diff --git a/desmume/src/frontend/cocoa/cocoa_output.mm b/desmume/src/frontend/cocoa/cocoa_output.mm
index 19c63ad9f..baf2cc1fa 100644
--- a/desmume/src/frontend/cocoa/cocoa_output.mm
+++ b/desmume/src/frontend/cocoa/cocoa_output.mm
@@ -210,8 +210,6 @@
 		SPU_ChangeSoundCore(SNDCORE_DUMMY, 0);
 	}
 	
-	rwlockAudioEmulateCore = self.rwlockProducer;
-	
 	pthread_rwlock_unlock(self.rwlockProducer);
 	
 	// Force the volume back to it's original setting.
@@ -456,13 +454,6 @@
 	}
 }
 
-- (void) handleEmuFrameProcessed
-{
-	SPU_Emulate_user();
-	
-	[super handleEmuFrameProcessed];
-}
-
 - (void) handleSetVolume:(NSData *)volumeData
 {
 	const float vol = *(float *)[volumeData bytes];
diff --git a/desmume/src/frontend/cocoa/openemu/OESoundInterface.mm b/desmume/src/frontend/cocoa/openemu/OESoundInterface.mm
index 5bed65d27..aac425e04 100644
--- a/desmume/src/frontend/cocoa/openemu/OESoundInterface.mm
+++ b/desmume/src/frontend/cocoa/openemu/OESoundInterface.mm
@@ -22,8 +22,6 @@
 
 
 OERingBuffer *openEmuSoundInterfaceBuffer = nil;
-static pthread_mutex_t *mutexAudioSampleReadWrite = NULL;
-pthread_rwlock_t *rwlockAudioEmulateCore = NULL;
 
 // Sound interface to the SPU
 SoundInterface_struct SNDOpenEmu = {
@@ -37,8 +35,8 @@ SoundInterface_struct SNDOpenEmu = {
 	SNDOpenEmuUnMuteAudio,
 	SNDOpenEmuSetVolume,
 	SNDOpenEmuClearBuffer,
-	SNDOpenEmuFetchSamples,
-	SNDOpenEmuPostProcessSamples
+	NULL,
+	NULL
 };
 
 SoundInterface_struct *SNDCoreList[] = {
@@ -51,23 +49,12 @@ int SNDOpenEmuInit(int buffer_size)
 {
 	[openEmuSoundInterfaceBuffer setLength:buffer_size * 4 / SPU_SAMPLE_SIZE];
 	
-	if (mutexAudioSampleReadWrite == NULL)
-	{
-		mutexAudioSampleReadWrite = (pthread_mutex_t *)malloc(sizeof(pthread_mutex_t));
-		pthread_mutex_init(mutexAudioSampleReadWrite, NULL);
-	}
-	
 	return 0;
 }
 
 void SNDOpenEmuDeInit()
 {
-	if (mutexAudioSampleReadWrite != NULL)
-	{
-		pthread_mutex_destroy(mutexAudioSampleReadWrite);
-		free(mutexAudioSampleReadWrite);
-		mutexAudioSampleReadWrite = NULL;
-	}
+	// Do nothing.
 }
 
 int SNDOpenEmuReset()
@@ -109,46 +96,3 @@ void SNDOpenEmuClearBuffer()
 {
 	// Do nothing. The OpenEmu frontend will take care of this.
 }
-
-void SNDOpenEmuFetchSamples(s16 *sampleBuffer, size_t sampleCount, ESynchMode synchMode, ISynchronizingAudioBuffer *theSynchronizer)
-{
-	if (mutexAudioSampleReadWrite == NULL)
-	{
-		return;
-	}
-	
-	pthread_mutex_lock(mutexAudioSampleReadWrite);
-	SPU_DefaultFetchSamples(sampleBuffer, sampleCount, synchMode, theSynchronizer);
-	pthread_mutex_unlock(mutexAudioSampleReadWrite);
-}
-
-size_t SNDOpenEmuPostProcessSamples(s16 *postProcessBuffer, size_t requestedSampleCount, ESynchMode synchMode, ISynchronizingAudioBuffer *theSynchronizer)
-{
-	size_t processedSampleCount = 0;
-	
-	switch (synchMode)
-	{
-		case ESynchMode_DualSynchAsynch:
-			if (rwlockAudioEmulateCore != NULL)
-			{
-				pthread_rwlock_wrlock(rwlockAudioEmulateCore);
-				processedSampleCount = SPU_DefaultPostProcessSamples(postProcessBuffer, requestedSampleCount, synchMode, theSynchronizer);
-				pthread_rwlock_unlock(rwlockAudioEmulateCore);
-			}
-			break;
-			
-		case ESynchMode_Synchronous:
-			if (mutexAudioSampleReadWrite != NULL)
-			{
-				pthread_mutex_lock(mutexAudioSampleReadWrite);
-				processedSampleCount = SPU_DefaultPostProcessSamples(postProcessBuffer, requestedSampleCount, synchMode, theSynchronizer);
-				pthread_mutex_unlock(mutexAudioSampleReadWrite);
-			}
-			break;
-			
-		default:
-			break;
-	}
-	
-	return processedSampleCount;
-}
diff --git a/desmume/src/frontend/cocoa/sndOSX.cpp b/desmume/src/frontend/cocoa/sndOSX.cpp
index 7f6a8bc5f..dd7ce5f5c 100644
--- a/desmume/src/frontend/cocoa/sndOSX.cpp
+++ b/desmume/src/frontend/cocoa/sndOSX.cpp
@@ -24,8 +24,6 @@
 
