Systems, methods, and devices for mixed voice and spread spectrum data signaling with enhanced concealment of data are disclosed. Audible artifacts may be reduced or suppressed in order to improve the audible quality of the sound. The distortion to the audio may be kept just below perceptibility, yet the data contained within the modulated signal is recoverable on the receiving side. The recovery of the data is robust to the impairments imposed by the communication channel. The disclosed systems, methods, and devices may be implemented in audio conferencing or video conferencing. Various embodiments of the present disclosure provide a data and voice mixer, which includes an improved spread spectrum data hiding transmitter. The transmitter may comprise a spreading encoder, a Phase Shift Keying (PSK) modulator, and a notch filter. A pseudo random switching pattern may be applied to a plurality of chip sequence generators in order to reduce or suppress an undesirable audible artifact. The transmitter may further comprise a phase randomizer operable to rotate the phase of the output of the spreading encoder by a pseudo random increment of approximately 45 degrees.