diff --git a/services/audioflinger/PlaybackTracks.h b/services/audioflinger/PlaybackTracks.h
index 27e4627..02cac38 100644
--- a/services/audioflinger/PlaybackTracks.h
+++ b/services/audioflinger/PlaybackTracks.h
@@ -76,6 +76,13 @@
 
     virtual bool        isFastTrack() const { return (mFlags & AUDIO_OUTPUT_FLAG_FAST) != 0; }
 
+// implement volume handling.
+   VolumeShaper::Status applyVolumeShaper(
+                                const sp<VolumeShaper::Configuration>& configuration,
+                                const sp<VolumeShaper::Operation>& operation);
+sp<VolumeShaper::State> getVolumeShaperState(int id);
+    sp<VolumeHandler>   getVolumeHandler() { return mVolumeHandler; }
+
 protected:
     // for numerous
     friend class PlaybackThread;
@@ -153,6 +160,8 @@
 
     ExtendedTimestamp  mSinkTimestamp;
 
+    sp<VolumeHandler>  mVolumeHandler; // handles multiple VolumeShaper configs and operations
+
 private:
     // The following fields are only for fast tracks, and should be in a subclass
     int                 mFastIndex; // index within FastMixerState::mFastTracks[];