diff --git a/radio/src/audio_arm.cpp b/radio/src/audio_arm.cpp
index 5d2fb1be9..ea4af817c 100644
--- a/radio/src/audio_arm.cpp
+++ b/radio/src/audio_arm.cpp
@@ -117,132 +117,190 @@ const char * audioFilenames[] = {
 };
 
 uint64_t sdAvailableSystemAudioFiles = 0;
-uint8_t  sdAvailablePhaseAudioFiles[MAX_PHASES] = { 0 };
-uint8_t  sdAvailableMixerAudioFiles[MAX_MIXERS] = { 0 };
+uint32_t sdAvailablePhaseAudioFiles = 0;
+uint32_t sdAvailableSwitchAudioFiles = 0;
+uint64_t sdAvailableLogicalSwitchAudioFiles = 0;
 
-void refreshSystemAudioFiles()
+#define MASK_SYSTEM_AUDIO_FILE(index)                 ((uint64_t)1 << index)
+#define MASK_PHASE_AUDIO_FILE(index, event)           ((uint32_t)1 << (2*index+event))
+#define MASK_SWITCH_AUDIO_FILE(index)                 ((uint32_t)1 << index)
+#define MASK_LOGICAL_SWITCH_AUDIO_FILE(index, event)  ((uint64_t)1 << (2*index+event))
+
+bool isFileAvailable(const char * filename)
 {
   FILINFO info;
-#if _USE_LFN
   TCHAR lfn[_MAX_LFN + 1];
   info.lfname = lfn;
   info.lfsize = sizeof(lfn);
-#endif
+  return f_stat(filename, &info) == FR_OK;
+}
 
-  char filename[32] = SYSTEM_SOUNDS_PATH "/";
+void getSystemAudioFile(char * filename, int index)
+{
+  strcpy(filename, SYSTEM_SOUNDS_PATH "/");
   strncpy(filename+SOUNDS_PATH_LNG_OFS, currentLanguagePack->id, 2);
+  strcpy(filename+sizeof(SYSTEM_SOUNDS_PATH), audioFilenames[index]);
+  strcat(filename+sizeof(SYSTEM_SOUNDS_PATH), SOUNDS_EXT);
+}
+
+void referenceSystemAudioFiles()
+{
+  char filename[AUDIO_FILENAME_MAXLEN+1];
+  uint64_t availableAudioFiles = 0;
 
   assert(sizeof(audioFilenames)==AU_FRSKY_FIRST*sizeof(char *));
   assert(sizeof(sdAvailableSystemAudioFiles)*8 >= AU_FRSKY_FIRST);
 
-  uint64_t availableAudioFiles = 0;
-
-  for (uint32_t i=0; i<AU_FRSKY_FIRST; i++) {
-    strcpy(filename+sizeof(SYSTEM_SOUNDS_PATH), audioFilenames[i]);
-    strcat(filename+sizeof(SYSTEM_SOUNDS_PATH), SOUNDS_EXT);
-    if (f_stat(filename, &info) == FR_OK)
-      availableAudioFiles |= ((uint64_t)1 << i);
+  for (int i=0; i<AU_FRSKY_FIRST; i++) {
+    getSystemAudioFile(filename, i);
+    if (isFileAvailable(filename)) {
+      availableAudioFiles |= MASK_SYSTEM_AUDIO_FILE(i);
+    }
   }
 
   sdAvailableSystemAudioFiles = availableAudioFiles;
 }
 
-const char * suffixes[] = { "-OFF", "-ON", /*"-BG", */NULL };
+const char * suffixes[] = { "-off", "-on" };
 
-inline uint8_t getAvailableFiles(char *prefix, FILINFO &info, char *filename)
+void getPhaseAudioFile(char * filename, int index, unsigned int event)
 {
-  uint8_t result = 0;
-
-  for (uint8_t i=0; suffixes[i]; i++) {
-    strcpy(prefix, suffixes[i]);
-    strcat(prefix, SOUNDS_EXT);
-    if (f_stat(filename, &info) == FR_OK)
-      result |= ((uint8_t)1 << i);
-  }
-
-  return result;
-}
-
-void refreshModelAudioFiles()
-{
-  FILINFO info;
-  TCHAR lfn[_MAX_LFN + 1];
-  info.lfname = lfn;
-  info.lfsize = sizeof(lfn);
-
-  char filename[AUDIO_FILENAME_MAXLEN+1] = SOUNDS_PATH "/";
+  strcpy(filename, SOUNDS_PATH "/");
   strncpy(filename+SOUNDS_PATH_LNG_OFS, currentLanguagePack->id, 2);
-  
-  if (sdMounted()) {
-    char *buf = strcat_modelname(&filename[sizeof(SOUNDS_PATH)], g_eeGeneral.currModel);
-    *buf++ = '/';
+  char *str = strcat_modelname(filename+sizeof(SOUNDS_PATH), g_eeGeneral.currModel);
+  *str++ = '/';
+  char * tmp = strcat_phasename(str, index);
+  strcpy(tmp, suffixes[event]);
+  strcat(tmp, SOUNDS_EXT);
+}
 
