slower step sound when moving slow

Change-Id: I49e263e5e7bdc0ed24c69e97f21828e73fab1c14
bullet explosion

Change-Id: Iec7e31fe060ae379b3384aa8932f8e333828d14f
tank explosion sounds

Change-Id: Ic94d3955e6140e497028a4d433b1e89551f2474b