diff --git a/changelog.d/3243.bugfix b/changelog.d/3243.bugfix
new file mode 100644
index 0000000000..8c912a5c13
--- /dev/null
+++ b/changelog.d/3243.bugfix
@@ -0,0 +1 @@
+Notifications - Fix missing sound on notifications.
\ No newline at end of file
diff --git a/vector/src/main/java/im/vector/app/features/notifications/NotificationDrawerManager.kt b/vector/src/main/java/im/vector/app/features/notifications/NotificationDrawerManager.kt
index 37ed1e654a..fea4716b39 100644
--- a/vector/src/main/java/im/vector/app/features/notifications/NotificationDrawerManager.kt
+++ b/vector/src/main/java/im/vector/app/features/notifications/NotificationDrawerManager.kt
@@ -100,13 +100,14 @@ class NotificationDrawerManager @Inject constructor(private val context: Context
             if (existing != null) {
                 if (existing.isPushGatewayEvent) {
                     // Use the event coming from the event stream as it may contains more info than
-                    // the fcm one (like type/content/clear text)
+                    // the fcm one (like type/content/clear text) (e.g when an encrypted message from
+                    // FCM should be update with clear text after a sync)
                     // In this case the message has already been notified, and might have done some noise
                     // So we want the notification to be updated even if it has already been displayed
-                    // But it should make no noise (e.g when an encrypted message from FCM should be
-                    // update with clear text after a sync)
+                    // Use setOnlyAlertOnce to ensure update notification does not interfere with sound
+                    // from first notify invocation as outlined in:
+                    // https://developer.android.com/training/notify-user/build-notification#Updating
                     notifiableEvent.hasBeenDisplayed = false
-                    notifiableEvent.noisy = false
                     eventList.remove(existing)
                     eventList.add(notifiableEvent)
                 } else {
diff --git a/vector/src/main/java/im/vector/app/features/notifications/NotificationUtils.kt b/vector/src/main/java/im/vector/app/features/notifications/NotificationUtils.kt
index cf13150e59..33f419857b 100755
--- a/vector/src/main/java/im/vector/app/features/notifications/NotificationUtils.kt
+++ b/vector/src/main/java/im/vector/app/features/notifications/NotificationUtils.kt
@@ -540,6 +540,7 @@ class NotificationUtils @Inject constructor(private val context: Context,
 
         val channelID = if (roomInfo.shouldBing) NOISY_NOTIFICATION_CHANNEL_ID else SILENT_NOTIFICATION_CHANNEL_ID
         return NotificationCompat.Builder(context, channelID)
+                .setOnlyAlertOnce(true)
                 .setWhen(lastMessageTimestamp)
                 // MESSAGING_STYLE sets title and content for API 16 and above devices.
                 .setStyle(messageStyle)
@@ -641,6 +642,7 @@ class NotificationUtils @Inject constructor(private val context: Context,
         val channelID = if (inviteNotifiableEvent.noisy) NOISY_NOTIFICATION_CHANNEL_ID else SILENT_NOTIFICATION_CHANNEL_ID
 
         return NotificationCompat.Builder(context, channelID)
+                .setOnlyAlertOnce(true)
                 .setContentTitle(stringProvider.getString(R.string.app_name))
                 .setContentText(inviteNotifiableEvent.description)
                 .setGroup(stringProvider.getString(R.string.app_name))
@@ -704,6 +706,7 @@ class NotificationUtils @Inject constructor(private val context: Context,
         val channelID = if (simpleNotifiableEvent.noisy) NOISY_NOTIFICATION_CHANNEL_ID else SILENT_NOTIFICATION_CHANNEL_ID
 
         return NotificationCompat.Builder(context, channelID)
+                .setOnlyAlertOnce(true)
                 .setContentTitle(stringProvider.getString(R.string.app_name))
                 .setContentText(simpleNotifiableEvent.description)
                 .setGroup(stringProvider.getString(R.string.app_name))