diff --git a/services/core/java/com/android/server/audio/AudioService.java b/services/core/java/com/android/server/audio/AudioService.java
index 387a2be41d3c4..f840f2d359d57 100755
--- a/services/core/java/com/android/server/audio/AudioService.java
+++ b/services/core/java/com/android/server/audio/AudioService.java
@@ -185,6 +185,9 @@ public class AudioService extends IAudioService.Stub
 
     private static final String TAG = "AS.AudioService";
 
+    private final AudioSystemAdapter mAudioSystem;
+    private final SystemServerAdapter mSystemServer;
+
     /** Debug audio mode */
     protected static final boolean DEBUG_MODE = false;
 
@@ -649,10 +652,19 @@ public class AudioService extends IAudioService.Stub
 
     /** @hide */
     public AudioService(Context context) {
+        this(context, AudioSystemAdapter.getDefaultAdapter(),
+                SystemServerAdapter.getDefaultAdapter(context));
+    }
+
+    public AudioService(Context context, AudioSystemAdapter audioSystem,
+            SystemServerAdapter systemServer) {
         mContext = context;
         mContentResolver = context.getContentResolver();
         mAppOps = (AppOpsManager)context.getSystemService(Context.APP_OPS_SERVICE);
 
+        mAudioSystem = audioSystem;
+        mSystemServer = systemServer;
+
         mPlatformType = AudioSystem.getPlatformType(context);
 
         mIsSingleVolume = AudioSystem.isSingleVolume(context);
@@ -842,11 +854,13 @@ public class AudioService extends IAudioService.Stub
 
         context.registerReceiverAsUser(mReceiver, UserHandle.ALL, intentFilter, null, null);
 
-        LocalServices.addService(AudioManagerInternal.class, new AudioServiceInternal());
+        if (mSystemServer.isPrivileged()) {
+            LocalServices.addService(AudioManagerInternal.class, new AudioServiceInternal());
 
-        mUserManagerInternal.addUserRestrictionsListener(mUserRestrictionsListener);
+            mUserManagerInternal.addUserRestrictionsListener(mUserRestrictionsListener);
 
-        mRecordMonitor.initMonitor();
+            mRecordMonitor.initMonitor();
+        }
 
         final float[] preScale = new float[3];
         preScale[0] = mContext.getResources().getFraction(
@@ -935,7 +949,7 @@ public class AudioService extends IAudioService.Stub
 
         onIndicateSystemReady();
 
-        mMicMuteFromSystemCached = AudioSystem.isMicrophoneMuted();
+        mMicMuteFromSystemCached = mAudioSystem.isMicrophoneMuted();
         setMicMuteFromSwitchInput();
     }
 
@@ -1636,12 +1650,15 @@ public class AudioService extends IAudioService.Stub
         }
 
         if (currentImeUid != mCurrentImeUid || forceUpdate) {
-            AudioSystem.setCurrentImeUid(currentImeUid);
+            mAudioSystem.setCurrentImeUid(currentImeUid);
             mCurrentImeUid = currentImeUid;
         }
     }
 
     private void readPersistedSettings() {
+        if (!mSystemServer.isPrivileged()) {
+            return;
+        }
         final ContentResolver cr = mContentResolver;
 
         int ringerModeFromSettings =
@@ -1712,6 +1729,9 @@ public class AudioService extends IAudioService.Stub
     }
 
     private void readUserRestrictions() {
+        if (!mSystemServer.isPrivileged()) {
+            return;
+        }
         final int currentUser = getCurrentUserId();
 
         // Check the current user restriction.
@@ -2782,6 +2802,9 @@ public class AudioService extends IAudioService.Stub
     }
 
     private void sendBroadcastToAll(Intent intent) {
+        if (!mSystemServer.isPrivileged()) {
+            return;
+        }
         intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY_BEFORE_BOOT);
         intent.addFlags(Intent.FLAG_RECEIVER_FOREGROUND);
         final long ident = Binder.clearCallingIdentity();
@@ -3174,12 +3197,12 @@ public class AudioService extends IAudioService.Stub
         }
         // only mute for the current user
         if (getCurrentUserId() == userId || userId == android.os.Process.SYSTEM_UID) {
-            final boolean currentMute = AudioSystem.isMicrophoneMuted();
+            final boolean currentMute = mAudioSystem.isMicrophoneMuted();
             final long identity = Binder.clearCallingIdentity();
-            final int ret = AudioSystem.muteMicrophone(muted);
+            final int ret = mAudioSystem.muteMicrophone(muted);
 