-    for (uint32_t i=0; i<MAX_PHASES; i++) {
-      char *tmp = strcat_phasename(buf, i);
-      sdAvailablePhaseAudioFiles[i] = (tmp != buf ? getAvailableFiles(strcat_phasename(buf, i), info, filename) : 0);
+void getSwitchAudioFile(char * filename, int index)
+{
+  strcpy(filename, SOUNDS_PATH "/");
+  strncpy(filename+SOUNDS_PATH_LNG_OFS, currentLanguagePack->id, 2);
+  char *str = strcat_modelname(filename+sizeof(SOUNDS_PATH), g_eeGeneral.currModel);
+  *str++ = '/';
+  int len = STR_VSWITCHES[0];
+  strncpy(str, &STR_VSWITCHES[1+len*index], len);
+  str += len-1;
+  if (*str == '\300') {
+    strcpy(str, "-up");
+    str += 3;
+  }
+  else if (*str == '-') {
+    strcpy(str, "-mid");
+    str += 4;
+  }
+  else if (*str == '\301') {
+    strcpy(str, "-down");
+    str += 5;
+  }
+  else {
+    str += 1;
+  }
+  strcat(str, SOUNDS_EXT);
+}
+
+void getLogicalSwitchAudioFile(char * filename, int index, unsigned int event)
+{
+  strcpy(filename, SOUNDS_PATH "/");
+  strncpy(filename+SOUNDS_PATH_LNG_OFS, currentLanguagePack->id, 2);
+  char *str = strcat_modelname(filename+sizeof(SOUNDS_PATH), g_eeGeneral.currModel);
+  *str++ = '/';
+  int len = STR_VSWITCHES[0];
+  strncpy(str, &STR_VSWITCHES[1+len*(index+SWSRC_FIRST_CSW-1)], len);
+  str += len;
+  strcpy(str, suffixes[event]);
+  strcat(str, SOUNDS_EXT);
+}
+
+void referenceModelAudioFiles()
+{
+  char filename[AUDIO_FILENAME_MAXLEN+1];
+
+  {
+    // Phases Audio Files <phasename>-[on|off].wav
+    uint32_t mask = 0;
+    for (int i=0; i<MAX_PHASES; i++) {
+      for (int event=0; event<2; event++) {
+        getPhaseAudioFile(filename, i, event);
+        if (isFileAvailable(filename)) {
+          mask |= MASK_PHASE_AUDIO_FILE(i, event);
+        }
+      }
     }
+    sdAvailablePhaseAudioFiles = mask;
+  }
 
-    /* for (uint32_t i=0; i<MAX_MIXERS; i++) {
-      char *tmp = strcat_mixername_nodefault(buf, i);
-      sdAvailableMixerAudioFiles[i] = (tmp != buf ? getAvailableFiles(tmp, info, filename) : 0);
-    } */
+  {
+    // Switches Audio Files <switchname>-[up|mid|down].wav
+    uint32_t mask = 0;
+    for (int i=0; i<SWSRC_LAST_SWITCH+NUM_XPOTS*POTS_POS_COUNT; i++) {
+      getSwitchAudioFile(filename, i);
+      if (isFileAvailable(filename)) {
+        mask |= MASK_SWITCH_AUDIO_FILE(i);
+      }
+    }
+    sdAvailableSwitchAudioFiles = mask;
+  }
+
+  {
+    // Logical Switches Audio Files <switchname>-[on|off].wav
+    uint64_t mask = 0;
+    for (int i=0; i<NUM_CSW; i++) {
+      for (int event=0; event<2; event++) {
+        getLogicalSwitchAudioFile(filename, i, event);
+        if (isFileAvailable(filename)) {
+          mask |= MASK_LOGICAL_SWITCH_AUDIO_FILE(i, event);
+        }
+      }
+    }
+    sdAvailableLogicalSwitchAudioFiles = mask;
   }
 }
 
-bool isAudioFileAvailable(uint32_t i, char * filename)
+bool isAudioFileReferenced(uint32_t i, char * filename)
 {
   uint8_t category = (i >> 24);
   uint8_t index = (i >> 16) & 0xFF;
   uint8_t event = i & 0xFF;
 
