diff --git a/DStarControl.cpp b/DStarControl.cpp
index e8d7035..8cd57e5 100644
--- a/DStarControl.cpp
+++ b/DStarControl.cpp
@@ -23,6 +23,7 @@
 #include <functional>
 
 const unsigned int MAX_SYNC_BIT_ERRORS = 2U;
+const unsigned int FAST_DATA_BEEP_GRACE_FRAMES = 6U;
 
 bool CallsignCompare(const std::string& arg, const unsigned char* my)
 {
@@ -83,7 +84,15 @@ m_minRSSI(0U),
 m_aveRSSI(0U),
 m_rssiCount(0U),
 m_enabled(true),
-m_fp(NULL)
+m_fp(NULL),
+m_rfVoiceSyncData(NULL),
+m_rfVoiceSyncDataLen(0U),
+m_netVoiceSyncData(NULL),
+m_netVoiceSyncDataLen(0U),
+m_rfNextFrameIsFastData(false),
+m_netNextFrameIsFastData(false),
+m_rfSkipDTMFBlankingFrames(0U),
+m_netSkipDTMFBlankingFrames(0U)
 {
 	assert(display != NULL);
 	assert(rssiMapper != NULL);
@@ -92,6 +101,8 @@ m_fp(NULL)
 	m_gateway  = new unsigned char[DSTAR_LONG_CALLSIGN_LENGTH];
 
 	m_lastFrame = new unsigned char[DSTAR_FRAME_LENGTH_BYTES + 1U];
+	m_rfVoiceSyncData = new unsigned char[MODEM_DATA_LEN];
+	m_netVoiceSyncData = new unsigned char[MODEM_DATA_LEN];
 
 	std::string call = callsign;
 	call.resize(DSTAR_LONG_CALLSIGN_LENGTH - 1U, ' ');
@@ -116,6 +127,56 @@ CDStarControl::~CDStarControl()
 	delete[] m_callsign;
 	delete[] m_gateway;
 	delete[] m_lastFrame;
+	delete[] m_rfVoiceSyncData;
+	delete[] m_netVoiceSyncData;
+}
+
+unsigned int CDStarControl::maybeFixupVoiceFrame(
+	unsigned char*  data,
+	unsigned int    len,
+	unsigned int    offset,
+	const char*     log_prefix,
+	unsigned char   n,
+	bool            blank_dtmf,
+	unsigned char*  voice_sync_data,
+	unsigned int*   voice_sync_data_len,
+	bool*           next_frame_is_fast_data,
+	unsigned int*   skip_dtmf_blanking_frames
+	)
+{
+	unsigned int errors = 0U;
+	unsigned char mini_header = data[offset + 9U] ^ DSTAR_SCRAMBLER_BYTES[0U];
+	unsigned char mini_header_type = mini_header & DSTAR_SLOW_DATA_TYPE_MASK;
+
+	if (n == 0U) {
+		LogMessage("%s frame %u: FEC regeneration disabled for first frame", log_prefix, n);
+	} else if ((n % 2U != 0U) &&
+		   ((mini_header_type == DSTAR_SLOW_DATA_TYPE_FASTDATA01) ||
+		    (mini_header_type == DSTAR_SLOW_DATA_TYPE_FASTDATA16))) {
+		*next_frame_is_fast_data = true;
+		if (blank_dtmf)
+			*skip_dtmf_blanking_frames = FAST_DATA_BEEP_GRACE_FRAMES;
+		LogMessage("%s frame %u: found fast data", log_prefix, n);
+	} else if (*next_frame_is_fast_data == true) {
+		*next_frame_is_fast_data = false;
+		if (blank_dtmf)
+			*skip_dtmf_blanking_frames = FAST_DATA_BEEP_GRACE_FRAMES;
+		LogMessage("%s frame %u: found fast data (cont.)", log_prefix, n);
+	} else {
+		errors = m_fec.regenerateDStar(data + offset);
+		LogMessage("%s frame %u: *** REGENERATING FEC ***", log_prefix, n);
+
+		if (blank_dtmf && (*skip_dtmf_blanking_frames > 0U)) {
+			(*skip_dtmf_blanking_frames)--;
+			LogMessage("%s frame %u: *** Not BLANKING DTMF (left to skip: %u) ***",
+				   log_prefix, n, *skip_dtmf_blanking_frames);
+		} else if (blank_dtmf && (*skip_dtmf_blanking_frames == 0U)) {
+			LogMessage("%s frame %u: *** BLANKING DTMF ***", log_prefix, n);
+			blankDTMF(data + offset);
+		}
+	}
+
+	return errors;
 }
 
 bool CDStarControl::writeModem(unsigned char *data, unsigned int len)
@@ -323,6 +384,9 @@ bool CDStarControl::writeModem(unsigned char *data, unsigned int len)
 			if (m_duplex)
 				writeQueueEOTRF();
 
