This paper is concerned with hiding secret data in audio media file (.WAV). When
performing data hiding in audio, one must exploit the weaknesses of Human Auditory System
(HAS), while at the same time being a ware of the extreme sensitivity of this system. This
hiding method is oriented to embed the secret data such that it is capable of surviving against
modifications produced by MP3 compression standard. Statistical and analytical
investigations are performed to assess the variations which may occur in the WAVE audio
when it is subjected to MP3 compression. Features of speech signal are exploited (Voiced-
Unvoiced segments) for embedding the secret data. Hiding is attempt by shortening or
elongating the unvoiced blocks of audio file (cover) data. To support the immunity of the
proposed hiding system, an encryption method is added to the proposed hiding system.