one of the most common audio formats. The format was developed by Microsoft (in collaboration with IBM) and usually stores uncompressed audio data with pulse-code modulation, but it can be used to store sound processed with other audio codecs.
An SPX file is a Speex audio file saved within an Ogg Vorbis container. Speex is an open source patent-free audio format designed for speech compression. It supports variable bitrate (VBR) encoding and several features not found in other audio codecs. Some examples include embedded encoding, intensity stereo encoding, and voice activity detection.