In this paper, we present a unified algorithm for phase and magnitude speech spectra data hiding. The phase and the magnitude speech spectra are concurrently investigated to increase the capacity and the security of the embedded information. The proposed algorithm in this paper is based on finding secure spectral embedding areas in wideband magnitude speech spectrum. Our approach exploits these areas to hide data in both speech components (i.e., phase and magnitude). The embedding locations and hiding capacity are defined according to a controlled acceptable distortion in the magnitude spectrum. The latter is expressed as a set of parameters controlled by the sender. Consequently, the hiding capacity and the locations of concealed data change for each data communication instance to further prevent malicious intrusions. Objective results show that the presented algorithm in this paper secures hidden data and achieves interesting tradeoffs between the hiding capacity and the speech quality. Copyright © 2013 John Wiley & Sons, Ltd.