void setMasterInjectorGain(float gain) { _masterInjectorGain = gain; }
 
     AudioLimiter audioLimiter;
 
@@ -189,6 +191,7 @@ private:
     int _frameToSendStats { 0 };
 
     float _masterAvatarGain { 1.0f };   // per-listener mixing gain, applied only to avatars
+    float _masterInjectorGain { 1.0f }; // per-listener mixing gain, applied only to injectors
 
     CodecPluginPointer _codec;
     QString _selectedCodecName;
diff --git a/assignment-client/src/audio/AudioMixerSlave.cpp b/assignment-client/src/audio/AudioMixerSlave.cpp
index a920b45161..f7f8e8a9c1 100644
--- a/assignment-client/src/audio/AudioMixerSlave.cpp
+++ b/assignment-client/src/audio/AudioMixerSlave.cpp
@@ -50,7 +50,7 @@ void sendEnvironmentPacket(const SharedNodePointer& node, AudioMixerClientData&
 
 // mix helpers
 inline float approximateGain(const AvatarAudioStream& listeningNodeStream, const PositionalAudioStream& streamToAdd);
-inline float computeGain(float masterListenerGain, const AvatarAudioStream& listeningNodeStream,
+inline float computeGain(float masterAvatarGain, float masterInjectorGain, const AvatarAudioStream& listeningNodeStream,
         const PositionalAudioStream& streamToAdd, const glm::vec3& relativePosition, float distance, bool isEcho);
 inline float computeAzimuth(const AvatarAudioStream& listeningNodeStream, const PositionalAudioStream& streamToAdd,
         const glm::vec3& relativePosition);
@@ -338,8 +338,8 @@ bool AudioMixerSlave::prepareMix(const SharedNodePointer& listener) {
         }
 
         if (!isThrottling) {
-            updateHRTFParameters(stream, *listenerAudioStream,
-                                 listenerData->getMasterAvatarGain());
+            updateHRTFParameters(stream, *listenerAudioStream, listenerData->getMasterAvatarGain(),
+                                 listenerData->getMasterInjectorGain());
         }
         return false;
     });
@@ -363,8 +363,8 @@ bool AudioMixerSlave::prepareMix(const SharedNodePointer& listener) {
         }
 
         if (!isThrottling) {
-            updateHRTFParameters(stream, *listenerAudioStream,
-                                 listenerData->getMasterAvatarGain());
+            updateHRTFParameters(stream, *listenerAudioStream, listenerData->getMasterAvatarGain(),
+                                 listenerData->getMasterInjectorGain());
         }
         return false;
     });
@@ -381,13 +381,13 @@ bool AudioMixerSlave::prepareMix(const SharedNodePointer& listener) {
             stream.approximateVolume = approximateVolume(stream, listenerAudioStream);
         } else {
             if (shouldBeSkipped(stream, *listener, *listenerAudioStream, *listenerData)) {
-                addStream(stream, *listenerAudioStream, 0.0f, isSoloing);
+                addStream(stream, *listenerAudioStream, 0.0f, 0.0f, isSoloing);
                 streams.skipped.push_back(move(stream));
                 ++stats.activeToSkipped;
                 return true;
             }
 
-            addStream(stream, *listenerAudioStream, listenerData->getMasterAvatarGain(),
+            addStream(stream, *listenerAudioStream, listenerData->getMasterAvatarGain(), listenerData->getMasterInjectorGain(),
                       isSoloing);
 
             if (shouldBeInactive(stream)) {
@@ -423,7 +423,7 @@ bool AudioMixerSlave::prepareMix(const SharedNodePointer& listener) {
                 return true;
             }
 
-            addStream(stream, *listenerAudioStream, listenerData->getMasterAvatarGain(),
+            addStream(stream, *listenerAudioStream, listenerData->getMasterAvatarGain(), listenerData->getMasterInjectorGain(),
                       isSoloing);
 
             if (shouldBeInactive(stream)) {
@@ -491,7 +491,9 @@ bool AudioMixerSlave::prepareMix(const SharedNodePointer& listener) {
 
 void AudioMixerSlave::addStream(AudioMixerClientData::MixableStream& mixableStream,
                                 AvatarAudioStream& listeningNodeStream,
-                                float masterListenerGain, bool isSoloing) {
+                                float masterAvatarGain,
+                                float masterInjectorGain,
+                                bool isSoloing) {
     ++stats.totalMixes;
 
     auto streamToAdd = mixableStream.positionalStream;
@@ -504,9 +506,10 @@ void AudioMixerSlave::addStream(AudioMixerClientData::MixableStream& mixableStre
     float distance = glm::max(glm::length(relativePosition), EPSILON);
     float azimuth = isEcho ? 0.0f : computeAzimuth(listeningNodeStream, listeningNodeStream, relativePosition);
 
