Methods and apparatus to audio watermarking and watermark detection and extracted are described herein. Disclosed example methods to decode a watermark from an audio signal include averaging a second sequence of audio samples stored in a buffer with a first sequence of audio samples stored in the buffer to determine an averaged sequence of audio samples, the second sequence of audio samples being related to the first sequence of audio samples based on a repetition period associated with watermark data of the watermark to be decoded. Disclosed example methods also include determining whether to enable a stacker. Disclosed example methods further include, in response to the stacker being enabled, decoding the watermark from the averaged sequence of audio samples, and in response to the stacker being disabled, decoding the watermark from the first sequence of audio samples.