diff --git a/core/java/android/service/voice/HotwordDetectionService.java b/core/java/android/service/voice/HotwordDetectionService.java
index 5f4117404181f..473e7ae76cc98 100644
--- a/core/java/android/service/voice/HotwordDetectionService.java
+++ b/core/java/android/service/voice/HotwordDetectionService.java
@@ -16,9 +16,6 @@
 
 package android.service.voice;
 
-import static com.android.internal.util.function.pooled.PooledLambda.obtainMessage;
-
-import android.annotation.CallSuper;
 import android.annotation.DurationMillisLong;
 import android.annotation.IntDef;
 import android.annotation.NonNull;
@@ -33,10 +30,8 @@ import android.content.Intent;
 import android.hardware.soundtrigger.SoundTrigger;
 import android.media.AudioFormat;
 import android.os.Bundle;
-import android.os.Handler;
 import android.os.IBinder;
 import android.os.IRemoteCallback;
-import android.os.Looper;
 import android.os.ParcelFileDescriptor;
 import android.os.PersistableBundle;
 import android.os.RemoteException;
@@ -67,6 +62,8 @@ import java.util.function.IntConsumer;
  * to inform the system that a keyphrase was not detected. The system then relays this result to
  * the {@link VoiceInteractionService} through {@link HotwordDetector.Callback}.
  *
+ * Note: Methods in this class may be called concurrently
+ *
  * @hide
  */
 @SystemApi
@@ -138,8 +135,6 @@ public abstract class HotwordDetectionService extends Service {
     public static final String SERVICE_INTERFACE =
             "android.service.voice.HotwordDetectionService";
 
-    private Handler mHandler;
-
     @Nullable
     private ContentCaptureManager mContentCaptureManager;
 
@@ -154,13 +149,12 @@ public abstract class HotwordDetectionService extends Service {
             if (DBG) {
                 Log.d(TAG, "#detectFromDspSource");
             }
-            mHandler.sendMessage(obtainMessage(HotwordDetectionService::onDetect,
-                    HotwordDetectionService.this,
+            HotwordDetectionService.this.onDetect(
                     new AlwaysOnHotwordDetector.EventPayload(
                             event.triggerInData, event.captureAvailable,
                             event.captureFormat, event.captureSession, event.data),
                     timeoutMillis,
-                    new Callback(callback)));
+                    new Callback(callback));
         }
 
         @Override
@@ -169,11 +163,10 @@ public abstract class HotwordDetectionService extends Service {
             if (DBG) {
                 Log.d(TAG, "#updateState");
             }
-            mHandler.sendMessage(obtainMessage(HotwordDetectionService::onUpdateStateInternal,
-                    HotwordDetectionService.this,
+            HotwordDetectionService.this.onUpdateStateInternal(
                     options,
                     sharedMemory,
-                    callback));
+                    callback);
         }
 
         @Override
@@ -189,19 +182,15 @@ public abstract class HotwordDetectionService extends Service {
             }
             switch (audioSource) {
                 case AUDIO_SOURCE_MICROPHONE:
-                    mHandler.sendMessage(obtainMessage(
-                            HotwordDetectionService::onDetect,
-                            HotwordDetectionService.this,
-                            new Callback(callback)));
+                    HotwordDetectionService.this.onDetect(
+                            new Callback(callback));
                     break;
                 case AUDIO_SOURCE_EXTERNAL:
-                    mHandler.sendMessage(obtainMessage(
-                            HotwordDetectionService::onDetect,
-                            HotwordDetectionService.this,
+                    HotwordDetectionService.this.onDetect(
                             audioStream,
                             audioFormat,
                             options,
-                            new Callback(callback)));
+                            new Callback(callback));
                     break;
                 default:
                     Log.i(TAG, "Unsupported audio source " + audioSource);
@@ -216,13 +205,6 @@ public abstract class HotwordDetectionService extends Service {
         }
     };
 
-    @CallSuper
-    @Override
-    public void onCreate() {
-        super.onCreate();
-        mHandler = Handler.createAsync(Looper.getMainLooper());
-    }
-
     @Override
     @Nullable
     public final IBinder onBind(@NonNull Intent intent) {