             // update cache with the real state independently from what was set
-            mMicMuteFromSystemCached = AudioSystem.isMicrophoneMuted();
+            mMicMuteFromSystemCached = mAudioSystem.isMicrophoneMuted();
             if (ret != AudioSystem.AUDIO_STATUS_OK) {
                 Log.e(TAG, "Error changing mic mute state to " + muted + " current:"
                         + mMicMuteFromSystemCached);
@@ -4518,6 +4541,9 @@ public class AudioService extends IAudioService.Stub
     }
 
     private void broadcastRingerMode(String action, int ringerMode) {
+        if (!mSystemServer.isPrivileged()) {
+            return;
+        }
         // Send sticky broadcast
         Intent broadcast = new Intent(action);
         broadcast.putExtra(AudioManager.EXTRA_RINGER_MODE, ringerMode);
@@ -4527,6 +4553,9 @@ public class AudioService extends IAudioService.Stub
     }
 
     private void broadcastVibrateSetting(int vibrateType) {
+        if (!mSystemServer.isPrivileged()) {
+            return;
+        }
         // Send broadcast
         if (mActivityManagerInternal.isSystemReady()) {
             Intent broadcast = new Intent(AudioManager.VIBRATE_SETTING_CHANGED_ACTION);
@@ -5258,6 +5287,9 @@ public class AudioService extends IAudioService.Stub
         }
 
         public int observeDevicesForStream_syncVSS(boolean checkOthers) {
+            if (!mSystemServer.isPrivileged()) {
+                return AudioSystem.DEVICE_NONE;
+            }
             final int devices = AudioSystem.getDevicesForStream(mStreamType);
             if (devices == mObservedDevices) {
                 return devices;
@@ -5998,10 +6030,7 @@ public class AudioService extends IAudioService.Stub
                     break;
 
                 case MSG_BROADCAST_MICROPHONE_MUTE:
-                    mContext.sendBroadcastAsUser(
-                            new Intent(AudioManager.ACTION_MICROPHONE_MUTE_CHANGED)
-                                    .setFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY),
-                                    UserHandle.ALL);
+                    mSystemServer.sendMicrophoneMuteChangedIntent();
                     break;
             }
         }
diff --git a/services/core/java/com/android/server/audio/AudioSystemAdapter.java b/services/core/java/com/android/server/audio/AudioSystemAdapter.java
index 9f8f9f8fddde4..40c13904fbc95 100644
--- a/services/core/java/com/android/server/audio/AudioSystemAdapter.java
+++ b/services/core/java/com/android/server/audio/AudioSystemAdapter.java
@@ -40,10 +40,11 @@ public class AudioSystemAdapter {
 
     /**
      * Create an adapter for AudioSystem that always succeeds, and does nothing.
-     * @return a no-op AudioSystem adapter
+     * Overridden methods can be configured
+     * @return a no-op AudioSystem adapter with configurable adapter
      */
-    static final @NonNull AudioSystemAdapter getAlwaysOkAdapter() {
-        return new AudioSystemOkAdapter();
+    static final @NonNull AudioSystemAdapter getConfigurableAdapter() {
+        return new AudioSystemConfigurableAdapter();
     }
 
     /**
@@ -113,10 +114,51 @@ public class AudioSystemAdapter {
         return AudioSystem.setParameters(keyValuePairs);
     }
 
-    //--------------------------------------------------------------------
-    protected static class AudioSystemOkAdapter extends AudioSystemAdapter {
-        private static final String TAG = "ASA";
+    /**
+     * Same as {@link AudioSystem#isMicrophoneMuted()}}
+     * Checks whether the microphone mute is on or off.
+     * @return true if microphone is muted, false if it's not
+     */
+    public boolean isMicrophoneMuted() {
+        return AudioSystem.isMicrophoneMuted();
+    }
 
