diff --git a/app/InCallService/src/org/lineageos/mediatek/incallservice/GainUtils.java b/app/InCallService/src/org/lineageos/mediatek/incallservice/GainUtils.java
new file mode 100644
index 0000000..2588c79
--- /dev/null
+++ b/app/InCallService/src/org/lineageos/mediatek/incallservice/GainUtils.java
@@ -0,0 +1,16 @@
+package org.lineageos.mediatek.incallservice;
+
+import android.media.AudioSystem;
+
+import android.util.Log;
+
+public class GainUtils {
+    public static final String LOG_TAG = "MediatekInCallService";
+
+    public static void setGainLevel(int audioDevice, int gainIndex, int streamType) {
+        String parameters = String.format("volumeDevice=%d;volumeIndex=%d;volumeStreamType=%d",
+                                          audioDevice, Math.min(7, gainIndex), streamType);
+        Log.d(LOG_TAG, "Setting audio parameters to: " + parameters);
+        AudioSystem.setParameters(parameters);
+    }
+}
diff --git a/app/InCallService/src/org/lineageos/mediatek/incallservice/VolumeChangeReceiver.java b/app/InCallService/src/org/lineageos/mediatek/incallservice/VolumeChangeReceiver.java
index 16f2770..98d1d39 100644
--- a/app/InCallService/src/org/lineageos/mediatek/incallservice/VolumeChangeReceiver.java
+++ b/app/InCallService/src/org/lineageos/mediatek/incallservice/VolumeChangeReceiver.java
@@ -15,32 +15,27 @@ public class VolumeChangeReceiver extends BroadcastReceiver {
 
     private AudioManager mAudioManager;
 
-    public VolumeChangeReceiver(Context context) {
-        mAudioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
+    public VolumeChangeReceiver(AudioManager audioManager) {
+        mAudioManager = audioManager;
     }
 
-    @Override
-    public void onReceive(Context context, Intent intent) {
-        int streamType = intent.getIntExtra(AudioManager.EXTRA_VOLUME_STREAM_TYPE, -1);
-        if (streamType == AudioSystem.STREAM_VOICE_CALL) {
+    private void handleVolumeStateChange(Intent intent) {
+        if (intent.getIntExtra(AudioManager.EXTRA_VOLUME_STREAM_TYPE, -1) == AudioManager.STREAM_VOICE_CALL) {
             AudioDeviceInfo callDevice = mAudioManager.getCommunicationDevice();
 
-            // Start building parameters
-            String parameters = "volumeDevice=" + (callDevice.getId() - 1) + ";";
+            // Try to get volumeIndex
             int volumeIndex = intent.getIntExtra(AudioManager.EXTRA_VOLUME_STREAM_VALUE, -1);
             if (volumeIndex < 0) {
                 Log.w(LOG_TAG, "Could not get volumeIndex!");
                 return;
             }
 
-            // Limit volumeIndex to a max of 7 since that's the size of
-            // MediaTek's gain table.
-            parameters += "volumeIndex=" + Math.min(7, volumeIndex) + ";";
-            parameters += "volumeStreamType=" + streamType;
-
-            // Set gain parameters
-            Log.d(LOG_TAG, "Setting audio parameters: " + parameters);
-            AudioSystem.setParameters(parameters);
+            GainUtils.setGainLevel(callDevice.getPort().type(), volumeIndex, AudioSystem.STREAM_VOICE_CALL);
         }
     }
+
+    @Override
+    public void onReceive(Context context, Intent intent) {
+            handleVolumeStateChange(intent);
+    }
 }
diff --git a/app/InCallService/src/org/lineageos/mediatek/incallservice/VolumeChangeService.java b/app/InCallService/src/org/lineageos/mediatek/incallservice/VolumeChangeService.java
index e15f47f..daca4d6 100644
--- a/app/InCallService/src/org/lineageos/mediatek/incallservice/VolumeChangeService.java
+++ b/app/InCallService/src/org/lineageos/mediatek/incallservice/VolumeChangeService.java
@@ -29,9 +29,12 @@ public class VolumeChangeService extends Service {
     @Override
     public int onStartCommand(Intent intent, int flags, int startid) {
         mContext = this;
-        mVolumeChangeReceiver = new VolumeChangeReceiver(mContext);
+
+        AudioManager audioManager = (AudioManager) mContext.getSystemService(Context.AUDIO_SERVICE);
+        mVolumeChangeReceiver = new VolumeChangeReceiver(audioManager);
 
         Log.i(LOG_TAG, "Service is starting...");
+
         this.registerReceiver(mVolumeChangeReceiver,
                                new IntentFilter(AudioManager.VOLUME_CHANGED_ACTION));
         return START_STICKY;