Abstract: Methods and apparatus to analyze microphone placement for watermarks and signatures are disclosed. An example instructions cause one or more processors to at least determine a variance of a magnitude spectrum of a frequency band corresponding to a frequency spectrum of a first audio signal sensed with an audio sensor. The example instructions further cause the one or more processors to determine, based on the variance, a recovery rate associated with at least one of watermark detection or signature generation to be performed on a second audio signal to be sensed with the audio sensor.

Abstract: Methods and apparatus to identify an emotion evoked by media are disclosed. An example apparatus includes a synthesizer to generate a first synthesized sample based on a pre-verbal utterance associated with a first emotion. A feature extractor is to identify a first value of a first feature of the first synthesized sample. The feature extractor to identify a second value of the first feature of first media evoking an unknown emotion. A classification engine is to create a model based on the first feature. The model is to establish a relationship between the first value of the first feature and the first emotion. The classification engine is to identify the first media as evoking the first emotion when the model indicates that the second value corresponds to the first value.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed for affiliate interrupt detection. An example method disclosed herein includes determining whether a first time period of a first audio signal corresponds to a first affiliate interrupt period based on whether (1) a first type of watermark is detected in the first time period of the first audio signal, and (2) a second type of watermark is detected in the first audio signal outside the first time period but not in the first time period of the first audio signal, and determining whether the first time period of the first audio signal corresponds to the first affiliate interrupt period when watermarks are not detected in the first time period of the first audio signal based on comparison of first signatures with second signatures representing a corresponding first time period of a reference audio signal.

Abstract: Methods and apparatus to analyze microphone placement for watermarks and signatures are disclosed. An example apparatus includes a microphone. The example apparatus further includes a meter to convert a noise burst detected by the microphone to a digital signal. The example apparatus further includes a signal transformer to determine a frequency spectrum of the digital signal. The example apparatus further includes a processor to determine a variance of a magnitude spectrum of a frequency band corresponding to the frequency spectrum and determine, based on the variance, a recovery rate associated with at least one of watermark detection or signature generation to be performed on an audio signal detected by the microphone.

Abstract: Methods and apparatus for determining increasing robustness of media signatures are disclosed. An example apparatus includes a characteristic analyzer to determine a first difference between (A) a first characteristic of an audio signal at a first time and (B) a second characteristic of the audio signal at a second time.

Abstract: Methods and apparatus for pre-scaling media content to facilitate audience measurement are disclosed. An example method includes encoding a media content sample in accordance with a first encoding configuration and playing the encoded sample. The example method also includes attempting to detect the codes in the sample, and computing a ratio between the codes encoded in the sample and the codes detected when the sample is played.

Abstract: Methods, apparatus, systems and articles of manufacture (e.g., physical storage media) to detect media watermarks in magnetic field data are disclosed herein. Example media monitors disclosed herein include a magnetic field estimator to determine first magnetic field data, the magnetic field estimator in communication with a magnetometer. Disclosed example media monitors also include a correlator to correlate the first magnitude field data with a reference sequence to determine second magnetic field data. Disclosed example media monitors further include a watermark decoder to process the second magnetic field data to detect an audio watermark encoded in an audio signal.

Abstract: A method for generating a signature is disclosed. As part of the method, a first number of bits are identified in respective rows of an audio signature matrix that are determined to be the strongest bits in the row, bits of the audio signature matrix are replaced with respective cells having values depending on whether the respective bits are included in the first number of bits, a set of uniformly distributed numbers are generated within a range of numbered locations corresponding to cells of the audio signature matrix; numerical distances are determined, from respective numbers in the set of uniformly distributed numbers, to the numbered locations of the matrix, associated with nearest occurrences of a first value. A set of integers is generated based on the distances.

Abstract: Methods and apparatus for performing variable block length watermarking of media are disclosed. Example apparatus include means for evaluating a masking ability of a first audio block; means selecting a first frequency to represent a first code, the means for selecting to (i) select the first frequency selected from a first set of frequencies that are detectable when performing a frequency transformation using a first block length, but are not detectable when performing a frequency transformation using a second block length, and (ii) select a second frequency to represent a second code, the second frequency selected from a second set of frequencies that are detectable when performing a frequency transformation using the second block length; means for synthesizing a first signal having the first frequency with the masking ability of the first audio block; and means for combining the first signal with the first audio block.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed for media crediting and, more particularly, methods and apparatus of media device detection for minimally invasive media meters. An example apparatus disclosed herein to detect media devices presenting media comprises a cluster generator including circuitry to generate a cluster of media locations based on media identifying information received from a presentation of media at an unidentified media device, a media device including circuitry determiner to determine media devices available at the media locations in the cluster of media locations, and a cluster based media device identifier including circuitry to identify the unidentified media device based on (1) the media devices available at the media locations in the cluster of media locations and (2) an identity of a media device determined to be available in a majority of media locations in the cluster of media locations.