 #if 0
-  printf("isAudioFileAvailable(%08x)\n", i); fflush(stdout);
+  printf("isAudioFileReferenced(%08x)\n", i); fflush(stdout);
 #endif
 
   if (category == SYSTEM_AUDIO_CATEGORY) {
-    if (sdAvailableSystemAudioFiles & ((uint64_t)1 << event)) {
-      strcpy(filename, SYSTEM_SOUNDS_PATH "/");
-      strncpy(filename+SOUNDS_PATH_LNG_OFS, currentLanguagePack->id, 2);
-      strcpy(filename+sizeof(SYSTEM_SOUNDS_PATH), audioFilenames[i]);
-      strcat(filename+sizeof(SYSTEM_SOUNDS_PATH), SOUNDS_EXT);
+    if (sdAvailableSystemAudioFiles & MASK_SYSTEM_AUDIO_FILE(index)) {
+      getSystemAudioFile(filename, index);
       return true;
     }
   }
   else if (category == PHASE_AUDIO_CATEGORY) {
-    if (sdAvailablePhaseAudioFiles[index] & ((uint32_t)1 << event)) {
-      strcpy(filename, SOUNDS_PATH "/");
-      strncpy(filename+SOUNDS_PATH_LNG_OFS, currentLanguagePack->id, 2);
-      char *str = strcat_modelname(filename+sizeof(SOUNDS_PATH), g_eeGeneral.currModel);
-      *str++ = '/';
-      char * tmp = strcat_phasename(str, index);
-      if (tmp != str) {
-        strcpy(tmp, suffixes[event]);
-        strcat(tmp, SOUNDS_EXT);
-        return true;
-      }
+    if (sdAvailablePhaseAudioFiles & MASK_PHASE_AUDIO_FILE(index, event)) {
+      getPhaseAudioFile(filename, index, event);
+      return true;
     }
   }
-  else if (category == MIXER_AUDIO_CATEGORY) {
-    if (sdAvailableMixerAudioFiles[index] & ((uint32_t)1 << event)) {
-      strcpy(filename, SOUNDS_PATH "/");
-      strncpy(filename+SOUNDS_PATH_LNG_OFS, currentLanguagePack->id, 2);
-      char *str = strcat_modelname(filename+sizeof(SOUNDS_PATH), g_eeGeneral.currModel);
-      *str++ = '/';
-      char * tmp = strcat_mixername(str, index);
-      if (tmp != str) {
-        strcpy(tmp, suffixes[event]);
-        strcat(tmp, SOUNDS_EXT);
-        return true;
-      }
+  else if (category == SWITCH_AUDIO_CATEGORY) {
+    if (sdAvailableSwitchAudioFiles & MASK_SWITCH_AUDIO_FILE(index)) {
+      getSwitchAudioFile(filename, index);
+      return true;
+    }
+  }
+  else if (category == LOGICAL_SWITCH_AUDIO_CATEGORY) {
+    if (sdAvailableLogicalSwitchAudioFiles & MASK_LOGICAL_SWITCH_AUDIO_FILE(index, event)) {
+      getLogicalSwitchAudioFile(filename, index, event);
+      return true;
     }
   }
 
   return false;
 }
 #else
-#define isAudioFileAvailable(i, f) false
+#define isAudioFileReferenced(i, f) false
 #endif
 
+// TODO should be generated and in flash rather than in ram
 int16_t alawTable[256];
 int16_t ulawTable[256];
 
@@ -757,10 +815,6 @@ void AudioQueue::reset()
 
 void audioEvent(uint8_t e, uint16_t f)
 {
-#if defined(SDCARD)
-  char filename[AUDIO_FILENAME_MAXLEN+1];
-#endif
-
 #if defined(HAPTIC)
   haptic.event(e); //do this before audio to help sync timings
 #endif
@@ -773,7 +827,8 @@ void audioEvent(uint8_t e, uint16_t f)
 
   if (g_eeGeneral.beepMode>0 || (g_eeGeneral.beepMode==0 && e>=AU_TRIM_MOVE) || (g_eeGeneral.beepMode>=-1 && e<=AU_ERROR)) {
 #if defined(SDCARD)
-    if (e < AU_FRSKY_FIRST && isAudioFileAvailable(e, filename)) {
+    char filename[AUDIO_FILENAME_MAXLEN+1];
+    if (e < AU_FRSKY_FIRST && isAudioFileReferenced(e, filename)) {
       audioQueue.playFile(filename);
     }
     else
diff --git a/radio/src/audio_arm.h b/radio/src/audio_arm.h
index 9b45187b0..b96808426 100644
--- a/radio/src/audio_arm.h
+++ b/radio/src/audio_arm.h
@@ -277,16 +277,21 @@ void audioStart();
 
