diff --git a/scripts/led-matrix-viz.py b/scripts/led-matrix-viz.py
index 92649a7..42c8d95 100755
--- a/scripts/led-matrix-viz.py
+++ b/scripts/led-matrix-viz.py
@@ -23,9 +23,6 @@ AUDIO_COL = 4
 NOTE_ROWS = 7
 NOTE_ROW_OFFSET = 1
 
-AUDIO_SIGNAL_FILE = "/tmp/audio-signal-detect"
-
-
 def _check_services():
     global STATUS_CACHE, LAST_STATUS_CHECK
     now = time.monotonic()
@@ -37,7 +34,6 @@ def _check_services():
             STATUS_CACHE[svc] = r.stdout.strip() == "active"
         except Exception:
             STATUS_CACHE[svc] = False
-    STATUS_CACHE["audio"] = os.path.exists(AUDIO_SIGNAL_FILE) and (time.time() - os.path.getmtime(AUDIO_SIGNAL_FILE) < 5.0)
     LAST_STATUS_CHECK = now
     return STATUS_CACHE
 
@@ -68,12 +64,12 @@ def render(active_notes):
         col = SERVICE_COLS[idx]
         if status.get(svc):
             pixels[STATUS_ROW][col] = 1
-    if status.get("audio"):
+    if len(active_notes) > 0:
         pixels[STATUS_ROW][AUDIO_COL] = 1
     return pack_frame(pixels)
 
 
-def _diag_frame():
+def _diag_frame(active_notes):
     pixels = [[0] * COLS for _ in range(ROWS)]
     status = _check_services()
     for idx, svc in enumerate(SERVICES):
@@ -81,7 +77,7 @@ def _diag_frame():
         if status.get(svc):
             for r in range(ROWS):
                 pixels[r][col] = 1
-    if status.get("audio"):
+    if len(active_notes) > 0:
         for r in range(ROWS):
             pixels[r][AUDIO_COL] = 1
     return pack_frame(pixels)
@@ -166,7 +162,7 @@ def main():
             diag_start = now
             pre_diag_params = last_sent_params
             msg_id = (msg_id + 1) % 65535
-            router, ok = _send_frame(router, packer, _diag_frame(), msg_id)
+            router, ok = _send_frame(router, packer, _diag_frame(active_notes), msg_id)
             if ok:
                 frames_sent += 1