diff --git a/src/audio.c b/src/audio.c
index 678938e21c..0b89bc68d3 100644
--- a/src/audio.c
+++ b/src/audio.c
@@ -187,6 +187,18 @@ int sound_load3dparameters()
 	return 0;
 }
 
+/**
+*
+*  rct2: 0x00404F3F
+*/
+int sound_load3dposition()
+{
+	/*if (SUCCEEDED(RCT2_GLOBAL(0x009E2BA4, LPDIRECTSOUND3DBUFFER)->lpVtbl->GetPosition(RCT2_GLOBAL(0x009E2BA4, LPDIRECTSOUND3DBUFFER), &RCT2_GLOBAL(0x009A6084, DS3DBUFFER), 1))) {
+		return 1;
+	}*/
+	return 0;
+}
+
 /**
 *
 *  rct2: 0x00404932
@@ -240,7 +252,7 @@ int dsound_create_primary_buffer(int a, int device, int channels, int samples, i
 			RCT2_GLOBAL(0x009A6084, DS3DBUFFER).vPosition.x = -1.0f;
 			RCT2_GLOBAL(0x009A6084, DS3DBUFFER).flMaxDistance = 9.8999996f;
 			RCT2_GLOBAL(0x009A6084, DS3DBUFFER).flMinDistance = 0.25f;
-			if (RCT2_CALLFUNC(0x00404F3F, int)) {
+			if (sound_load3dposition()) {
 				if (SUCCEEDED(RCT2_GLOBAL(0x009E2BA4, LPDIRECTSOUND3DBUFFER)->lpVtbl->SetMinDistance(RCT2_GLOBAL(0x009E2BA4, LPDIRECTSOUND3DBUFFER), RCT2_GLOBAL(0x009A6084, DS3DBUFFER).flMinDistance, 1))) {
 					if (sound_load3dparameters()) {
 						return 1;
@@ -338,13 +350,305 @@ int map_sound_info(const char* filename)
 	}
 }
 
+/**
+*
+*  rct2: 0x00405383
+*/
+MMRESULT sub_405383(HMMIO hmmio, uint32 size, char* buffer, LPMMCKINFO a4, int* read)
+{
+	MMIOINFO mmioinfo;
+	MMRESULT result;
+	result = mmioGetInfo(hmmio, &mmioinfo, 0);
+	if (result != 0) {
+		*read = 0;
+		return 1;
+	}
+	int size2 = size;
+	if (size > a4->cksize) {
+		size2 = a4->cksize;
+	}
+	int v8 = 0;
+	a4->cksize -= size2;
+	if (size2) {
+		while (1) {
+			HPSTR p = mmioinfo.pchEndRead;
+			if (mmioinfo.pchNext == mmioinfo.pchEndRead) {
+				result = mmioAdvance(hmmio, &mmioinfo, 0);
+				if (result != 0) {
+					*read = 0;
+					return result;
+				}
+				p = mmioinfo.pchEndRead;
+				if (mmioinfo.pchNext == mmioinfo.pchEndRead) {
+					break;
+				}
+			}
+			int q = p - mmioinfo.pchNext;
+			if (size2 - v8 < p - mmioinfo.pchNext) {
+				q = size2 - v8;
+			}
+			memcpy(&buffer[v8], mmioinfo.pchNext, q);
+			mmioinfo.pchNext += q;
+			v8 += q;
+			if (v8 >= size2) {
+				result = mmioSetInfo(hmmio, &mmioinfo, 0);
+				if (result != 0) {
+					*read = 0;
+					return result;
+				} else {
+					*read = size2;
+					return result;
+				}
+			}
+		}
+		*read = 0;
+		return 57603;
+	}
+	result = mmioSetInfo(hmmio, &mmioinfo, 0);
+	if (result != 0) {
+		*read = 0;
+		return result;
+	} else {
+		*read = size2;
+		return result;
+	}
+}
+
+/**
+*
+*  rct2: 0x00401822
+*/
+int sub_401822(int channel, HMMIO* hmmio, LONG offset)
+{
+	rct_sound_channel* sound_channel = &RCT2_ADDRESS(0x014262E0, rct_sound_channel)[channel];
+	LPMMCKINFO v4 = &sound_channel->mmckinfo2;
+	HMMIO* v5 = &sound_channel->hmmio;
+	if (RCT2_CALLFUNC_4(0x00405222, int, HMMIO*, HMMIO*, HGLOBAL*, LPMMCKINFO, hmmio, &sound_channel->hmmio, &sound_channel->hmem, &sound_channel->mmckinfo2)) {
+		return -100;
+	}
+	if (*(uint16*)sound_channel->hmem != 1) {