 #define AUDIO_HEARTBEAT()
 
-#define SYSTEM_AUDIO_CATEGORY 0
-#define MODEL_AUDIO_CATEGORY  1
-#define PHASE_AUDIO_CATEGORY  2
-#define MIXER_AUDIO_CATEGORY  3
+enum AutomaticPromptsCategories {
+  SYSTEM_AUDIO_CATEGORY,
+  MODEL_AUDIO_CATEGORY,
+  PHASE_AUDIO_CATEGORY,
+  SWITCH_AUDIO_CATEGORY,
+  LOGICAL_SWITCH_AUDIO_CATEGORY,
+};
 
-#define AUDIO_EVENT_OFF       0
-#define AUDIO_EVENT_ON        1
-#define AUDIO_EVENT_BG        2
+enum AutomaticPromptsEvents {
+  AUDIO_EVENT_OFF,
+  AUDIO_EVENT_ON,
+  AUDIO_EVENT_MID,
+};
 
-extern void pushPrompt(uint16_t prompt, uint8_t id=0);
+void pushPrompt(uint16_t prompt, uint8_t id=0);
 
 #define I18N_PLAY_FUNCTION(lng, x, ...) void lng ## _ ## x(__VA_ARGS__, uint8_t id)
 #define PLAY_FUNCTION(x, ...)    void x(__VA_ARGS__, uint8_t id)
@@ -300,15 +305,16 @@ extern void pushPrompt(uint16_t prompt, uint8_t id=0);
 #define AUDIO_RESET()            audioQueue.reset()
 
 #if defined(SDCARD)
-  #define PLAY_PHASE_OFF(phase) do { char filename[AUDIO_FILENAME_MAXLEN+1]; if (isAudioFileAvailable((PHASE_AUDIO_CATEGORY << 24) + (phase << 16) + AUDIO_EVENT_OFF, filename)) audioQueue.playFile(filename); } while (0)
-  #define PLAY_PHASE_ON(phase)  do { char filename[AUDIO_FILENAME_MAXLEN+1]; if (isAudioFileAvailable((PHASE_AUDIO_CATEGORY << 24) + (phase << 16) + AUDIO_EVENT_ON, filename)) audioQueue.playFile(filename); } while (0)
+  #define PLAY_PHASE_OFF(phase) do { char filename[AUDIO_FILENAME_MAXLEN+1]; if (isAudioFileReferenced((PHASE_AUDIO_CATEGORY << 24) + (phase << 16) + AUDIO_EVENT_OFF, filename)) audioQueue.playFile(filename); } while (0)
+  #define PLAY_PHASE_ON(phase)  do { char filename[AUDIO_FILENAME_MAXLEN+1]; if (isAudioFileReferenced((PHASE_AUDIO_CATEGORY << 24) + (phase << 16) + AUDIO_EVENT_ON, filename)) audioQueue.playFile(filename); } while (0)
 #else
   #define PLAY_PHASE_OFF(phase)
   #define PLAY_PHASE_ON(phase)
 #endif
 
-extern void refreshSystemAudioFiles();
-extern void refreshModelAudioFiles();
-extern bool isAudioFileAvailable(uint32_t i, char * filename);
+void referenceSystemAudioFiles();
+void referenceModelAudioFiles();
+
+bool isAudioFileReferenced(uint32_t i, char * filename/*at least AUDIO_FILENAME_MAXLEN+1 long*/);
 
 #endif
diff --git a/radio/src/eeprom_raw.cpp b/radio/src/eeprom_raw.cpp
index 718fe3558..5050f7cbb 100644
--- a/radio/src/eeprom_raw.cpp
+++ b/radio/src/eeprom_raw.cpp
@@ -404,7 +404,7 @@ void eeLoadModel(uint8_t id)
 #endif
 
 #if defined(CPUARM) && defined(SDCARD)
-    refreshModelAudioFiles();
+    referenceModelAudioFiles();
 #endif
 
     LOAD_MODEL_BITMAP();
diff --git a/radio/src/eeprom_rlc.cpp b/radio/src/eeprom_rlc.cpp
index f6f62502e..190dcdbe8 100644
--- a/radio/src/eeprom_rlc.cpp
+++ b/radio/src/eeprom_rlc.cpp
@@ -978,7 +978,7 @@ void eeLoadModel(uint8_t id)
 #endif
 