 // Global sound playback manager
 static CoreAudioOutput *coreAudioPlaybackManager = NULL;
-static pthread_mutex_t *mutexAudioSampleReadWrite = NULL;
-pthread_rwlock_t *rwlockAudioEmulateCore = NULL;
 
 // Sound interface to the SPU
 SoundInterface_struct SNDOSX = {
@@ -39,8 +37,8 @@ SoundInterface_struct SNDOSX = {
 	SNDOSXUnMuteAudio,
 	SNDOSXSetVolume,
 	SNDOSXClearBuffer,
-	SNDOSXFetchSamples,
-	SNDOSXPostProcessSamples
+	NULL,
+	NULL
 };
 
 SoundInterface_struct *SNDCoreList[] = {
@@ -55,12 +53,6 @@ int SNDOSXInit(int buffer_size)
 	coreAudioPlaybackManager = new CoreAudioOutput(buffer_size * 4 / SPU_SAMPLE_SIZE, SPU_SAMPLE_SIZE);
 	delete oldcoreAudioPlaybackManager;
 	
-	if (mutexAudioSampleReadWrite == NULL)
-	{
-		mutexAudioSampleReadWrite = (pthread_mutex_t *)malloc(sizeof(pthread_mutex_t));
-		pthread_mutex_init(mutexAudioSampleReadWrite, NULL);
-	}
-	
 	coreAudioPlaybackManager->start();
 	coreAudioPlaybackManager->pause();
 	
@@ -71,13 +63,6 @@ void SNDOSXDeInit()
 {
 	delete coreAudioPlaybackManager;
 	coreAudioPlaybackManager = NULL;
-	
-	if (mutexAudioSampleReadWrite != NULL)
-	{
-		pthread_mutex_destroy(mutexAudioSampleReadWrite);
-		free(mutexAudioSampleReadWrite);
-		mutexAudioSampleReadWrite = NULL;
-	}
 }
 
 int SNDOSXReset()
@@ -177,46 +162,3 @@ void SNDOSXClearBuffer()
 	
 	coreAudioPlaybackManager->clearBuffer();
 }
-
-void SNDOSXFetchSamples(s16 *sampleBuffer, size_t sampleCount, ESynchMode synchMode, ISynchronizingAudioBuffer *theSynchronizer)
-{
-	if (mutexAudioSampleReadWrite == NULL)
-	{
-		return;
-	}
-	
-	pthread_mutex_lock(mutexAudioSampleReadWrite);
-	SPU_DefaultFetchSamples(sampleBuffer, sampleCount, synchMode, theSynchronizer);
-	pthread_mutex_unlock(mutexAudioSampleReadWrite);
-}
-
-size_t SNDOSXPostProcessSamples(s16 *postProcessBuffer, size_t requestedSampleCount, ESynchMode synchMode, ISynchronizingAudioBuffer *theSynchronizer)
-{
-	size_t processedSampleCount = 0;
-	
-	switch (synchMode)
-	{
-		case ESynchMode_DualSynchAsynch:
-			if (rwlockAudioEmulateCore != NULL)
-			{
-				pthread_rwlock_wrlock(rwlockAudioEmulateCore);
-				processedSampleCount = SPU_DefaultPostProcessSamples(postProcessBuffer, requestedSampleCount, synchMode, theSynchronizer);
-				pthread_rwlock_unlock(rwlockAudioEmulateCore);
-			}
-			break;
-			
-		case ESynchMode_Synchronous:
-			if (mutexAudioSampleReadWrite != NULL)
-			{
-				pthread_mutex_lock(mutexAudioSampleReadWrite);
-				processedSampleCount = SPU_DefaultPostProcessSamples(postProcessBuffer, requestedSampleCount, synchMode, theSynchronizer);
-				pthread_mutex_unlock(mutexAudioSampleReadWrite);
-			}
-			break;
-			
-		default:
-			break;
-	}
-	
-	return processedSampleCount;
-}
diff --git a/desmume/src/frontend/cocoa/sndOSX.h b/desmume/src/frontend/cocoa/sndOSX.h
index e109d7ebb..42aafd735 100644
--- a/desmume/src/frontend/cocoa/sndOSX.h
+++ b/desmume/src/frontend/cocoa/sndOSX.h
@@ -26,7 +26,6 @@
 #define SNDCORE_OSX 58325 //hopefully this is unique number
 
 extern SoundInterface_struct SNDOSX; // Sound interface to the SPU
-extern pthread_rwlock_t *rwlockAudioEmulateCore; // RWlock for the emulation core - used when mixing audio in Dual Synch/Asynch mode in post-process
 
 // Core Audio functions for the sound interface
 int		SNDOSXInit(int buffer_size);
@@ -40,7 +39,5 @@ void	SNDOSXPauseAudio();
 void	SNDOSXUnpauseAudio();
 void	SNDOSXSetVolume(int volume);
 void	SNDOSXClearBuffer();
-void	SNDOSXFetchSamples(s16 *sampleBuffer, size_t sampleCount, ESynchMode synchMode, ISynchronizingAudioBuffer *theSynchronizer);
-size_t	SNDOSXPostProcessSamples(s16 *postProcessBuffer, size_t requestedSampleCount, ESynchMode synchMode, ISynchronizingAudioBuffer *theSynchronizer);
 
 #endif // _OSXSOUNDINTERFACE_