METHOD AND DEVICE FOR DETERMINING INFORMATION INSERTED INTO AN AUDIO SIGNAL AND METHOD AND DEVICE FOR INSERTING INFORMATION INTO AN AUDIO SIGNAL

摘要

In a method for determining information inserted into an audio signal, an audio signal-specific characteristic, e.g. the psychoacoustic masking threshold, of the audio signal is assessed (13), which indicates the energy progression of the inserted information. The spectral representation of the audio signal is then pre-processed (12) based on the characteristic. The now pre-processed audio signal then undergoes a correlation in order to extract the information once again. The smoothing of the highly varying energy of the audio signal leads to a more simple and improved correlation and thus to improved extraction results. The smoothing can be achieved by suppressing tonal frequency bands or by inverse manipulation using the psychoacoustic masking threshold or by using both measures. This also enables a corresponding modification in a device for inserting information into the audio signal whereby resulting in no disturbing noise whatsoever being introduced into tonal frequency bands of the audio signal thereby risking no losses in the quality of the audio signal.