The aim of its developers was offering a convenient and patent-free alternative to costly proprietary speech codecs.
Speex is mostly used in Internet applications and you need special software in order to handle it.
The Winamp Speex decoder makes it possible for you to play SPX files in Winamp. The last version of the decoder also allows you to play streams, aside from local files.
In order to install the Winamp Speex decoder, you need to copy the in_speex.dll file to the Plugins subdirectory of Winamp.
The most common location for this folder is C:\Program Files\Winamp\Plugins.
Now you can enjoy this special speech format in the well-known audio player completely trouble-free.
Speex is an open-source compression standard created for speech.