This isn't portable software in any of the supported platforms since it is basically a custom audio driver -- and it even requires 'root' privileges on Android -- but the benefits far outmatch the nuisance. On Windows, ViPER also requires DotNET (v2.0) for its control panel.
http://vipersaudio.com/blog/ author wrote:ViPER's Audio is an audio enhancing software to provide everyone with better audio experiences in various platforms such as smartphones and PCs.
ViPER4Windows latest release (currently v1.0.5) can be downloaded from http://vipersaudio.com/blog/?page_id=48.
Lastly, if you're interested in the Android side, this article is a good as any other place to start: