diff --git a/src/main/java/org/jitsi/jigasi/TranscriptionGatewaySession.java b/src/main/java/org/jitsi/jigasi/TranscriptionGatewaySession.java
index 03b7c134..797f187f 100644
--- a/src/main/java/org/jitsi/jigasi/TranscriptionGatewaySession.java
+++ b/src/main/java/org/jitsi/jigasi/TranscriptionGatewaySession.java
@@ -19,7 +19,6 @@
 
 import net.java.sip.communicator.impl.protocol.jabber.*;
 import net.java.sip.communicator.service.protocol.*;
-import net.java.sip.communicator.service.protocol.Message;
 import net.java.sip.communicator.service.protocol.event.*;
 import net.java.sip.communicator.service.protocol.media.*;
 import org.jitsi.utils.concurrent.*;
@@ -38,6 +37,7 @@
 
 import java.util.*;
 import java.util.concurrent.*;
+import java.util.concurrent.atomic.*;
 
 /**
  * A TranscriptionGatewaySession is able to join a JVB conference and
@@ -354,26 +354,32 @@ void notifyChatRoomMemberLeft(ChatRoomMember chatMember)
      **/
     private void flushParticipantTranscriptionBufferOnMute(ChatRoomMember chatMember, Presence presence)
     {
-        boolean hasMuted = false;
-        StandardExtensionElement sourceInfo = (StandardExtensionElement) presence.getExtensionElement("SourceInfo",
-                "jabber:client");
+        final AtomicBoolean muted = new AtomicBoolean(false);
+        StandardExtensionElement sourceInfo =
+            (StandardExtensionElement) presence.getExtensionElement("SourceInfo", "jabber:client");
         if (sourceInfo != null)
         {
             String mutedText = sourceInfo.getText();
             JSONParser jsonParser = new JSONParser();
             try
             {
-                JSONObject jsonObject = (JSONObject) jsonParser.parse(mutedText);
-                String participantKey = jsonObject.keySet().toArray()[0].toString();
-                JSONObject mutedJsonObject = (JSONObject) jsonParser.parse(jsonObject.get(participantKey).toString());
-                hasMuted = (boolean) mutedJsonObject.get("muted");
+                HashMap<String, JSONObject> jsonObject = (HashMap<String, JSONObject>) jsonParser.parse(mutedText);
+                jsonObject.forEach((key, value) ->
+                {
+                    // check only audio source info
+                    if (key.endsWith("a0"))
+                    {
+                        Object isMuted = value.get("muted");
+                        muted.set(isMuted != null && (boolean) isMuted);
+                    }
+                });
             }
             catch (Exception e)
             {
                 logger.error(this.callContext + " Error parsing presence while checking if participant is muted", e);
             }
 
-            if (hasMuted)
+            if (muted.get())
             {
                 this.transcriber.flushParticipantAudioBuffer(getParticipantIdentifier(chatMember));
             }