diff --git a/include/struct_decls/struct_02003D54_decl.h b/include/struct_decls/struct_02003D54_decl.h
deleted file mode 100644
index 3b816c697b..0000000000
--- a/include/struct_decls/struct_02003D54_decl.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#ifndef POKEPLATINUM_STRUCT_02003D54_DECL_H
-#define POKEPLATINUM_STRUCT_02003D54_DECL_H
-
-typedef struct UnkStruct_02003D54_t UnkStruct_02003D54;
-
-#endif // POKEPLATINUM_STRUCT_02003D54_DECL_H
diff --git a/include/unk_02003B60.h b/include/unk_02003B60.h
index 2ab464dea9..802265f159 100644
--- a/include/unk_02003B60.h
+++ b/include/unk_02003B60.h
@@ -3,15 +3,61 @@
 
 #include <nnsys.h>
 
-#include "struct_decls/struct_02003D54_decl.h"
 #include "struct_defs/chatot_cry.h"
-
 #include "game_options.h"
 
+typedef struct SoundSystem {
+    NNSSndArc unk_00;
+    NNSSndHeapHandle unk_F8;
+    u8 unk_FC[769024];
+    NNSSndHandle unk_BBCFC[9];
+    NNSSndWaveOutHandle unk_BBD20[2];
+    const NNSSndArcBankInfo *unk_BBD28;
+    u8 unk_BBD2C[4096] ATTRIBUTE_ALIGN(32);
+    UnkStruct_020052C8 unk_BCD2C;
+    u16 unk_BCD48;
+    u8 unk_BCD4A;
+    u8 unk_BCD4B;
+    int unk_BCD4C;
+    int unk_BCD50;
+    int unk_BCD54;
+    u16 unk_BCD58;
+    u16 unk_BCD5A;
+    u8 unk_BCD5C;
+    u8 unk_BCD5D;
+    u16 unk_BCD5E;
+    u8 unk_BCD60;
+    u8 unk_BCD61;
+    u8 unk_BCD62;
+    u8 unk_BCD63;
+    u8 unk_BCD64;
+    u8 unk_BCD65;
+    u8 unk_BCD66;
+    u8 unk_BCD67;
+    int unk_BCD68[7];
+    u8 unk_BCD84;
+    u8 unk_BCD85;
+    u16 unk_BCD86;
+    const SNDWaveData *unk_BCD88;
+    void *unk_BCD8C;
+    int unk_BCD90;
+    SysTask *unk_BCD94;
+    ChatotCry *unk_BCD98;
+    ChatotCry *unk_BCD9C[4];
+    int unk_BCDAC[2];
+    int unk_BCDB4[2];
+    int unk_BCDBC[2];
+    int unk_BCDC4[2];
+    u16 unk_BCDCC[2];
+    u8 unk_BCDD0[2];
+    u8 unk_BCDD2;
+    u8 unk_BCDD3;
+} SoundSystem;
+
 void sub_02003B60(ChatotCry *param0, Options *param1);
 void UpdateSound(void);
 void sub_02003D0C(int param0);
-UnkStruct_02003D54 *sub_02003D54(void);
+SoundSystem *sub_02003D54(void);
 void *sub_02003D5C(int param0);
 int sub_02004014(int *param0);
 void sub_0200403C(int param0);
diff --git a/src/unk_02003B60.c b/src/unk_02003B60.c
index 4f1b8dd053..b737dd78e1 100644
--- a/src/unk_02003B60.c
+++ b/src/unk_02003B60.c
@@ -3,7 +3,6 @@
 #include <nitro.h>
 #include <string.h>
 
-#include "struct_decls/struct_02003D54_decl.h"
 #include "struct_defs/chatot_cry.h"
 #include "struct_defs/struct_020052C8.h"
 
@@ -13,69 +12,23 @@
 #include "unk_02005474.h"
 #include "unk_02006224.h"
 