+    /**
+     * Same as {@link AudioSystem#muteMicrophone(boolean)}
+     * Sets the microphone mute on or off.
+     *
+     * @param on set <var>true</var> to mute the microphone;
+     *           <var>false</var> to turn mute off
+     * @return command completion status see AUDIO_STATUS_OK, see AUDIO_STATUS_ERROR
+     */
+    public int muteMicrophone(boolean on) {
+        return AudioSystem.muteMicrophone(on);
+    }
+
+    /**
+     * Same as {@link AudioSystem#setCurrentImeUid(int)}
+     * Communicate UID of current InputMethodService to audio policy service.
+     */
+    public int setCurrentImeUid(int uid) {
+        return AudioSystem.setCurrentImeUid(uid);
+    }
+
+    //--------------------------------------------------------------------
+    protected static class AudioSystemConfigurableAdapter extends AudioSystemAdapter {
+        private static final String TAG = "ASA";
+        private boolean mIsMicMuted = false;
+        private boolean mMuteMicrophoneFails = false;
+
+        public void configureIsMicrophoneMuted(boolean muted) {
+            mIsMicMuted = muted;
+        }
+
+        public void configureMuteMicrophoneToFail(boolean fail) {
+            mMuteMicrophoneFails = fail;
+        }
+
+        //-----------------------------------------------------------------
+        // Overrides of AudioSystemAdapter
         @Override
         public int setDeviceConnectionState(int device, int state, String deviceAddress,
                                             String deviceName, int codecFormat) {
@@ -152,5 +194,24 @@ public class AudioSystemAdapter {
         public int setParameters(String keyValuePairs) {
             return AudioSystem.AUDIO_STATUS_OK;
         }
+
+        @Override
+        public boolean isMicrophoneMuted() {
+            return mIsMicMuted;
+        }
+
+        @Override
+        public int muteMicrophone(boolean on) {
+            if (mMuteMicrophoneFails) {
+                return AudioSystem.AUDIO_STATUS_ERROR;
+            }
+            mIsMicMuted = on;
+            return AudioSystem.AUDIO_STATUS_OK;
+        }
+
+        @Override
+        public int setCurrentImeUid(int uid) {
+            return AudioSystem.AUDIO_STATUS_OK;
+        }
     }
 }
diff --git a/services/core/java/com/android/server/audio/SystemServerAdapter.java b/services/core/java/com/android/server/audio/SystemServerAdapter.java
new file mode 100644
index 0000000000000..509f6be76f171
--- /dev/null
+++ b/services/core/java/com/android/server/audio/SystemServerAdapter.java
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.audio;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.content.Context;
+import android.content.Intent;
+import android.media.AudioManager;
+import android.os.UserHandle;
+
+/**
+ * Provides an adapter to access functionality reserved to components running in system_server
+ * Functionality such as sending privileged broadcasts is to be accessed through the default
+ * adapter, whereas tests can inject a no-op adapter.
+ */
+public class SystemServerAdapter {
+
+    protected final Context mContext;
+
+    private SystemServerAdapter(@Nullable Context context) {
+        mContext = context;
+    }
+    /**
+     * Create a wrapper around privileged functionality.
+     * @return the adapter
+     */
+    static final @NonNull SystemServerAdapter getDefaultAdapter(Context context) {
+        return new SystemServerAdapter(context);
+    }
+
+    /**
+     * Create an adapter that does nothing.
+     * Use for running non-privileged tests, such as unit tests
+     * @return a no-op adapter
+     */
+    static final @NonNull SystemServerAdapter getNoOpAdapter() {
+        return new NoOpSystemServerAdapter();
+    }
+
+    /**
+     * @return true if this is supposed to be run in system_server, false otherwise (e.g. for a
+     *     unit test)
+     */
+    public boolean isPrivileged() {
+        return true;
+    }
+
+    /**
+     * Broadcast ACTION_MICROPHONE_MUTE_CHANGED
+     */
+    public void sendMicrophoneMuteChangedIntent() {
+        mContext.sendBroadcastAsUser(
+                new Intent(AudioManager.ACTION_MICROPHONE_MUTE_CHANGED)
+                        .setFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY),
+                UserHandle.ALL);
+    }
+
+    //--------------------------------------------------------------------
+    protected static class NoOpSystemServerAdapter extends SystemServerAdapter {
+
+        NoOpSystemServerAdapter() {
+            super(null);
+        }
+
+        @Override
+        public boolean isPrivileged() {
+            return false;
+        }
+
+        @Override
+        public void sendMicrophoneMuteChangedIntent() {
+            // no-op
+        }
+    }
+}
diff --git a/services/tests/servicestests/AndroidManifest.xml b/services/tests/servicestests/AndroidManifest.xml
index 109c1191523b2..270a3b50b9343 100644
--- a/services/tests/servicestests/AndroidManifest.xml
+++ b/services/tests/servicestests/AndroidManifest.xml
@@ -78,6 +78,7 @@
     <uses-permission android:name="android.permission.DUMP"/>
     <uses-permission android:name="android.permission.READ_DREAM_STATE"/>
     <uses-permission android:name="android.permission.WRITE_DREAM_STATE"/>
+    <uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS"/>
 
     <!-- Uses API introduced in O (26) -->
     <uses-sdk android:minSdkVersion="1"
diff --git a/services/tests/servicestests/src/com/android/server/audio/AudioDeviceBrokerTest.java b/services/tests/servicestests/src/com/android/server/audio/AudioDeviceBrokerTest.java
index 73a191dc78ccc..22f8b9c8ae92b 100644
--- a/services/tests/servicestests/src/com/android/server/audio/AudioDeviceBrokerTest.java
+++ b/services/tests/servicestests/src/com/android/server/audio/AudioDeviceBrokerTest.java
@@ -66,7 +66,7 @@ public class AudioDeviceBrokerTest {
         mContext = InstrumentationRegistry.getTargetContext();
 