+			m_rfNextFrameIsFastData = false;
+			m_rfSkipDTMFBlankingFrames = 0U;
+
 			unsigned char my1[DSTAR_LONG_CALLSIGN_LENGTH];
 			unsigned char my2[DSTAR_SHORT_CALLSIGN_LENGTH];
 			unsigned char your[DSTAR_LONG_CALLSIGN_LENGTH];
@@ -353,17 +417,6 @@ bool CDStarControl::writeModem(unsigned char *data, unsigned int len)
 
 			return false;
 		} else if (m_rfState == RS_RF_AUDIO) {
-			unsigned int errors = 0U;
-			if (!m_rfHeader.isDataPacket()) {
-				errors = m_fec.regenerateDStar(data + 1U);
-				m_display->writeDStarBER(float(errors) / 0.48F);
-				LogDebug("D-Star, audio sequence no. %u, errs: %u/48 (%.1f%%)", m_rfN, errors, float(errors) / 0.48F);
-				m_rfErrs += errors;
-			}
-
-			m_rfBits += 48U;
-			m_rfFrames++;
-
 			// The sync is regenerated by the modem so can do exact match
 			if (::memcmp(data + 1U + DSTAR_VOICE_FRAME_LENGTH_BYTES, DSTAR_SYNC_BYTES, DSTAR_DATA_FRAME_LENGTH_BYTES) == 0)
 				m_rfN = 0U;
@@ -374,13 +427,23 @@ bool CDStarControl::writeModem(unsigned char *data, unsigned int len)
 				m_display->writeDStarRSSI(m_rssi);
 			}
 
+			unsigned int errors = 0U;
+			if (!m_rfHeader.isDataPacket()) {
+				errors = maybeFixupVoiceFrame(data, len, 1U, "RF", m_rfN, m_duplex, m_rfVoiceSyncData, &m_rfVoiceSyncDataLen,
+							      &m_rfNextFrameIsFastData, &m_rfSkipDTMFBlankingFrames);
+				m_display->writeDStarBER(float(errors) / 0.48F);
+				LogDebug("D-Star, audio sequence no. %u, errs: %u/48 (%.1f%%)", m_rfN, errors, float(errors) / 0.48F);
+				m_rfErrs += errors;
+			}
+
+			m_rfBits += 48U;
+			m_rfFrames++;
+
 			if (m_net)
 				writeNetworkDataRF(data, errors, false);
 
-			if (m_duplex) {
-				blankDTMF(data + 1U);
+			if (m_duplex)
 				writeQueueDataRF(data);
-			}
 
 			m_rfN = (m_rfN + 1U) % 21U;
 		} else if (m_rfState == RS_RF_LATE_ENTRY) {
@@ -492,7 +555,8 @@ bool CDStarControl::writeModem(unsigned char *data, unsigned int len)
 
 			unsigned int errors = 0U;
 			if (!m_rfHeader.isDataPacket()) {
-				errors = m_fec.regenerateDStar(data + 1U);
+				errors = maybeFixupVoiceFrame(data, len, 1U, "RF", m_rfN, m_duplex, m_rfVoiceSyncData, &m_rfVoiceSyncDataLen,
+							       &m_rfNextFrameIsFastData, &m_rfSkipDTMFBlankingFrames);
 				LogDebug("D-Star, audio sequence no. %u, errs: %u/48 (%.1f%%)", m_rfN, errors, float(errors) / 0.48F);
 				m_rfErrs += errors;
 			}
@@ -502,10 +566,8 @@ bool CDStarControl::writeModem(unsigned char *data, unsigned int len)
 			if (m_net)
 				writeNetworkDataRF(data, errors, false);
 
-			if (m_duplex) {
-				blankDTMF(data + 1U);
+			if (m_duplex)
 				writeQueueDataRF(data);
-			}
 
 			m_rfState = RS_RF_AUDIO;
 
@@ -670,6 +732,9 @@ void CDStarControl::writeNetwork()
 		writeFile(data + 1U, length - 1U);
 		closeFile();
 #endif
+		m_netNextFrameIsFastData = false;
+		m_netSkipDTMFBlankingFrames = 0U;
+
 		unsigned char my1[DSTAR_LONG_CALLSIGN_LENGTH];
 		unsigned char my2[DSTAR_SHORT_CALLSIGN_LENGTH];
 		unsigned char your[DSTAR_LONG_CALLSIGN_LENGTH];
@@ -690,9 +755,8 @@ void CDStarControl::writeNetwork()
 