-struct UnkStruct_02003D54_t {
-    NNSSndArc unk_00;
-    NNSSndHeapHandle unk_F8;
-    u8 unk_FC[769024];
-    NNSSndHandle unk_BBCFC[9];
-    NNSSndWaveOutHandle unk_BBD20[2];
-    const NNSSndArcBankInfo *unk_BBD28;
-    u8 unk_BBD2C[4096] ATTRIBUTE_ALIGN(32);
-    UnkStruct_020052C8 unk_BCD2C;
-    u16 unk_BCD48;
-    u8 unk_BCD4A;
-    u8 unk_BCD4B;
-    int unk_BCD4C;
-    int unk_BCD50;
-    int unk_BCD54;
-    u16 unk_BCD58;
-    u16 unk_BCD5A;
-    u8 unk_BCD5C;
-    u8 unk_BCD5D;
-    u16 unk_BCD5E;
-    u8 unk_BCD60;
-    u8 unk_BCD61;
-    u8 unk_BCD62;
-    u8 unk_BCD63;
-    u8 unk_BCD64;
-    u8 unk_BCD65;
-    u8 unk_BCD66;
-    u8 unk_BCD67;
-    int unk_BCD68[7];
-    u8 unk_BCD84;
-    u8 unk_BCD85;
-    u16 unk_BCD86;
-    const SNDWaveData *unk_BCD88;
-    void *unk_BCD8C;
-    int unk_BCD90;
-    SysTask *unk_BCD94;
-    ChatotCry *unk_BCD98;
-    ChatotCry *unk_BCD9C[4];
-    int unk_BCDAC[2];
-    int unk_BCDB4[2];
-    int unk_BCDBC[2];
-    int unk_BCDC4[2];
-    u16 unk_BCDCC[2];
-    u8 unk_BCDD0[2];
-    u8 unk_BCDD2;
-    u8 unk_BCDD3;
-};
 
-static void sub_0200413C(UnkStruct_02003D54 *param0);
-static void sub_02004160(UnkStruct_02003D54 *param0);
-static void sub_0200417C(UnkStruct_02003D54 *param0);
+
+static void sub_0200413C(SoundSystem *param0);
+static void sub_02004160(SoundSystem *param0);
+static void sub_0200417C(SoundSystem *param0);
 static void sub_020041A0(void);
 static BOOL sub_02003D28(void);
 static void sub_02003C64(void);
 static void sub_020041B4(void);
 
-static UnkStruct_02003D54 Unk_02101DF8;
+static SoundSystem sSoundSystem;
 static int Unk_02101DF0;
 static NNSSndCaptureOutputEffectType Unk_02101DF4;
 
 void sub_02003B60(ChatotCry *param0, Options *param1)
 {
-    UnkStruct_02003D54 *v0 = sub_02003D54();
+    SoundSystem *v0 = sub_02003D54();
 
     NNS_SndInit();
 
@@ -100,7 +53,7 @@ void sub_02003B60(ChatotCry *param0, Options *param1)
 
 void UpdateSound(void)
 {
-    UnkStruct_02003D54 *v1 = sub_02003D54();
+    SoundSystem *v1 = sub_02003D54();
 
     if (sub_02003D28() == 0) {
         if (v1->unk_BCD4C > 0) {
@@ -129,7 +82,7 @@ void UpdateSound(void)
 static void sub_02003C64(void)
 {
     int v0;
-    UnkStruct_02003D54 *v1 = sub_02003D54();
+    SoundSystem *v1 = sub_02003D54();
 
     switch (Unk_02101DF0) {
     case 0:
@@ -173,7 +126,7 @@ static void sub_02003C64(void)
 
 void sub_02003D0C(int param0)
 {
-    UnkStruct_02003D54 *v0 = sub_02003D54();
+    SoundSystem *v0 = sub_02003D54();
 
     v0->unk_BCD48 = 0;
     Unk_02101DF0 = param0;
@@ -183,7 +136,7 @@ void sub_02003D0C(int param0)
 
 static BOOL sub_02003D28(void)
 {
-    UnkStruct_02003D54 *v0 = sub_02003D54();
+    SoundSystem *v0 = sub_02003D54();
 
     if (sub_02004B04(2) != 0) {
         return 1;
@@ -196,14 +149,14 @@ static BOOL sub_02003D28(void)
     return 0;
 }
 
-UnkStruct_02003D54 *sub_02003D54()
+SoundSystem *sub_02003D54()
 {
-    return (UnkStruct_02003D54 *)&Unk_02101DF8;
+    return &sSoundSystem;
 }
 
 void *sub_02003D5C(int param0)
 {
-    UnkStruct_02003D54 *v0 = sub_02003D54();
+    SoundSystem *v0 = sub_02003D54();
 
     switch (param0) {
     case 5:
@@ -325,7 +278,7 @@ void *sub_02003D5C(int param0)
 int sub_02004014(int *param0)
 {
     int v0;
-    UnkStruct_02003D54 *v1 = sub_02003D54();
+    SoundSystem *v1 = sub_02003D54();
 
     v0 = NNS_SndHeapSaveState(v1->unk_F8);
 
