Audio Steganography

A subject embeds data within an audio file or audio stream so that the concealed information is carried inside apparently legitimate sound content. The audio may continue to play normally, while modifications to the underlying samples, frequency components, timing, phase, or file structure contain a hidden payload.

Audio steganography may be used to conceal sensitive organizational data within music, voice recordings, podcasts, meeting recordings, sound effects, or other audio content before the file is transferred through an approved or commonly used communication channel. The subject may select audio because normal variations in sound, background noise, and compression can make small alterations difficult to identify through ordinary review.

Methods may include modifying the least significant bits of audio samples, altering phase or frequency characteristics, inserting information into low-audibility ranges, using echo-based encoding, or appending data within fields not required for normal playback. The concealed payload may also be encrypted before embedding, preventing recovery of its contents even where investigators identify that steganography has been used.