 #if defined(CPUARM) && defined(SDCARD)
-    refreshModelAudioFiles();
+    referenceModelAudioFiles();
 #endif
 
     LOAD_MODEL_BITMAP();
diff --git a/radio/src/opentx.h b/radio/src/opentx.h
index dcfed29a4..b6a555b11 100644
--- a/radio/src/opentx.h
+++ b/radio/src/opentx.h
@@ -1616,8 +1616,7 @@ uint8_t zlen(const char *str, uint8_t size);
 bool zexist(const char *str, uint8_t size);
 char * strcat_zchar(char * dest, char * name, uint8_t size, const char *defaultName, uint8_t defaultNameSize, uint8_t defaultIdx);
 #define strcat_modelname(dest, idx) strcat_zchar(dest, modelHeaders[idx].name, LEN_MODEL_NAME, STR_MODEL, PSIZE(TR_MODEL), idx+1)
-#define strcat_phasename(dest, idx) strcat_zchar(dest, g_model.phaseData[idx].name, LEN_FP_NAME, NULL, 0, 0)
-#define strcat_mixername(dest, idx) strcat_zchar(dest, g_model.mixData[idx].name, LEN_EXPOMIX_NAME, NULL, 0, 0)
+#define strcat_phasename(dest, idx) strcat_zchar(dest, g_model.phaseData[idx].name, LEN_FP_NAME, STR_FP, PSIZE(TR_FP), idx+1)
 #define ZLEN(s) zlen(s, sizeof(s))
 #define ZEXIST(s) zexist(s, sizeof(s))
 #endif
diff --git a/radio/src/simpgmspace.cpp b/radio/src/simpgmspace.cpp
index cd3fb4803..0b5deb589 100644
--- a/radio/src/simpgmspace.cpp
+++ b/radio/src/simpgmspace.cpp
@@ -300,7 +300,7 @@ void *main_thread(void *)
     eeReadAll(); // load general setup and selected model
 
 #if defined(CPUARM) && defined(SDCARD)
-    refreshSystemAudioFiles();
+    referenceSystemAudioFiles();
 #endif
 
     if (g_eeGeneral.backlightMode != e_backlight_mode_off) backlightOn(); // on Tx start turn the light on
@@ -473,9 +473,10 @@ char *convertSimuPath(const char *path)
 
 FRESULT f_stat (const TCHAR * name, FILINFO *)
 {
+  char *path = convertSimuPath(name);
   struct stat tmp;
-  // printf("f_stat(%s)\n", path); fflush(stdout);
-  return stat(convertSimuPath(name), &tmp) ? FR_INVALID_NAME : FR_OK;
+  TRACE("f_stat(%s)", path);
+  return stat(path, &tmp) ? FR_INVALID_NAME : FR_OK;
 }
 
 FRESULT f_mount (BYTE, FATFS*)
diff --git a/radio/src/targets/sky9x/diskio.cpp b/radio/src/targets/sky9x/diskio.cpp
index d7f60e900..8d9ff5cfc 100644
--- a/radio/src/targets/sky9x/diskio.cpp
+++ b/radio/src/targets/sky9x/diskio.cpp
@@ -1014,7 +1014,7 @@ void sdMountPoll()
 
     case SD_ST_DATA:
       if (!usbPlugged() && f_mount(0, &g_FATFS_Obj) == FR_OK) {
-        refreshSystemAudioFiles();
+        referenceSystemAudioFiles();
         Card_state = SD_ST_MOUNTED;
       }
       break;
@@ -1082,7 +1082,7 @@ void sdInit()
   Card_state = SD_ST_DATA;
 
   if (f_mount(0, &g_FATFS_Obj) == FR_OK) {
-    refreshSystemAudioFiles();
+    referenceSystemAudioFiles();
     Card_state = SD_ST_MOUNTED;
   }
 
diff --git a/radio/src/targets/taranis/diskio.cpp b/radio/src/targets/taranis/diskio.cpp
index b1d2dea7e..d9586804f 100644
--- a/radio/src/targets/taranis/diskio.cpp
+++ b/radio/src/targets/taranis/diskio.cpp
@@ -969,7 +969,7 @@ FIL g_telemetryFile = {0};
 void sdInit()
 {
   if (f_mount(0, &g_FATFS_Obj) == FR_OK) {
-    refreshSystemAudioFiles();
+    referenceSystemAudioFiles();
     
 #if defined(DEBUG)
     f_open(&g_telemetryFile, LOGS_PATH "/sport.log", FA_OPEN_ALWAYS | FA_WRITE);