diff --git a/rpi/hardware/sound/sound.py b/rpi/hardware/sound/sound.py
index e377d46f..a376110f 100644
--- a/rpi/hardware/sound/sound.py
+++ b/rpi/hardware/sound/sound.py
@@ -40,14 +40,15 @@ class SoundReader:
 
     def _read(self):
         measure_iteration = 100
+        level = 0
         i = 0
         while self._running:
-            level = 0
             if GPIO.input(self._pin):
                 level += 1
             if i == measure_iteration:
                 self._notify(f'{{"soundSensorValue": {level}}}')
                 i = 0
+                level = 0
             i += 1
             time.sleep(0.02)