diff --git a/include/functions.h b/include/functions.h
index d915a3e7d..23c537f0b 100644
--- a/include/functions.h
+++ b/include/functions.h
@@ -245,7 +245,7 @@ void osStopThread(OSThread* t);
 s32 osRecvMesg(OSMesgQueue* mq, OSMesg* msg, s32 flags);
 OSIntMask osSetIntMask(OSIntMask im);
 // OSIntMask osGetIntMask(void);
-// void osVoiceSetWord(void);
+s32 osVoiceSetWord(OSVoiceHandle* hd, u8* word);
 // void guScale(void);
 f32 __sinf(f32 __x);
 s16 sins(u16 x);
@@ -287,7 +287,7 @@ void osCreateThread(OSThread* t, OSId id, void* entry, void* arg, void* sp, OSPr
 s32 osContStartReadData(OSMesgQueue* mq);
 void osContGetReadData(OSContPad* data);
 void __osPackReadData(void);
-// void osVoiceGetReadData(void);
+s32 osVoiceGetReadData(OSVoiceHandle* hd, OSVoiceData* result);
 uintptr_t osVirtualToPhysical(void* vaddr);
 u32 __osGetSR(void);
 void __osSetSR(u32 value);
@@ -452,7 +452,7 @@ void viMgrMain(OSDevMgr* iParm1);
 __OSViContext* __osViGetCurrentContext(void);
 void osWritebackDCacheAll(void);
 OSThread* __osGetCurrFaultedThread(void);
-// void osVoiceMaskDictionary(void);
+s32 osVoiceMaskDictionary(OSVoiceHandle* hd, u8* maskPattern, s32 size);
 void guMtxF2L(float mf[4][4], Mtx* m);
 void osStartThread(OSThread* param_1);
 void osViSetYScale(f32 value);
@@ -465,7 +465,7 @@ double __ll_to_d(long long l);
 float __ll_to_f(long long l);
 double __ull_to_d(unsigned long long l);
 float __ull_to_f(unsigned long long l);
-// void osVoiceCheckWord(void);
+s32 osVoiceCheckWord(u8* word);
 s32 osVoiceControlGain(OSVoiceHandle* hd, s32 analog, s32 digital);
 s32 osVoiceStartReadData(OSVoiceHandle* hd);
 void* osViGetCurrentFramebuffer(void);
diff --git a/include/os.h b/include/os.h
index 47a419d6b..1a4712bff 100644
--- a/include/os.h
+++ b/include/os.h
@@ -122,6 +122,23 @@ typedef struct {
     /* 0xC */ u32* text_end;
 } OSProf; // size = 0x10
 
+#define VOICE_STATUS_READY 0 /* stop/end */
+#define VOICE_STATUS_START 1 /* Voice Undetected (no voice input) */
+#define VOICE_STATUS_CANCEL 3 /* Cancel (cancel extraneous noise) */
+#define VOICE_STATUS_BUSY 5 /* Detected/Detecting (voice being input, recognition processing under way) */
+#define VOICE_STATUS_END 7 /* End recognition processing (enable execution of Get Recognition Results command) */
+
+#define VOICE_WARN_TOO_SMALL 0x400 /* Voice level is too low (100 < Voice Level < 150) */
+#define VOICE_WARN_TOO_LARGE 0x800 /* Voice level is too high (Voice Level > 3500) */
+#define VOICE_WARN_NOT_FIT 0x4000 /* No words match recognition word (No. 1 Candidate Distance Value > 1600) */
+#define VOICE_WARN_TOO_NOISY 0x8000 /* Too much ambient noise (Relative Voice Level =< 400) */
+
+// #define CONT_ERR_NO_CONTROLLER
+// #define CONT_ERR_DEVICE
+// #define CONT_ERR_CONTRFAIL
+// #define CONT_ERR_VOICE_NO_RESPONSE
+// #define CONT_ERR_INVALID 
+
 typedef struct {
     /* 0x0 */ OSMesgQueue* mq;
     /* 0x4 */ s32 port; /* Controller port */
diff --git a/src/libultra/voice/voicecheckresult.c b/src/libultra/voice/voicecheckresult.c
index a20c88461..97af48094 100644
--- a/src/libultra/voice/voicecheckresult.c
+++ b/src/libultra/voice/voicecheckresult.c
@@ -1,21 +1,21 @@
 #include "global.h"
 
 s32 __osVoiceCheckResult(OSVoiceHandle* hd, u8* status) {
-    s32 phi_v1;
+    s32 errorCode;
     u8 sp20[2];
 
-    if (phi_v1 = __osVoiceGetStatus(hd->mq, hd->port, status), phi_v1 == 0) {
+    if (errorCode = __osVoiceGetStatus(hd->mq, hd->port, status), errorCode == 0) {
         if (*status & 1) {
-            phi_v1 = 0xF;
-        } else if (phi_v1 = __osVoiceContRead2(hd->mq, hd->port, 0, sp20), phi_v1 == 0) {
+            errorCode = 0xF;
+        } else if (errorCode = __osVoiceContRead2(hd->mq, hd->port, 0, sp20), errorCode == 0) {
             hd->status = sp20[0] & 7;
 
             if (sp20[0] & 0x40) {
-                phi_v1 = 0xF;
+                errorCode = 0xF;
             } else {
-                phi_v1 = sp20[1] << 8;
+                errorCode = sp20[1] << 8;
             }
         }
     }
-    return phi_v1;
+    return errorCode;
 }
diff --git a/src/libultra/voice/voicecleardictionary.c b/src/libultra/voice/voicecleardictionary.c
index 4de1eef59..92114809d 100644
--- a/src/libultra/voice/voicecleardictionary.c
+++ b/src/libultra/voice/voicecleardictionary.c
@@ -5,11 +5,11 @@ s32 osVoiceClearDictionary(OSVoiceHandle* hd, u8 words) {
     u8* registration_word;
     u8 status;
     s32 sp24;
-    s32 temp_v0;
+    s32 errorCode;
 
