Speex is an application designed for users who need to work with audio files that contain speech and want to shrink them. Live recordings are usually the ones that are targeted by such a tool and users have the option to convert these in a matter of seconds in order to drastically reduce them in size. There are multiple band options, starting from the narrow 8kHz one and going up to the ultra-band, at 32kHz.
The utility can also clean an audio file that contains speech in order to make voices clear. A noise suppression tool is able to block unwanted noises from different sources, while the echo canceler feature is able to remove any echo effect that might appear at multiple points throughout the recording. In the end, the resulting sound file is shrunk a lot in comparison to the original one that might have been encoded at well beyond 48kHz.