Abstract: Apparatus, systems, methods, and articles of manufacture related to end-point media watermarking are disclosed. An example device includes a media receiver to receive a media signal, a watermark generator to generate a watermark, a trigger to activate the watermark generator to generate the watermark based on an external input, an encoder to encode the media signal with the watermark to synthesize an encoded media signal, a media output to render the encoded media signal.

Abstract: Methods and apparatus to present supplemental media on a second screen are disclosed. An example method includes establishing a connection between a digital media device and a computing device based on information identifying the computing device and, in response to establishing the connection, receiving, at the computing device, a first notification from the digital media device including a location of supplemental media; accessing the supplemental media; and in response to accessing the supplemental media, sending a second notification that the supplemental media has been accessed, the second notification to enable media skipping on the digital media device.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed for watermarking using starting phase modulation. An example apparatus includes memory, and processor circuitry to execute instructions to at least determine a first analyzed phase value for a watermark component of a watermarked media signal at a first time, determine a sum of differences for analyzed phase values with respect to a first one of a plurality of possible starting phase values, the analyzed phase values associated with the watermarked media signal, the analyzed phase values including the first analyzed phase value, in response to the sum of differences satisfying a threshold, decode a first data value corresponding to the first one of the possible starting phase values, and determine a watermark payload based on the first data value.

Abstract: Methods and apparatus to identify an emotion evoked by media are disclosed. An example apparatus includes a synthesizer to generate a first synthesized sample based on a pre-verbal utterance associated with a first emotion. A feature extractor is to identify a first value of a first feature of the first synthesized sample. The feature extractor to identify a second value of the first feature of first media evoking an unknown emotion. A classification engine is to create a model based on the first feature. The model is to establish a relationship between the first value of the first feature and the first emotion. The classification engine is to identify the first media as evoking the first emotion when the model indicates that the second value corresponds to the first value.

Abstract: Methods, apparatus, systems and articles of manufacture (e.g., physical storage media) to detect media watermarks in magnetic field data are disclosed herein. Example media monitoring apparatus disclosed herein include means for transforming magnitude values of magnetic field data to a frequency domain to determine transformed magnetic field data, the magnetic field data associated with a first sampling rate, the magnetic field data obtained from a sensor. Disclosed example media monitoring apparatus also include means for detecting an audio watermark in a portion of the transformed magnetic field data associated with a first frequency, the audio watermark encoded in an audio signal, the audio watermark to have a frequency component associated with a second frequency different from the first frequency, the first frequency to be aliased relative to the second frequency based on the first sampling rate.

Abstract: Disclosed example apparatus select a first frequency from a set of frequencies based on a first symbol in a code, and select a first block size based on the first symbol and the code, a combination of the first block size and the first frequency to represent the first symbol. Disclosed example apparatus also synthesize a code frequency according to the first block size and the first frequency. Disclosed example apparatus further embed the code frequency in a first block of input audio samples of the audio having the first block size to form a block of encoded audio samples encoded with the first symbol, the code frequency and the first block of input audio samples to overlap in time.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed for media crediting and, more particularly, methods and apparatus of media device detection for minimally invasive media meters. An example apparatus disclosed herein to detect media devices presenting media comprises a cluster generator to generate a cluster of media locations from a reference population of media locations based on media identifying information received from a presentation of media at an unidentified media device at a first media location, a media device determiner to determine media devices available at the media locations in the cluster of media locations, a cluster based media device identifier to identify the unidentified media device based on the media devices available at the media locations in the cluster of media locations, and a media device report generator to generate a report on the identity of the unidentified media device.

Abstract: Methods, apparatus, systems and articles of manufacture to count people in an audience are disclosed. An apparatus includes a location determiner to determine a location of a portable device was outside of a media exposure environment, and a proximity determiner to determine a person was in proximity to the portable device. The apparatus also includes a presence detector to: generate first presence information based on the location of the portable device and the proximity of the person to the portable device, the first presence information to indicate that the person was absent from the media exposure environment; compare the first presence information to second presence information collected by a people meter; and, when the second presence information indicates the person was present in the media exposure environment, modify the second presence information based on the first presence information.

Abstract: Methods and apparatus for determining increasing robustness of media signatures are disclosed. An example apparatus includes a characteristic analyzer to determine a first difference between (A) a first characteristic of an audio signal at a first time and (B) a second characteristic of the audio signal at a second time.

Abstract: Methods, apparatus, systems and articles of manufacture are disclosed for watermarking using starting phase modulation. An example method disclosed herein includes calculating a first instantaneous phase value for a first watermark component of a watermarked media signal at a first time, calculating a second instantaneous phase value for a second watermark component, determining a first sum of differences for the first and second instantaneous phase values relative to a first possible starting phase value, determining a second sum of differences for the first and second instantaneous phase values relative to a second possible starting phase value, selecting a corresponding one of the first possible starting phase value or the second possible starting phase value to be a starting phase value, decoding a bit value corresponding to the starting phase value, determining a payload based on the bit value and a symbol represented by watermark components.