Methods, apparatus, and articles of manufacture are disclosed in which auxiliary information is added to or removed from an audio signal. In one example, the information may be added to the audio signal using at least two frequencies that are dictated by two different frequency transformation block sizes, such that the two frequencies are not fully visible when an incorrect block size is used to perform a frequency transformation. Additionally, in another example, a decoder may compensate for time and frequency affects caused by removing old samples and adding new samples, which, in one example, alleviates the need to perform repeated frequency transformation using different frequency transformation block sizes. Other examples are described.