-    temp_v0 = __osVoiceGetStatus(hd->mq, hd->port, &status);
-    if (temp_v0 != 0) {
-        return temp_v0;
+    errorCode = __osVoiceGetStatus(hd->mq, hd->port, &status);
+    if (errorCode != 0) {
+        return errorCode;
     }
 
     registration_word = &sp24;
@@ -20,14 +20,15 @@ s32 osVoiceClearDictionary(OSVoiceHandle* hd, u8 words) {
     sp24 = 0x2000000;
     registration_word[2] = words;
 
-    temp_v0 = __osVoiceContWrite4(hd->mq, hd->port, 0, registration_word);
-    if (temp_v0 != 0) {
-        return temp_v0;
+    errorCode = __osVoiceContWrite4(hd->mq, hd->port, 0, registration_word);
+    if (errorCode != 0) {
+        return errorCode;
     }
 
-    temp_v0 = __osVoiceCheckResult(hd, &status);
-    if ((temp_v0 & 0xFF00) != 0) {
-        temp_v0 = 5;
+    errorCode = __osVoiceCheckResult(hd, &status);
+    if ((errorCode & 0xFF00) != 0) {
+        errorCode = 5;
     }
-    return temp_v0;
+
+    return errorCode;
 }
diff --git a/src/libultra/voice/voicecontrolgain.c b/src/libultra/voice/voicecontrolgain.c
index cfca63fbb..b0a66284a 100644
--- a/src/libultra/voice/voicecontrolgain.c
+++ b/src/libultra/voice/voicecontrolgain.c
@@ -4,7 +4,7 @@ extern u8 D_80098180[];
 
 // Adjusts the input gain of the Voice Recognition System
 s32 osVoiceControlGain(OSVoiceHandle* hd, s32 analog, s32 digital) {
-    s32 ret;
+    s32 errorCode;
     u8 phi_a2;
 
 
@@ -14,9 +14,9 @@ s32 osVoiceControlGain(OSVoiceHandle* hd, s32 analog, s32 digital) {
         phi_a2 = 0x98;
     }
 
-    ret = __osVoiceSetADConverter(hd->mq, hd->port, phi_a2, hd);
-    if (ret != 0) {
-        return ret;
+    errorCode = __osVoiceSetADConverter(hd->mq, hd->port, phi_a2, hd);
+    if (errorCode != 0) {
+        return errorCode;
     }
     
     if (!((digital < 8) && (digital >= 0))){
@@ -30,10 +30,10 @@ s32 osVoiceControlGain(OSVoiceHandle* hd, s32 analog, s32 digital) {
         return 5;
     }
 
-    ret = __osVoiceSetADConverter(hd->mq, hd->port, phi_a2, hd);
-    if (ret != 0) {
-        return ret;
+    errorCode = __osVoiceSetADConverter(hd->mq, hd->port, phi_a2, hd);
+    if (errorCode != 0) {
+        return errorCode;
     } 
 
-    return ret;
+    return errorCode;
 }
diff --git a/src/libultra/voice/voicestartreaddata.c b/src/libultra/voice/voicestartreaddata.c
index e0e696749..88c77dc2c 100644
--- a/src/libultra/voice/voicestartreaddata.c
+++ b/src/libultra/voice/voicestartreaddata.c
@@ -2,16 +2,16 @@
 
 // Start voice recognition by the Voice Recognition System
 s32 osVoiceStartReadData(OSVoiceHandle* hd) {
-    s32 ret;
-    u8 sp2B;
+    s32 errorCode;
+    u8 status;
     s32 sp24;
 
-    ret = __osVoiceGetStatus(hd->mq, hd->port, &sp2B);
-    if (ret != 0) {
-        return ret;
+    errorCode = __osVoiceGetStatus(hd->mq, hd->port, &status);
+    if (errorCode != 0) {
+        return errorCode;
     }
 
-    if ((sp2B & 2) != 0) {
+    if (status & 2) {
         return 0xF;
     }
 
@@ -20,17 +20,17 @@ s32 osVoiceStartReadData(OSVoiceHandle* hd) {
     }
 
     sp24 = 0x5000000;
-    ret = __osVoiceContWrite4(hd->mq, hd->port, 0, &sp24);
+    errorCode = __osVoiceContWrite4(hd->mq, hd->port, 0, &sp24);
 
-    if (ret == 0) {
-        ret = __osVoiceCheckResult(hd, &sp2B);
+    if (errorCode == 0) {
+        errorCode = __osVoiceCheckResult(hd, &status);
         
-        if ((ret & 0xFF00) != 0) {
-            ret = 5;
+        if (errorCode & 0xFF00) {
+            errorCode = 5;
         } else {
             hd->mode = 1;
         }
     }
 
-    return ret;
+    return errorCode;
 }