diff --git a/My project/Assets/FlowScope/Tests/PlayMode/Audio/AudioServiceTests.cs b/My project/Assets/FlowScope/Tests/PlayMode/Audio/AudioServiceTests.cs
index 4712cd5..95ed4df 100644
--- a/My project/Assets/FlowScope/Tests/PlayMode/Audio/AudioServiceTests.cs	
+++ b/My project/Assets/FlowScope/Tests/PlayMode/Audio/AudioServiceTests.cs	
@@ -17,6 +17,7 @@ namespace FlowScope.Tests.PlayMode.Audio
         private AudioClip bgmA;
         private AudioClip bgmB;
         private AudioClip sfx;
+        private GameObject listenerObject;
 
         [SetUp]
         public void SetUp()
@@ -29,6 +30,12 @@ namespace FlowScope.Tests.PlayMode.Audio
             resources.Add("bgm-a", bgmA);
             resources.Add("bgm-b", bgmB);
             resources.Add("sfx", sfx);
+
+            if (Object.FindObjectOfType<AudioListener>() == null)
+            {
+                listenerObject = new GameObject("AudioServiceTestListener");
+                listenerObject.AddComponent<AudioListener>();
+            }
         }
 
         [TearDown]
@@ -38,6 +45,11 @@ namespace FlowScope.Tests.PlayMode.Audio
             {
                 Object.Destroy(service.gameObject);
             }
+
+            if (listenerObject != null)
+            {
+                Object.DestroyImmediate(listenerObject);
+            }
         }
 
         [UnityTest]
@@ -129,10 +141,15 @@ namespace FlowScope.Tests.PlayMode.Audio
 
             handle.Stop(0.1f);
 
-            yield return new WaitForSeconds(0.15f);
-            Assert.That(handle.IsPlaying, Is.False);
-            Assert.That(bgmSource.isPlaying, Is.False);
-            Assert.That(bgmSource.volume, Is.EqualTo(0f).Within(0.01f));
+            yield return WaitUntilOrFail(
+                () => bgmSource == null || (!bgmSource.isPlaying && bgmSource.volume <= 0.01f),
+                1f,
+                "BGM fade-out did not stop and reach zero volume.");
+            if (bgmSource != null)
+            {
+                Assert.That(bgmSource.isPlaying, Is.False);
+                Assert.That(bgmSource.volume, Is.EqualTo(0f).Within(0.01f));
+            }
         }
 
         [Test]
@@ -151,6 +168,20 @@ namespace FlowScope.Tests.PlayMode.Audio
             return gameObject.AddComponent<AudioService>().Initialize(resources, config);
         }
 
+        private static System.Collections.IEnumerator WaitUntilOrFail(
+            Func<bool> condition,
+            float timeoutSeconds,
+            string message)
+        {
+            var deadline = Time.realtimeSinceStartup + timeoutSeconds;
+            while (!condition() && Time.realtimeSinceStartup < deadline)
+            {
+                yield return null;
+            }
+
+            Assert.That(condition(), Is.True, message);
+        }
+
         private static AudioClip CreateClip(string name, float lengthSeconds)
         {
             var sampleCount = Mathf.CeilToInt(44100 * lengthSeconds);