Convert sou to spx

What is the difference between .sou and .spx?

Description: The .sou file extension is associated with SBStudio II, a music composition and editing program. A .sou file represents a SBStudio II Sound File, which contains audio data used by the software. These files are typically used to store instrument sounds or sound effects that can be integrated into music tracks created within the SBStudio II environment. The format is designed specifically for use with the SBStudio II software, making it a specialized audio file type for music production within this specific program.; Audio file compressed using Speex compression and saved in the Ogg Vorbis container format; designed as an audio compression format specifically for speech; compresses voice at 2 to 44 kbps and supports 8 kHz, 16 kHz, and 32 kHz compression in the same bitstream.