A method and a system for augmenting an audio feed for inclusion of data therein suitable for determining an identity of a human assessor are provided. The method comprises: receiving the audio feed; receiving an indication of identity of the human assessor to whom the audio feed is to be transmitted, the indication of identity being representable by a unique sequence of bits; generating, based on the unique sequence of bits, an identity watermark associated with the human assessor to be included in the audio feed to generate an augmented audio feed, by modifying the audio signal to have predetermined energy level at each of at least two different frequency levels to indicate presence of the given bit of the unique sequence of bits associated with the human assessor in the augmented audio feed; and transmit the augmented audio feed to an electronic device associated with the human assessor.

Methods and apparatus to perform audio watermarking and watermark detection and extraction are disclosed. Example apparatus disclosed herein are to select frequency components to be used to represent a code, different sets of frequency components to represent respectively different information, respective ones of the frequency components in the sets of frequency components located in respective code bands, there being multiple code bands and spacing between adjacent code bands being equal to or less than the spacing between adjacent frequency components in the code bands. Disclosed example apparatus are also to synthesize the frequency components to be used to represent the code, combine the synthesized frequency components with an audio block of an audio signal, and output the audio signal and a video signal associated with the audio signal.

Methods and apparatus to perform audio watermarking and watermark detection and extraction are disclosed. Example apparatus disclosed herein are to select frequency components to be used to represent a code, different sets of frequency components to represent respectively different information, respective ones of the frequency components in the sets of frequency components located in respective code bands, there being multiple code bands and spacing between adjacent code bands being equal to or less than the spacing between adjacent frequency components in the code bands. Disclosed example apparatus are also to synthesize the frequency components to be used to represent the code, combine the synthesized frequency components with an audio block of an audio signal, and output the audio signal and a video signal associated with the audio signal.

Systems and methods for data communication using audio patterns are described. The methods include encoding a message into an audio pattern, mixing the audio pattern with an audio content to obtain a mixed audio content, wherein the audio pattern is inaudible in the mixed audio content, and transmitting the mixed audio content.

Systems and methods for data communication using audio patterns are described. The methods include encoding a message into an audio pattern, mixing the audio pattern with an audio content to obtain a mixed audio content, wherein the audio pattern is inaudible in the mixed audio content, and transmitting the mixed audio content.

Example apparatus to improve timestamp transition resolution of watermarks are disclosed. A disclosed example apparatus is to decode timestamps in respective ones of detected watermarks, estimate a first transition window indicative of a transition between a first time period to a second time period based on a first one of the timestamps and a second one of the timestamps, and when the first transition window does not satisfy a threshold, estimate a second transition window indicative of a transition between the second time period and a third time period based on the second one of the timestamps and a third one of the timestamps. The disclosed example apparatus is also to determine a first mapped transition window based on an intersection of the first transition window and the second transition window, and set the first mapped transition window as a reference time transition window for subsequent time periods.

Example apparatus to improve timestamp transition resolution of watermarks are disclosed. A disclosed example apparatus is to decode timestamps in respective ones of detected watermarks, estimate a first transition window indicative of a transition between a first time period to a second time period based on a first one of the timestamps and a second one of the timestamps, and when the first transition window does not satisfy a threshold, estimate a second transition window indicative of a transition between the second time period and a third time period based on the second one of the timestamps and a third one of the timestamps. The disclosed example apparatus is also to determine a first mapped transition window based on an intersection of the first transition window and the second transition window, and set the first mapped transition window as a reference time transition window for subsequent time periods.

Embodiments provide an apparatus for providing a fingerprint of an input signal, wherein the apparatus is configured to determine intensity values for a plurality of time-frequency regions of the input signal, wherein the apparatus is configured to compare the intensity values associated with different time-frequency regions of the plurality of time-frequency regions, to obtain individual values of the fingerprint based on the comparison of intensity values associated with two time-frequency regions.

Embodiments provide an apparatus for providing a fingerprint of an input signal, wherein the apparatus is configured to determine intensity values for a plurality of time-frequency regions of the input signal, wherein the apparatus is configured to compare the intensity values associated with different time-frequency regions of the plurality of time-frequency regions, to obtain individual values of the fingerprint based on the comparison of intensity values associated with two time-frequency regions.

Methods, apparatus, systems, and articles of manufacture to improve watermark detection in acoustic environments are disclosed. An example apparatus includes at least one memory, instructions in the apparatus, and processor circuitry to execute and/or instantiate the instructions to encode a first symbol in a media file at a first symbol position on a first encoding layer of a multilayered watermark, and encode a second symbol in the media file at a second symbol position on a second encoding layer of the multilayered watermark, the first encoding layer and the second encoding layer including a plurality of symbol positions, one or more of the plurality of the symbol positions on at least one of the first encoding layer or the second encoding layer to be empty.