Speex (.spx)

Speex is an audio format designed specifically for speech recording. Speex courses have the following Audio Dialog Box:

Speex

.wav File Specifications

Note: The Speex Browse buttons are labeled 8bit and 16bit. This refers to the output bit depth, not the input .wav file bit depth.

To convert to 8bit .spx audio file format, the .wav file must be 16bit 8kHz mono PCM.
To convert to 16bit .spx audio file format, the .wav file must be 16bit 16kHz mono PCM.