         mMockAudioService = mock(AudioService.class);
-        mSpyAudioSystem = spy(AudioSystemAdapter.getAlwaysOkAdapter());
+        mSpyAudioSystem = spy(AudioSystemAdapter.getConfigurableAdapter());
         mSpyDevInventory = spy(new AudioDeviceInventory(mSpyAudioSystem));
         mAudioDeviceBroker = new AudioDeviceBroker(mContext, mMockAudioService, mSpyDevInventory);
         mSpyDevInventory.setDeviceBroker(mAudioDeviceBroker);
diff --git a/services/tests/servicestests/src/com/android/server/audio/AudioServiceTest.java b/services/tests/servicestests/src/com/android/server/audio/AudioServiceTest.java
new file mode 100644
index 0000000000000..6185ae6d93f94
--- /dev/null
+++ b/services/tests/servicestests/src/com/android/server/audio/AudioServiceTest.java
@@ -0,0 +1,115 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.server.audio;
+
+import static org.mockito.Mockito.reset;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+
+import android.content.Context;
+import android.os.Looper;
+import android.os.UserHandle;
+import android.util.Log;
+
+import androidx.test.InstrumentationRegistry;
+import androidx.test.filters.MediumTest;
+import androidx.test.runner.AndroidJUnit4;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Spy;
+
+@MediumTest
+@RunWith(AndroidJUnit4.class)
+public class AudioServiceTest {
+    private static final String TAG = "AudioServiceTest";
+
+    private static final int MAX_MESSAGE_HANDLING_DELAY_MS = 100;
+
+    private Context mContext;
+    private AudioSystemAdapter mAudioSystem;
+    @Spy private SystemServerAdapter mSpySystemServer;
+    // the class being unit-tested here
+    private AudioService mAudioService;
+
+    private static boolean sLooperPrepared = false;
+
+    @Before
+    public void setUp() throws Exception {
+        if (!sLooperPrepared) {
+            Looper.prepare();
+            sLooperPrepared = true;
+        }
+        mContext = InstrumentationRegistry.getTargetContext();
+        mAudioSystem = AudioSystemAdapter.getConfigurableAdapter();
+        mSpySystemServer = spy(SystemServerAdapter.getNoOpAdapter());
+        mAudioService = new AudioService(mContext, mAudioSystem, mSpySystemServer);
+    }
+
+    /**
+     * Test muting the mic reports the expected value, and the corresponding intent was fired
+     * @throws Exception
+     */
+    @Test
+    public void testMuteMicrophone() throws Exception {
+        Log.i(TAG, "running testMuteMicrophone");
+        Assert.assertNotNull(mAudioService);
+        final AudioSystemAdapter.AudioSystemConfigurableAdapter testAudioSystem =
+                (AudioSystemAdapter.AudioSystemConfigurableAdapter) mAudioSystem;
+        testAudioSystem.configureMuteMicrophoneToFail(false);
+        for (boolean muted : new boolean[] { true, false}) {
+            testAudioSystem.configureIsMicrophoneMuted(!muted);
+            mAudioService.setMicrophoneMute(muted, mContext.getOpPackageName(),
+                    UserHandle.getCallingUserId());
+            Assert.assertEquals("mic mute reporting wrong value",
+                    muted, mAudioService.isMicrophoneMuted());
+            // verify the intent for mic mute changed is supposed to be fired
+            Thread.sleep(MAX_MESSAGE_HANDLING_DELAY_MS);
+            verify(mSpySystemServer, times(1))
+                    .sendMicrophoneMuteChangedIntent();
+            reset(mSpySystemServer);
+        }
+    }
+
+    /**
+     * Test muting the mic with simulated failure reports the expected value, and the corresponding
+     * intent was fired
+     * @throws Exception
+     */
+    @Test
+    public void testMuteMicrophoneWhenFail() throws Exception {
+        Log.i(TAG, "running testMuteMicrophoneWhenFail");
+        Assert.assertNotNull(mAudioService);
+        final AudioSystemAdapter.AudioSystemConfigurableAdapter testAudioSystem =
+                (AudioSystemAdapter.AudioSystemConfigurableAdapter) mAudioSystem;
+        testAudioSystem.configureMuteMicrophoneToFail(true);
+        for (boolean muted : new boolean[] { true, false}) {
+            testAudioSystem.configureIsMicrophoneMuted(!muted);
+            mAudioService.setMicrophoneMute(muted, mContext.getOpPackageName(),
+                    UserHandle.getCallingUserId());
+            Assert.assertEquals("mic mute reporting wrong value",
+                    !muted, mAudioService.isMicrophoneMuted());
+            // verify the intent for mic mute changed is supposed to be fired
+            Thread.sleep(MAX_MESSAGE_HANDLING_DELAY_MS);
+            verify(mSpySystemServer, times(1))
+                    .sendMicrophoneMuteChangedIntent();
+            reset(mSpySystemServer);
+        }
+    }
+}