diff --git a/src/com/android/server/telecom/Call.java b/src/com/android/server/telecom/Call.java
index a933c79..15f9cd1 100644
--- a/src/com/android/server/telecom/Call.java
+++ b/src/com/android/server/telecom/Call.java
@@ -1925,6 +1925,13 @@
             if (didRttChange) {
                 if ((mConnectionProperties & Connection.PROPERTY_IS_RTT) ==
                         Connection.PROPERTY_IS_RTT) {
+                    // If we already had RTT streams up, that means that either the call started
+                    // with RTT or the user previously requested to start RTT. Either way, don't
+                    // play the alert tone.
+                    if (!areRttStreamsInitialized()) {
+                        mCallsManager.playRttUpgradeToneForCall(this);
+                    }
+
                     createRttStreams();
                     // Call startRtt to pass the RTT pipes down to the connection service.
                     // They already turned on the RTT property so no request should be sent.
diff --git a/src/com/android/server/telecom/CallAudioManager.java b/src/com/android/server/telecom/CallAudioManager.java
index a6509b4..6a7261e 100644
--- a/src/com/android/server/telecom/CallAudioManager.java
+++ b/src/com/android/server/telecom/CallAudioManager.java
@@ -264,6 +264,14 @@
         }
     }
 
+    public void playRttUpgradeTone(Call call) {
+        if (call != mForegroundCall) {
+            // We only play tones for foreground calls.
+            return;
+        }
+        mPlayerFactory.createPlayer(InCallTonePlayer.TONE_RTT_REQUEST).startTone();
+    }
+
     /**
      * Play or stop a call hold tone for a call.  Triggered via
      * {@link Connection#sendConnectionEvent(String)} when the
diff --git a/src/com/android/server/telecom/CallsManager.java b/src/com/android/server/telecom/CallsManager.java
index d532dbf..baced16 100755
--- a/src/com/android/server/telecom/CallsManager.java
+++ b/src/com/android/server/telecom/CallsManager.java
@@ -2744,6 +2744,16 @@
         updateCanAddCall();
     }
 
+    @Override
+    public void onRemoteRttRequest(Call call, int requestId) {
+        Log.i(this, "onRemoteRttRequest: call %s", call.getId());
+        playRttUpgradeToneForCall(call);
+    }
+
+    public void playRttUpgradeToneForCall(Call call) {
+        mCallAudioManager.playRttUpgradeTone(call);
+    }
+
     // Construct the list of possible PhoneAccounts that the outgoing call can use based on the
     // active calls in CallsManager. If any of the active calls are on a SIM based PhoneAccount,
     // then include only that SIM based PhoneAccount and any non-SIM PhoneAccounts, such as SIP.
diff --git a/src/com/android/server/telecom/InCallTonePlayer.java b/src/com/android/server/telecom/InCallTonePlayer.java
index 4f0cf8d..814c730 100644
--- a/src/com/android/server/telecom/InCallTonePlayer.java
+++ b/src/com/android/server/telecom/InCallTonePlayer.java
@@ -162,6 +162,7 @@
     public static final int TONE_UNOBTAINABLE_NUMBER = 12;
     public static final int TONE_VOICE_PRIVACY = 13;
     public static final int TONE_VIDEO_UPGRADE = 14;
+    public static final int TONE_RTT_REQUEST = 15;
 
     private static final int TONE_RESOURCE_ID_UNDEFINED = -1;
 
@@ -329,6 +330,7 @@
                     // TODO: fill in.
                     throw new IllegalStateException("Voice privacy tone NYI.");
                 case TONE_VIDEO_UPGRADE:
+                case TONE_RTT_REQUEST:
                     // Similar to the call waiting tone, but does not repeat.
                     toneType = ToneGenerator.TONE_SUP_CALL_WAITING;
                     toneVolume = RELATIVE_VOLUME_HIPRI;