FLV is a Flash Video container used on popular hosting sites that stores audio, video and other data. It often uses h.264 or h.263 codecs for video storage and MP3 for audio. There are a lot of programs for both Windows and Mac operating systems that are able to open .flv files.

SPHERE (SPeech HEader Resources) is a file format defined by NIST (National Institute of Standards and Technology) and is used with speech audio. SoX can read these files when they contain μ-law and PCM data. It will ignore any header information that says the data is compressed using shorten compression and will treat the data as either μ-law or PCM. This will allow SoX and the command line shorten program to be run together using pipes to encompasses the data and then pass the result to SoX for processing.