diff --git a/static/js/modes/listening-post.js b/static/js/modes/listening-post.js
index 46e64c4..1af1aef 100644
--- a/static/js/modes/listening-post.js
+++ b/static/js/modes/listening-post.js
@@ -659,6 +659,8 @@ function handleSignalFound(data) {
                 scannerAudio.volume = knobValue / 100;
             }
             scannerAudio.play().catch(e => console.warn('[SCANNER] Audio autoplay blocked:', e));
+            // Initialize audio visualizer to feed signal levels to synthesizer
+            initAudioVisualizer();
         }
     }
 
@@ -2089,6 +2091,9 @@ async function _startDirectListenInternal() {
             console.log('[LISTEN] Initial play blocked, waiting for canplay');
         });
 
+        // Initialize audio visualizer to feed signal levels to synthesizer
+        initAudioVisualizer();
+
         isDirectListening = true;
         updateDirectListenUI(true, freq);
         addScannerLogEntry(`${freq.toFixed(3)} MHz (${currentModulation.toUpperCase()})`, '', 'signal');