@@ -342,7 +295,7 @@ int sub_02004014(int *param0)
 
 void sub_0200403C(int param0)
 {
-    UnkStruct_02003D54 *v0 = sub_02003D54();
+    SoundSystem *v0 = sub_02003D54();
 
     NNS_SndHeapLoadState(v0->unk_F8, param0);
     return;
@@ -351,7 +304,7 @@ void sub_0200403C(int param0)
 BOOL sub_02004050(u16 param0)
 {
     int v0;
-    UnkStruct_02003D54 *v1 = sub_02003D54();
+    SoundSystem *v1 = sub_02003D54();
 
     v0 = NNS_SndArcLoadGroup(param0, v1->unk_F8);
     return v0;
@@ -360,7 +313,7 @@ BOOL sub_02004050(u16 param0)
 BOOL sub_02004068(u16 param0)
 {
     int v0;
-    UnkStruct_02003D54 *v1 = sub_02003D54();
+    SoundSystem *v1 = sub_02003D54();
 
     v0 = NNS_SndArcLoadSeq(param0, v1->unk_F8);
     return v0;
@@ -369,7 +322,7 @@ BOOL sub_02004068(u16 param0)
 BOOL sub_02004080(u16 param0, u32 param1)
 {
     int v0;
-    UnkStruct_02003D54 *v1 = sub_02003D54();
+    SoundSystem *v1 = sub_02003D54();
 
     v0 = NNS_SndArcLoadSeqEx(param0, param1, v1->unk_F8);
     return v0;
@@ -378,7 +331,7 @@ BOOL sub_02004080(u16 param0, u32 param1)
 BOOL sub_0200409C(u16 param0)
 {
     int v0;
-    UnkStruct_02003D54 *v1 = sub_02003D54();
+    SoundSystem *v1 = sub_02003D54();
 
     v0 = NNS_SndArcLoadWaveArc(param0, v1->unk_F8);
     return v0;
@@ -387,7 +340,7 @@ BOOL sub_0200409C(u16 param0)
 BOOL sub_020040B4(u16 param0)
 {
     int v0;
-    UnkStruct_02003D54 *v1 = sub_02003D54();
+    SoundSystem *v1 = sub_02003D54();
 
     v0 = NNS_SndArcLoadBank(param0, v1->unk_F8);
     return v0;
@@ -395,7 +348,7 @@ BOOL sub_020040B4(u16 param0)
 
 NNSSndHandle *sub_020040CC(int param0)
 {
-    UnkStruct_02003D54 *v0 = sub_02003D54();
+    SoundSystem *v0 = sub_02003D54();
 
     if (param0 >= 9) {
         GF_ASSERT(FALSE);
@@ -443,11 +396,11 @@ int sub_020040F0(int param0)
     return v0;
 }
 
-static void sub_0200413C(UnkStruct_02003D54 *param0)
+static void sub_0200413C(SoundSystem *param0)
 {
     int v0;
 
-    memset(param0, 0, sizeof(UnkStruct_02003D54));
+    memset(param0, 0, sizeof(SoundSystem));
 
     for (v0 = 0; v0 < 7; v0++) {
         param0->unk_BCD68[v0] = (v0 + 1);
@@ -456,7 +409,7 @@ static void sub_0200413C(UnkStruct_02003D54 *param0)
     return;
 }
 
-static void sub_02004160(UnkStruct_02003D54 *param0)
+static void sub_02004160(SoundSystem *param0)
 {
     int v0;
 
@@ -467,7 +420,7 @@ static void sub_02004160(UnkStruct_02003D54 *param0)
     return;
 }
 
-static void sub_0200417C(UnkStruct_02003D54 *param0)
+static void sub_0200417C(SoundSystem *param0)
 {
     int v0;
 
diff --git a/src/unk_020041CC.c b/src/unk_020041CC.c
index d5789be673..b9eba55ca0 100644
--- a/src/unk_020041CC.c
+++ b/src/unk_020041CC.c
@@ -3,7 +3,6 @@
 #include <nitro.h>
 #include <string.h>
 
