Methods of steganographically encoding auxiliary data into audio and decoding the auxiliary data. In an encoding method, a processor maps the auxiliary data to samples in the audio data. A processor modifies the mapping of the auxiliary data to the samples over time. A processor modifies a feature of the samples of the audio data to which the code signals are mapped to convey the auxiliary data substantially imperceptibly in the audio data. In a decoding method, a processor performs decoding of a multibit auxiliary code embedded in an audio signal. A processor decodes code values of the auxiliary code from two or more different portions of the audio signal, each having the multibit auxiliary code. A processor combines the code values decoded from the two or more different portions of the audio signal to determine the code values of the auxiliary code.