diff --git a/soundtrigger/2.0/default/SoundTriggerHalImpl.h b/soundtrigger/2.0/default/SoundTriggerHalImpl.h
index 2dd7166..5a9f0e1 100644
--- a/soundtrigger/2.0/default/SoundTriggerHalImpl.h
+++ b/soundtrigger/2.0/default/SoundTriggerHalImpl.h
@@ -35,50 +35,115 @@
 using ::android::hardware::audio::common::V2_0::Uuid;
 using ::android::hardware::soundtrigger::V2_0::ISoundTriggerHwCallback;
 
-class SoundTriggerHalImpl : public ISoundTriggerHw {
+class SoundTriggerHalImpl : public RefBase {
    public:
     SoundTriggerHalImpl();
+    ISoundTriggerHw* getInterface() { return new TrampolineSoundTriggerHw_2_0(this); }
 
-    // Methods from ::android::hardware::soundtrigger::V2_0::ISoundTriggerHw follow.
-    Return<void> getProperties(getProperties_cb _hidl_cb) override;
-    Return<void> loadSoundModel(const ISoundTriggerHw::SoundModel& soundModel,
-                                const sp<ISoundTriggerHwCallback>& callback,
-                                ISoundTriggerHwCallback::CallbackCookie cookie,
-                                loadSoundModel_cb _hidl_cb) override;
-    Return<void> loadPhraseSoundModel(const ISoundTriggerHw::PhraseSoundModel& soundModel,
-                                      const sp<ISoundTriggerHwCallback>& callback,
-                                      ISoundTriggerHwCallback::CallbackCookie cookie,
-                                      loadPhraseSoundModel_cb _hidl_cb) override;
-
-    Return<int32_t> unloadSoundModel(SoundModelHandle modelHandle) override;
-    Return<int32_t> startRecognition(SoundModelHandle modelHandle,
-                                     const ISoundTriggerHw::RecognitionConfig& config,
-                                     const sp<ISoundTriggerHwCallback>& callback,
-                                     ISoundTriggerHwCallback::CallbackCookie cookie) override;
-    Return<int32_t> stopRecognition(SoundModelHandle modelHandle) override;
-    Return<int32_t> stopAllRecognitions() override;
-
-    // RefBase
-    virtual void onFirstRef();
-
-    static void soundModelCallback(struct sound_trigger_model_event* halEvent, void* cookie);
-    static void recognitionCallback(struct sound_trigger_recognition_event* halEvent, void* cookie);
-
-   private:
+   protected:
     class SoundModelClient : public RefBase {
        public:
-        SoundModelClient(uint32_t id, sp<ISoundTriggerHwCallback> callback,
-                         ISoundTriggerHwCallback::CallbackCookie cookie)
-            : mId(id), mCallback(callback), mCookie(cookie) {}
+        SoundModelClient(uint32_t id, ISoundTriggerHwCallback::CallbackCookie cookie)
+            : mId(id), mCookie(cookie) {}
         virtual ~SoundModelClient() {}
 
-        uint32_t mId;
+        uint32_t getId() const { return mId; }
+        sound_model_handle_t getHalHandle() const { return mHalHandle; }
+        void setHalHandle(sound_model_handle_t handle) { mHalHandle = handle; }
+
+        virtual void recognitionCallback(struct sound_trigger_recognition_event* halEvent) = 0;
+        virtual void soundModelCallback(struct sound_trigger_model_event* halEvent) = 0;
+
+       protected:
+        const uint32_t mId;
         sound_model_handle_t mHalHandle;
-        sp<ISoundTriggerHwCallback> mCallback;
         ISoundTriggerHwCallback::CallbackCookie mCookie;
     };
 
