// S_StartSound returns the channel index, or -1 if an error occurred
int S_StartSound (int entnum, int entchannel, sfx_t *sfx, vec3_t origin, float fvol, float attenuation);
int S_StartSound_StartPosition (int entnum, int entchannel, sfx_t *sfx, vec3_t origin, float fvol, float attenuation, float startposition);
-int S_StartSound_StartPosition_Flags (int entnum, int entchannel, sfx_t *sfx, vec3_t origin, float fvol, float attenuation, float startposition, int flags);
+int S_StartSound_StartPosition_Flags (int entnum, int entchannel, sfx_t *sfx, vec3_t origin, float fvol, float attenuation, float startposition, int flags, float fspeed);
qboolean S_LocalSound (const char *s);
void S_StaticSound (sfx_t *sfx, vec3_t origin, float fvol, float attenuation);
void S_StopChannel (unsigned int channel_ind, qboolean lockmutex, qboolean freesfx);
qboolean S_SetChannelFlag (unsigned int ch_ind, unsigned int flag, qboolean value);
void S_SetChannelVolume (unsigned int ch_ind, float fvol);
+void S_SetChannelSpeed (unsigned int ch_ind, float fspeed);
float S_GetChannelPosition (unsigned int ch_ind);
float S_GetEntChannelPosition(int entnum, int entchannel);