diff --git a/dom/telephony/Telephony.cpp b/dom/telephony/Telephony.cpp
index 75734c97e93..6aafc045ff4 100644
--- a/dom/telephony/Telephony.cpp
+++ b/dom/telephony/Telephony.cpp
@@ -21,7 +21,7 @@
 #include "nsServiceManagerUtils.h"
 #include "nsThreadUtils.h"
 
-#include "AudioChannelAgent.h"
+#include "AudioChannelService.h"
 #include "CallsList.h"
 #include "TelephonyCall.h"
 #include "TelephonyCallGroup.h"
@@ -66,7 +66,8 @@ public:
 Telephony::Telephony(nsPIDOMWindow* aOwner)
   : DOMEventTargetHelper(aOwner),
     mIsAudioStartPlaying(false),
-    mAudioAgentNotify(nsIAudioChannelAgent::AUDIO_AGENT_NOTIFY)
+    mAudioAgentNotify(nsIAudioChannelAgent::AUDIO_AGENT_NOTIFY),
+    mHaveDispatchedInterruptBeginEvent(false)
 {
   MOZ_ASSERT(aOwner);
   nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aOwner);
@@ -77,6 +78,7 @@ Telephony::Telephony(nsPIDOMWindow* aOwner)
   MOZ_ASSERT(!rv.Failed());
 
   mReadyPromise = promise;
+  mMuted = AudioChannelService::IsAudioChannelMutedByDefault();
 }
 
 Telephony::~Telephony()
@@ -681,6 +683,22 @@ Telephony::WindowVolumeChanged(float aVolume, bool aMuted)
     return rv.StealNSResult();
   }
 
+  // These events will be triggered when the telephony is interrupted by other
+  // audio channel.
+  if (mMuted != aMuted) {
+    mMuted = aMuted;
+    // We should not dispatch "mozinterruptend" when the system app initializes
+    // the telephony audio from muted to unmuted at the first time. The event
+    // "mozinterruptend" must be dispatched after the "mozinterruptbegin".
+    if (!mHaveDispatchedInterruptBeginEvent && mMuted) {
+      DispatchTrustedEvent(NS_LITERAL_STRING("mozinterruptbegin"));
+      mHaveDispatchedInterruptBeginEvent = mMuted;
+    } else if (mHaveDispatchedInterruptBeginEvent && !mMuted) {
+      DispatchTrustedEvent(NS_LITERAL_STRING("mozinterruptend"));
+      mHaveDispatchedInterruptBeginEvent = mMuted;
+    }
+  }
+
   return NS_OK;
 }
 
diff --git a/dom/telephony/Telephony.h b/dom/telephony/Telephony.h
index 77863fec624..bf99917facb 100644
--- a/dom/telephony/Telephony.h
+++ b/dom/telephony/Telephony.h
@@ -61,6 +61,8 @@ class Telephony final : public DOMEventTargetHelper,
   bool mIsAudioStartPlaying;
 
   uint32_t mAudioAgentNotify;
+  bool mHaveDispatchedInterruptBeginEvent;
+  bool mMuted;
 
 public:
   NS_DECL_ISUPPORTS_INHERITED