-    float gain = masterListenerGain;
+    float gain = masterAvatarGain;
     if (!isSoloing) {
-        gain = computeGain(masterListenerGain, listeningNodeStream, *streamToAdd, relativePosition, distance, isEcho);
+        gain = computeGain(masterAvatarGain, masterInjectorGain, listeningNodeStream, *streamToAdd, relativePosition,
+                           distance, isEcho);
     }
 
     const int HRTF_DATASET_INDEX = 1;
@@ -585,8 +588,9 @@ void AudioMixerSlave::addStream(AudioMixerClientData::MixableStream& mixableStre
 }
 
 void AudioMixerSlave::updateHRTFParameters(AudioMixerClientData::MixableStream& mixableStream,
-                                      AvatarAudioStream& listeningNodeStream,
-                                      float masterListenerGain) {
+                                           AvatarAudioStream& listeningNodeStream,
+                                           float masterAvatarGain,
+                                           float masterInjectorGain) {
     auto streamToAdd = mixableStream.positionalStream;
 
     // check if this is a server echo of a source back to itself
@@ -595,7 +599,8 @@ void AudioMixerSlave::updateHRTFParameters(AudioMixerClientData::MixableStream&
     glm::vec3 relativePosition = streamToAdd->getPosition() - listeningNodeStream.getPosition();
 
     float distance = glm::max(glm::length(relativePosition), EPSILON);
-    float gain = computeGain(masterListenerGain, listeningNodeStream, *streamToAdd, relativePosition, distance, isEcho);
+    float gain = computeGain(masterAvatarGain, masterInjectorGain, listeningNodeStream, *streamToAdd, relativePosition,
+                             distance, isEcho);
     float azimuth = isEcho ? 0.0f : computeAzimuth(listeningNodeStream, listeningNodeStream, relativePosition);
 
     mixableStream.hrtf->setParameterHistory(azimuth, distance, gain);
@@ -720,6 +725,7 @@ float approximateGain(const AvatarAudioStream& listeningNodeStream, const Positi
     // injector: apply attenuation
     if (streamToAdd.getType() == PositionalAudioStream::Injector) {
         gain *= reinterpret_cast<const InjectedAudioStream*>(&streamToAdd)->getAttenuationRatio();
+        // injector: skip master gain
     }
 
     // avatar: skip attenuation - it is too costly to approximate
@@ -729,16 +735,23 @@ float approximateGain(const AvatarAudioStream& listeningNodeStream, const Positi
     float distance = glm::length(relativePosition);
     return gain / distance;
 
-    // avatar: skip master gain - it is constant for all streams
+    // avatar: skip master gain
 }
 
-float computeGain(float masterListenerGain, const AvatarAudioStream& listeningNodeStream,
-        const PositionalAudioStream& streamToAdd, const glm::vec3& relativePosition, float distance, bool isEcho) {
+float computeGain(float masterAvatarGain,
+                  float masterInjectorGain,
+                  const AvatarAudioStream& listeningNodeStream,
+                  const PositionalAudioStream& streamToAdd,
+                  const glm::vec3& relativePosition,
+                  float distance,
+                  bool isEcho) {
     float gain = 1.0f;
 
     // injector: apply attenuation
     if (streamToAdd.getType() == PositionalAudioStream::Injector) {
         gain *= reinterpret_cast<const InjectedAudioStream*>(&streamToAdd)->getAttenuationRatio();
+        // apply master gain
+        gain *= masterInjectorGain;
 
     // avatar: apply fixed off-axis attenuation to make them quieter as they turn away
     } else if (!isEcho && (streamToAdd.getType() == PositionalAudioStream::Microphone)) {
@@ -754,8 +767,8 @@ float computeGain(float masterListenerGain, const AvatarAudioStream& listeningNo
 
         gain *= offAxisCoefficient;
 
-        // apply master gain, only to avatars
-        gain *= masterListenerGain;
+        // apply master gain
+        gain *= masterAvatarGain;
     }
 
     auto& audioZones = AudioMixer::getAudioZones();
@@ -797,8 +810,9 @@ float computeGain(float masterListenerGain, const AvatarAudioStream& listeningNo
     return gain;
 }
 
-float computeAzimuth(const AvatarAudioStream& listeningNodeStream, const PositionalAudioStream& streamToAdd,
-        const glm::vec3& relativePosition) {
+float computeAzimuth(const AvatarAudioStream& listeningNodeStream,
+                     const PositionalAudioStream& streamToAdd,
+                     const glm::vec3& relativePosition) {
     glm::quat inverseOrientation = glm::inverse(listeningNodeStream.getOrientation());
 
     glm::vec3 rotatedSourcePosition = inverseOrientation * relativePosition;
diff --git a/assignment-client/src/audio/AudioMixerSlave.h b/assignment-client/src/audio/AudioMixerSlave.h
index 3d979da1fc..9765ea8639 100644
--- a/assignment-client/src/audio/AudioMixerSlave.h
+++ b/assignment-client/src/audio/AudioMixerSlave.h
@@ -57,10 +57,13 @@ private:
     bool prepareMix(const SharedNodePointer& listener);
     void addStream(AudioMixerClientData::MixableStream& mixableStream,
                    AvatarAudioStream& listeningNodeStream,
-                   float masterListenerGain, bool isSoloing);
+                   float masterAvatarGain,
+                   float masterInjectorGain,
+                   bool isSoloing);
     void updateHRTFParameters(AudioMixerClientData::MixableStream& mixableStream,
                               AvatarAudioStream& listeningNodeStream,
-                              float masterListenerGain);
+                              float masterAvatarGain,
+                              float masterInjectorGain);
     void resetHRTFState(AudioMixerClientData::MixableStream& mixableStream);
 
     void addStreams(Node& listener, AudioMixerClientData& listenerData);