-    uint32_t nextUniqueId();
+    static void convertPhaseRecognitionEventFromHal(
+        ISoundTriggerHwCallback::PhraseRecognitionEvent* event,
+        const struct sound_trigger_phrase_recognition_event* halEvent);
+    static void convertRecognitionEventFromHal(
+        ISoundTriggerHwCallback::RecognitionEvent* event,
+        const struct sound_trigger_recognition_event* halEvent);
+    static void convertSoundModelEventFromHal(ISoundTriggerHwCallback::ModelEvent* event,
+                                              const struct sound_trigger_model_event* halEvent);
+
+    virtual ~SoundTriggerHalImpl();
+
+    Return<void> getProperties(ISoundTriggerHw::getProperties_cb _hidl_cb);
+    Return<void> loadSoundModel(const ISoundTriggerHw::SoundModel& soundModel,
+                                const sp<ISoundTriggerHwCallback>& callback,
+                                ISoundTriggerHwCallback::CallbackCookie cookie,
+                                ISoundTriggerHw::loadSoundModel_cb _hidl_cb);
+    Return<void> loadPhraseSoundModel(const ISoundTriggerHw::PhraseSoundModel& soundModel,
+                                      const sp<ISoundTriggerHwCallback>& callback,
+                                      ISoundTriggerHwCallback::CallbackCookie cookie,
+                                      ISoundTriggerHw::loadPhraseSoundModel_cb _hidl_cb);
+    Return<int32_t> unloadSoundModel(SoundModelHandle modelHandle);
+    Return<int32_t> startRecognition(SoundModelHandle modelHandle,
+                                     const ISoundTriggerHw::RecognitionConfig& config);
+    Return<int32_t> stopRecognition(SoundModelHandle modelHandle);
+    Return<int32_t> stopAllRecognitions();
+
+    uint32_t nextUniqueModelId();
+    int doLoadSoundModel(const ISoundTriggerHw::SoundModel& soundModel,
+                         sp<SoundModelClient> client);
+
+    // RefBase
+    void onFirstRef() override;
+
+   private:
+    struct TrampolineSoundTriggerHw_2_0 : public ISoundTriggerHw {
+        explicit TrampolineSoundTriggerHw_2_0(sp<SoundTriggerHalImpl> impl) : mImpl(impl) {}
+
+        // Methods from ::android::hardware::soundtrigger::V2_0::ISoundTriggerHw follow.
+        Return<void> getProperties(getProperties_cb _hidl_cb) override {
+            return mImpl->getProperties(_hidl_cb);
+        }
+        Return<void> loadSoundModel(const ISoundTriggerHw::SoundModel& soundModel,
+                                    const sp<ISoundTriggerHwCallback>& callback,
+                                    ISoundTriggerHwCallback::CallbackCookie cookie,
+                                    loadSoundModel_cb _hidl_cb) override {
+            return mImpl->loadSoundModel(soundModel, callback, cookie, _hidl_cb);
+        }
+        Return<void> loadPhraseSoundModel(const ISoundTriggerHw::PhraseSoundModel& soundModel,
+                                          const sp<ISoundTriggerHwCallback>& callback,
+                                          ISoundTriggerHwCallback::CallbackCookie cookie,
+                                          loadPhraseSoundModel_cb _hidl_cb) override {
+            return mImpl->loadPhraseSoundModel(soundModel, callback, cookie, _hidl_cb);
+        }
+        Return<int32_t> unloadSoundModel(SoundModelHandle modelHandle) override {
+            return mImpl->unloadSoundModel(modelHandle);
+        }
+        Return<int32_t> startRecognition(
+            SoundModelHandle modelHandle, const ISoundTriggerHw::RecognitionConfig& config,
+            const sp<ISoundTriggerHwCallback>& /*callback*/,
+            ISoundTriggerHwCallback::CallbackCookie /*cookie*/) override {
+            return mImpl->startRecognition(modelHandle, config);
+        }
+        Return<int32_t> stopRecognition(SoundModelHandle modelHandle) override {
+            return mImpl->stopRecognition(modelHandle);
+        }
+        Return<int32_t> stopAllRecognitions() override { return mImpl->stopAllRecognitions(); }
+
+       private:
+        sp<SoundTriggerHalImpl> mImpl;
+    };
+
+    class SoundModelClient_2_0 : public SoundModelClient {
+       public:
+        SoundModelClient_2_0(uint32_t id, ISoundTriggerHwCallback::CallbackCookie cookie,
+                             sp<ISoundTriggerHwCallback> callback)
+            : SoundModelClient(id, cookie), mCallback(callback) {}
+
+        void recognitionCallback(struct sound_trigger_recognition_event* halEvent) override;
+        void soundModelCallback(struct sound_trigger_model_event* halEvent) override;
+
+       private:
+        sp<ISoundTriggerHwCallback> mCallback;
+    };
+
     void convertUuidFromHal(Uuid* uuid, const sound_trigger_uuid_t* halUuid);
     void convertUuidToHal(sound_trigger_uuid_t* halUuid, const Uuid* uuid);
     void convertPropertiesFromHal(ISoundTriggerHw::Properties* properties,
@@ -94,19 +159,12 @@
     struct sound_trigger_recognition_config* convertRecognitionConfigToHal(
         const ISoundTriggerHw::RecognitionConfig* config);
 
-    static void convertSoundModelEventFromHal(ISoundTriggerHwCallback::ModelEvent* event,
-                                              const struct sound_trigger_model_event* halEvent);
-    static ISoundTriggerHwCallback::RecognitionEvent* convertRecognitionEventFromHal(
-        const struct sound_trigger_recognition_event* halEvent);
     static void convertPhraseRecognitionExtraFromHal(
         PhraseRecognitionExtra* extra,
         const struct sound_trigger_phrase_recognition_extra* halExtra);
 
-    int doLoadSoundModel(const ISoundTriggerHw::SoundModel& soundModel,
-                         const sp<ISoundTriggerHwCallback>& callback,
-                         ISoundTriggerHwCallback::CallbackCookie cookie, uint32_t* modelId);
-
-    virtual ~SoundTriggerHalImpl();
+    static void soundModelCallback(struct sound_trigger_model_event* halEvent, void* cookie);
+    static void recognitionCallback(struct sound_trigger_recognition_event* halEvent, void* cookie);
 
     const char* mModuleName;
     struct sound_trigger_hw_device* mHwDevice;
@@ -115,8 +173,6 @@
     Mutex mLock;
 };
 
-extern "C" ISoundTriggerHw* HIDL_FETCH_ISoundTriggerHw(const char* name);
-
 }  // namespace implementation
 }  // namespace V2_0
 }  // namespace soundtrigger