+		sound_channel_free(&sound_channel->hmmio, &sound_channel->hmem);
+		return -101;
+	}
+	if (RCT2_CALLFUNC_4(0x00405465, int, HMMIO*, LPMMCKINFO, LPMMCKINFO, int, &sound_channel->hmmio, &sound_channel->mmckinfo1, &sound_channel->mmckinfo2, offset)) {
+		sound_channel_free(&sound_channel->hmmio, &sound_channel->hmem);
+		return -103;
+	}
+	sound_channel->var_158 = offset;
+	return 0;
+}
+
+/**
+*
+*  rct2: 0x0040153B
+*/
+int sub_40153B(int channel)
+{
+	rct_sound_channel* sound_channel = &RCT2_ADDRESS(0x014262E0, rct_sound_channel)[channel];
+	if (sound_channel->var_4) {
+		if (sound_channel->hmmio) {
+			sound_channel_free(&sound_channel->hmmio, &sound_channel->hmem);
+		}
+		if (sub_401822(channel, (HMMIO*)&sound_channel->var_8, sound_channel->var_110)) {
+			return 0;
+		}
+		sound_channel->var_164 = sound_channel->var_114;
+		sound_channel->var_118 = sound_channel->var_110;
+		sound_channel->var_4 = 0;
+	} else {
+		int result = RCT2_CALLFUNC_4(0x00405465, int, HMMIO*, LPMMCKINFO, LPMMCKINFO, int, &sound_channel->hmmio, &sound_channel->mmckinfo1, &sound_channel->mmckinfo2, sound_channel->var_118);
+		sound_channel->var_158 = sound_channel->var_118;
+		if (result) {
+			return 0;
+		}
+	}
+	return 1;
+}
+
 /**
 *
 *  rct2: 0x00401000
 */
 void sub_401000(UINT uTimerID, UINT uMsg, DWORD_PTR dwUser, DWORD_PTR dw1, DWORD_PTR dw2, int channel)
 {
-	RCT2_CALLFUNC_6(0x00401000, void, UINT, UINT, DWORD_PTR, DWORD_PTR, DWORD_PTR, int, uTimerID, uMsg, dwUser, dw1, dw2, channel);
+	rct_sound_channel* sound_channel = &RCT2_ADDRESS(0x014262E0, rct_sound_channel)[channel];
+	DWORD status;
+	DWORD dwCurrentPlayCursor;
+	DWORD dwCurrentWriteCursor;
+	uint32 var1;
+	int var2;
+	int bufferlost = 0;
+	char* buf1;
+	int buf1size;
+	char* buf2;
+	int buf2size;
+	sound_channel->dsbuffer->lpVtbl->GetStatus(sound_channel->dsbuffer, &status);
+	if (status & DSBSTATUS_BUFFERLOST) {
+		if (FAILED(sound_channel->dsbuffer->lpVtbl->Restore(sound_channel->dsbuffer))) {
+			return;
+		}
+		sound_channel->playpos = 0;
+		bufferlost = 1;
+	}
+	sound_channel->dsbuffer->lpVtbl->GetCurrentPosition(sound_channel->dsbuffer, &dwCurrentPlayCursor, &dwCurrentWriteCursor);
+	if (dwCurrentPlayCursor != sound_channel->playpos || bufferlost) {
+		if (sound_channel->var_168 && !sound_channel->var_15C) {
+			if (!sound_channel->var_160) {
+				sound_channel->var_160 = 1;
+				if (!sound_channel->var_4) {
+					LPDIRECTSOUNDBUFFER dsbuffer = RCT2_ADDRESS(RCT2_ADDRESS_DSOUND_BUFFERS, LPDIRECTSOUNDBUFFER)[channel];
+					sound_channel->var_0 = 0;
+					if (dsbuffer) {
+						dsbuffer->lpVtbl->Stop(dsbuffer);
+						dsbuffer->lpVtbl->Release(dsbuffer);
+						RCT2_ADDRESS(RCT2_ADDRESS_DSOUND_BUFFERS, LPDIRECTSOUNDBUFFER)[channel] = 0;
+					}
+					if (sound_channel->hmmio) {
+						sound_channel_free(&sound_channel->hmmio, &sound_channel->hmem);
+					}
+				}
+			}
+			return;
+		}
+		if (dwCurrentPlayCursor >= sound_channel->playpos) {
