Audio Watermarking Tools 2 (AWT2) of www.audiowatermarking.info are shareware utilities for embedding (and extracting) short data payload within audio streams (wave files). The tools are distributed as a package of GUI and console utilities running on Microsoft Windows 7/Vista/XP/NT/2000/Server, Apple Mac OS X and Linux; x86 and x64 versions of the binaries are available.
The watermark is highly robust. It survives almost all kinds of audio conversions such as transcoding using MP3, Ogg Vorbis and other lossy coders, acoustic coupling (transducing via air), effect processing from a simple EQ to an extreme dynamic range compression, reverberation, echo, and more.
AWT2 package is free to try. Evaluation (demo) version of AWT2 with limited functionality is available and can be downloaded absolutely free. Despite its limited functionality, the demo package offers enough flexibility to perform a variety of performance tests so that you can decide whether AWT2 suits your needs before buying a fully functional version.