A data embedding device has: a phase adjusting unit for adjusting a phase of an acoustic signal in accordance with a frame unit in which arbitrary transmission data is to be embedded; and a combining unit for embedding the transmission data in the phase-adjusted acoustic signal. A data extraction device has: a removing unit for removing a low frequency component from an acoustic signal in which arbitrary transmission data is embedded, to generate a low-frequency-removed acoustic signal; a synchronizing unit for synchronizing the low-frequency-removed acoustic signal generated by the removing unit, in accordance with a frame unit used when the transmission data was embedded in the acoustic data; and an extraction unit for extracting the transmission data from the low-frequency-removed acoustic signal synchronized by the synchronizing unit.