-#include "struct_decls/struct_02003D54_decl.h"
 #include "struct_defs/struct_02004CB4.h"
 #include "struct_defs/struct_020052C8.h"
 
@@ -585,7 +584,7 @@ static void sub_02004930(u8 param0, u16 param1, int param2)
 void sub_02004950(u16 param0)
 {
     int v0;
-    UnkStruct_02003D54 *v1 = sub_02003D54();
+    SoundSystem *v1 = sub_02003D54();
 
     sub_0200540C();
 
@@ -602,7 +601,7 @@ void sub_02004964(void)
 int sub_02004974(int param0)
 {
     int *v0;
-    UnkStruct_02003D54 *v1 = sub_02003D54();
+    SoundSystem *v1 = sub_02003D54();
 
     if (param0 >= 7) {
         GF_ASSERT(FALSE);
@@ -811,7 +810,7 @@ MICResult sub_02004B5C(MICAutoParam *param0)
 MICResult sub_02004B64(void)
 {
     MICResult v0;
-    UnkStruct_02003D54 *v1 = sub_02003D54();
+    SoundSystem *v1 = sub_02003D54();
 
     v0 = MIC_StopAutoSampling();
 
@@ -837,7 +836,7 @@ MICResult sub_02004B70(MICSamplingType param0, void *param1, MICCallback param2,
 
 NNSSndWaveOutHandle *sub_02004B78(u32 param0)
 {
-    UnkStruct_02003D54 *v0 = sub_02003D54();
+    SoundSystem *v0 = sub_02003D54();
     u8 *v1 = sub_02003D5C(16);
     u8 *v2 = sub_02003D5C(17);
 
@@ -865,7 +864,7 @@ BOOL sub_02004BCC(u32 param0)
     u8 *v0;
     u8 *v1;
     NNSSndWaveOutHandle *v2;
-    UnkStruct_02003D54 *v3 = sub_02003D54();
+    SoundSystem *v3 = sub_02003D54();
 
     v0 = sub_02003D5C(16);
     v1 = sub_02003D5C(17);
@@ -908,7 +907,7 @@ BOOL sub_02004BCC(u32 param0)
 void sub_02004C4C(u32 param0)
 {
     NNSSndWaveOutHandle *v0;
-    UnkStruct_02003D54 *v1 = sub_02003D54();
+    SoundSystem *v1 = sub_02003D54();
     u8 *v2 = sub_02003D5C(16);
     u8 *v3 = sub_02003D5C(17);
 
@@ -997,7 +996,7 @@ BOOL sub_02004D78(u16 param0, int param1, int param2, u32 param3, int heapID)
     const NNSSndArcWaveArcInfo *v1;
     u32 v2;
     int v3, v4;
-    UnkStruct_02003D54 *v5 = sub_02003D54();
+    SoundSystem *v5 = sub_02003D54();
     void **v6 = sub_02003D5C(34);
 
     if ((param3 != 14) && (param3 != 15)) {
@@ -1079,7 +1078,7 @@ static void sub_02004E64(u8 *param0, u32 param1)
 
 void sub_02004E84(u32 param0)
 {
-    UnkStruct_02003D54 *v0 = sub_02003D54();
+    SoundSystem *v0 = sub_02003D54();
     u8 *v1 = sub_02003D5C(15);
     void **v2 = sub_02003D5C(34);
 
@@ -1108,7 +1107,7 @@ BOOL sub_02004EC0(void)
 
 BOOL sub_02004EC8(int param0)
 {
-    UnkStruct_02003D54 *v0 = sub_02003D54();
+    SoundSystem *v0 = sub_02003D54();
     s8 *v1 = sub_02003D5C(3);
 
     return NNS_SndCaptureStartReverb(v1, 0x1000, (NNS_SND_CAPTURE_FORMAT_PCM16), 16000, param0);
@@ -1128,7 +1127,7 @@ void sub_02004EF4(int param0, int param1)
 
 BOOL sub_02004EFC(void)
 {
-    UnkStruct_02003D54 *v1 = sub_02003D54();
+    SoundSystem *v1 = sub_02003D54();
 
     MI_CpuClear8(sub_02003D5C(4), sizeof(UnkStruct_020052C8));
     return NNS_SndCaptureStartEffect(sub_02003D5C(3), 0x1000, NNS_SND_CAPTURE_FORMAT_PCM16, 22000, 2, sub_020052C8, sub_02003D5C(4));