+			var1 = dwCurrentPlayCursor - sound_channel->playpos;
+		} else {
+			var1 = dwCurrentPlayCursor + sound_channel->var_150 - sound_channel->playpos;
+		}
+		if (bufferlost) {
+			var2 = 2 * sound_channel->var_150 / 6;
+		} else {
+			var2 = var1;
+		}
+		sound_channel->var_158 += var1;
+		if (sound_channel->var_168) {
+			uint32 var3 = sound_channel->var_15C;
+			uint32* var4 = &sound_channel->var_15C;
+			if (var3) {
+				if (var1 <= var3) {
+					*var4 = var3 - var1;
+				} else {
+					*var4 = 0;
+				}
+				if (SUCCEEDED(sound_channel->dsbuffer->lpVtbl->Lock(sound_channel->dsbuffer, sound_channel->playpos, var2, (LPVOID*)&buf1, (LPDWORD)&buf1size, (LPVOID*)&buf2, (LPDWORD)&buf2size, 0))) {
+					uint16 var5 = -(sound_channel->mmckinfo1.cksize != 8);
+					var5 &= 0x80;
+					memset(buf1, var5 + 128, buf1size);
+					if (buf2 && buf2size) {
+						uint16 var5 = -(sound_channel->mmckinfo1.cksize != 8);
+						var5 &= 0x80;
+						memset(buf2, var5 + 128, buf2size);
+					}
+					sound_channel->dsbuffer->lpVtbl->Unlock(sound_channel->dsbuffer, buf1, buf1size, buf2, buf2size);
+					sound_channel->playpos += var2;
+					if (sound_channel->playpos >= sound_channel->var_150) {
+						sound_channel->playpos = sound_channel->playpos - sound_channel->var_150;
+					}
+					return;
+				}
+				// TimeFunc() could not lock DirectSoundBuffer
+				return;
+			}
+		}
+		if (FAILED(sound_channel->dsbuffer->lpVtbl->Lock(sound_channel->dsbuffer, sound_channel->playpos, var2, (LPVOID*)&buf1, (LPDWORD)&buf1size, (LPVOID*)&buf2, &buf2size, 0))) {
+			// TimeFunc() could not lock DirectSoundBuffer
+			return;
+		}
+		if (buf1size) {
+			if (sound_channel->var_160) {
+				uint16 var5 = -(sound_channel->mmckinfo1.cksize != 8);
+				var5 &= 0x80;
+				memset(buf1, var5 + 128, buf1size);
+				goto label49;
+			}
+		}
+		int var7;
+		sub_405383(sound_channel->hmmio, buf1size, buf1, &sound_channel->mmckinfo1, &var7);
+		if (var7 < buf1size) {
+			if (!sound_channel->var_164) {
+				int s = sound_channel->mmckinfo1.cksize;
+				int t = buf1size - var7;
+				int v;
+				if (s == 8) {
+					v = 128;
+				} else {
+					if (s != 16) {
+						goto label42;
+					}
+					v = 0;
+				}
+				memset(&buf1[var7], v, t);
+			label42:
+				sound_channel->var_168 = 1;
+				if (dwCurrentPlayCursor <= sound_channel->playpos) {
+					sound_channel->var_15C = sound_channel->playpos - dwCurrentPlayCursor;
+				} else {
+					sound_channel->var_15C = sound_channel->playpos + sound_channel->var_150 - dwCurrentPlayCursor;
+				}
+				goto label49;
+			}
+			char* v21 = buf1;
+			int v38 = buf1size;
+			do {
+				v38 -= var7;
+				v21 += var7;
+				sub_40153B(channel);//RCT2_CALLFUNC_1(0x0040153B, int, int, channel);
+				sub_405383(sound_channel->hmmio, v38, v21, &sound_channel->mmckinfo1, &var7);
+			} while(var7 < v38);
+		}
+	label49:
+		if (buf2size == 0 || sound_channel->var_160 != 0) {
+			if(buf2 != 0 && buf2size != 0 && sound_channel->var_160 != 0) {