 		unsigned int errors = 0U;
 		if (!m_netHeader.isDataPacket())
-			errors = m_fec.regenerateDStar(data + 2U);
-
-		blankDTMF(data + 2U);
+			errors = maybeFixupVoiceFrame(data, length, 2U, "Net", n, true, m_netVoiceSyncData, &m_netVoiceSyncDataLen,
+						      &m_netNextFrameIsFastData, &m_netSkipDTMFBlankingFrames);
 
 		data[1U] = TAG_DATA;
 
diff --git a/DStarControl.h b/DStarControl.h
index 3d541d1..1378c87 100644
--- a/DStarControl.h
+++ b/DStarControl.h
@@ -98,6 +98,28 @@ private:
 	unsigned int               m_rssiCount;
 	bool                       m_enabled;
 	FILE*                      m_fp;
+	unsigned char*             m_rfVoiceSyncData;
+	unsigned int               m_rfVoiceSyncDataLen;
+	unsigned char*             m_netVoiceSyncData;
+	unsigned int               m_netVoiceSyncDataLen;
+	bool                       m_rfNextFrameIsFastData;
+	bool                       m_netNextFrameIsFastData;
+	unsigned int               m_rfSkipDTMFBlankingFrames;
+	unsigned int               m_netSkipDTMFBlankingFrames;
+
+
+	unsigned int maybeFixupVoiceFrame(
+		unsigned char*  data,
+		unsigned int    len,
+		unsigned int    offset,
+		const char*     log_prefix,
+		unsigned char   n,
+		bool            blank_dtmf,
+		unsigned char*  voice_sync_data,
+		unsigned int*   voice_sync_data_len,
+		bool*           next_frame_is_fast_data,
+		unsigned int*   skip_dtmf_blanking_frames
+		);
 
 	void writeNetwork();
 
diff --git a/DStarDefines.h b/DStarDefines.h
index 8c28991..46f4c1d 100644
--- a/DStarDefines.h
+++ b/DStarDefines.h
@@ -42,12 +42,14 @@ const unsigned int  DSTAR_DATA_FRAME_LENGTH_BYTES  = 3U;
 const unsigned int  DSTAR_LONG_CALLSIGN_LENGTH  = 8U;
 const unsigned int  DSTAR_SHORT_CALLSIGN_LENGTH = 4U;
 
-const unsigned char DSTAR_SLOW_DATA_TYPE_MASK    = 0xF0U;
-const unsigned char DSTAR_SLOW_DATA_TYPE_GPSDATA = 0x30U;
-const unsigned char DSTAR_SLOW_DATA_TYPE_TEXT    = 0x40U;
-const unsigned char DSTAR_SLOW_DATA_TYPE_HEADER  = 0x50U;
-const unsigned char DSTAR_SLOW_DATA_TYPE_SQUELCH = 0xC0U;
-const unsigned char DSTAR_SLOW_DATA_LENGTH_MASK  = 0x0FU;
+const unsigned char DSTAR_SLOW_DATA_TYPE_MASK       = 0xF0U;
+const unsigned char DSTAR_SLOW_DATA_TYPE_GPSDATA    = 0x30U;
+const unsigned char DSTAR_SLOW_DATA_TYPE_TEXT       = 0x40U;
+const unsigned char DSTAR_SLOW_DATA_TYPE_HEADER     = 0x50U;
+const unsigned char DSTAR_SLOW_DATA_TYPE_FASTDATA01 = 0x80U;
+const unsigned char DSTAR_SLOW_DATA_TYPE_FASTDATA16 = 0x90U;
+const unsigned char DSTAR_SLOW_DATA_TYPE_SQUELCH    = 0xC0U;
+const unsigned char DSTAR_SLOW_DATA_LENGTH_MASK     = 0x0FU;
 
 // Data Frames are always scrambled using the first three bytes of
 // DSTAR_SCRAMBLER_BYTES, and Voice Frames are scrambled with all nine
diff --git a/Defines.h b/Defines.h
index 8c57721..ebd75eb 100644
--- a/Defines.h
+++ b/Defines.h
@@ -39,6 +39,8 @@ const unsigned char TAG_DATA   = 0x01U;
 const unsigned char TAG_LOST   = 0x02U;
 const unsigned char TAG_EOT    = 0x03U;
 
+const unsigned int  MODEM_DATA_LEN = 220U;
+
 enum HW_TYPE {
 	HWT_MMDVM,
 	HWT_DVMEGA,
diff --git a/MMDVMHost.cpp b/MMDVMHost.cpp
index 333b701..f100634 100644
--- a/MMDVMHost.cpp
+++ b/MMDVMHost.cpp
@@ -668,7 +668,7 @@ int CMMDVMHost::run()
 			m_ump->setCD(cd);
 		}
 
-		unsigned char data[220U];
+		unsigned char data[MODEM_DATA_LEN];
 		unsigned int len;
 		bool ret;