+				int var5 = -(sound_channel->mmckinfo1.cksize != 8);
+				var5 &= 0x80;
+				memset(buf2, var5 + 128, buf2size);
+			}
+			goto label68;
+		}
+		sub_405383(sound_channel->hmmio, buf2size, buf2, &sound_channel->mmckinfo1, &var7);
+		if (var7 >= buf2size) {
+		label68:
+			sound_channel->dsbuffer->lpVtbl->Unlock(sound_channel->dsbuffer, buf1, buf1size, buf2, buf2size);
+			sound_channel->playpos += var2;
+			if (sound_channel->playpos >= sound_channel->var_150) {
+				sound_channel->playpos -= sound_channel->var_150;
+			}
+			if (bufferlost != 0) {
+				sound_channel->dsbuffer->lpVtbl->Play(sound_channel->dsbuffer, 0, 0, DSBPLAY_LOOPING);
+			}
+			return;
+		}
+		if (sound_channel->var_164 != 0) {
+			char* v26 = buf2;
+			int v27 = buf2size;
+			do {
+				v26 += var7;
+				v27 -= var7;
+				sub_40153B(channel);//RCT2_CALLFUNC_1(0x0040153B, int, int, channel);
+				sub_405383(sound_channel->hmmio, v27, v26, &sound_channel->mmckinfo1, &var7);
+			} while(var7 < v27);
+			goto label68;
+		}
+		int s = buf2size - var7;
+		int v;
+		if (sound_channel->hmem == (HGLOBAL)8) {
+			v = 128;
+		} else {
+			if (sound_channel->hmem != (HGLOBAL)16) {
+				goto label58;
+			}
+			v = 0;
+		}
+		memset(&buf2[var7], v, s);
+	label58:
+		sound_channel->var_168 = 1;
+		if (dwCurrentPlayCursor <= sound_channel->playpos) {
+			sound_channel->var_15C = sound_channel->playpos - dwCurrentPlayCursor;
+		} else {
+			sound_channel->var_15C = sound_channel->playpos + sound_channel->var_150 - dwCurrentPlayCursor;
+		}
+		goto label68;
+	}
 }
 
 /**
@@ -1047,7 +1351,7 @@ int sound_channel_stop(int channel)
 	while (_InterlockedExchange(&RCT2_GLOBAL(0x009E1AAC, LONG), 1) != 1) {
 		Sleep(10);
 	}
-	if (sound_channel->hmem) {
+	if (sound_channel->hmmio) {
 		sound_channel_free(&sound_channel->hmmio, &sound_channel->hmem);
 	}
 
diff --git a/src/audio.h b/src/audio.h
index 85aba58db8..2848af7840 100644
--- a/src/audio.h
+++ b/src/audio.h
@@ -69,10 +69,21 @@ typedef struct {
 
 typedef struct {
 	uint32 var_0;
-	uint8 pad_4[0x118];
-	HMMIO hmmio;
-	HGLOBAL hmem;
-	uint8 pad_124[0x3C];
+	uint32 var_4;
+	uint32 var_8;
+	uint8 pad_C[0x104];
+	uint32 var_110;
+	uint32 var_114;
+	uint32 var_118;
+	HGLOBAL hmem;					// 0x11C
+	HMMIO hmmio;					// 0x120
+	MMCKINFO mmckinfo1;				// 0x124
+	MMCKINFO mmckinfo2;				// 0x138
+	LPDIRECTSOUNDBUFFER dsbuffer;	// 0x14C
+	uint32 var_150;
+	uint32 playpos;					// 0x154
+	uint32 var_158;
+	uint32 var_15C;
 	uint32 var_160;
 	uint32 var_164;
 	uint32 var_168;
@@ -112,6 +123,7 @@ int sound_channel_play(int channel, int a2, int volume, int pan, int frequency);
 int sound_channel_set_frequency(int channel, int frequency);
 int sound_channel_set_pan(int channel, int pan);
 int sound_channel_set_volume(int channel, int volume);
+void sound_channel_free(HMMIO* hmmio, HGLOBAL* hmem);
 int sound_stop(rct_sound *sound);
 int sound_stop_all();
 int unmap_file(LPCVOID base);