Methods and apparatus to audio watermarking and watermark detection and extracted are described herein. An example method includes receiving a media content signal, sampling the media content signal to generate samples, storing the samples in a buffer, determining a first sequence of samples in the buffer, determining a second sequence of samples in the buffer, wherein the second sequence of samples is of substantially equal length as the first sequence of samples, calculating an average of the first sequence of samples and the second sequence of samples to generate an average sequence of samples, extracting an identifier from the average sequence of samples, and storing the identifier in a tangible memory.

Methods and apparatus to audio watermarking and watermark detection and extracted are described herein. An example method includes receiving a media content signal, sampling the media content signal to generate samples, storing the samples in a buffer, determining a first sequence of samples in the buffer, determining a second sequence of samples in the buffer, wherein the second sequence of samples is of substantially equal length as the first sequence of samples, calculating an average of the first sequence of samples and the second sequence of samples to generate an average sequence of samples, extracting an identifier from the average sequence of samples, and storing the identifier in a tangible memory.

The present disclosure describes an efficient computer-implemented near-field communication system and method based on broadcasting audio signals for dynamically providing context-related additional content to a mobile device. In embodiments of the present invention, the additional content is mapped to specific audio watermarks and/or triggering commands which are encoded together into a digital signal. Based on continuously scanning the received background noise, an exactly defined frequency range and volume is dynamically selected for broadcasting the signal. Hence, the encoded digital signal is further modulated into an audio signal in the exactly defined frequency range. In embodiments of the present invention, the selected exactly defined frequency range for transmitting the audio signal may preferably be located in the ultrasound and/or infrasound frequency range. In case of transmitting infrasound signals, gyrosensors of the mobile device may be employed as audio signal receivers in embodiments of the present invention. Moreover, in further embodiments of the present invention, audio signal receiver of a mobile device such as gyrosensors or microphones may be switched on by transmitting a command via a wireless network such as Wifi or Bluetooth. Also the information about the selected frequency range and volume for broadcasting the audio signal may be provided to the mobile device via a wireless network in embodiments of the present invention. In response, an audio signal receiver of the mobile device may be tuned to the selected frequency range. The received audio signal is further processed on the mobile device so that the context-related additional content may be displayed and/or rendered.

Methods, apparatus, systems and articles of manufacture are disclosed for associating different watermarks detected in media. An example method disclosed herein includes determining whether a first watermark detected in a media signal is represented in a watermark data structure and associating the first watermark with a first media presentation record associated with a second watermark in response to the first watermark being associated in the watermark data structure with the second watermark. The example method further includes transmitting monitoring data including the first media presentation record to an audience measurement entity.

A broadcast receiving apparatus includes: a tuner configured to receive a transmission wave in which identification information is stored in a carrier, the carrier being modulated differently from a data carrier, a frequency band when the transmission wave is transmitted in an air being able to be identified by the identification information; and a controller. The controller is configured to identify a frequency band when the transmission wave is transmitted in the air by using the identification information contained in transmission wave received by the tuner.

A broadcast receiving apparatus includes: a tuner configured to receive a transmission wave in which identification information is stored in a carrier, the carrier being modulated differently from a data carrier, a frequency band when the transmission wave is transmitted in an air being able to be identified by the identification information; and a controller. The controller is configured to identify a frequency band when the transmission wave is transmitted in the air by using the identification information contained in transmission wave received by the tuner.

An apparatus for transmitting broadcasting signal using transmitter identification scaled by 4-bit injection level code and method using the same are disclosed. An apparatus for transmitting broadcasting signal according to an embodiment of the present invention includes a waveform generator configured to generate a host broadcasting signal; a transmitter identification signal generator configured to generate a transmitter identification signal for identifying a transmitter, the transmitter identification signal scaled by an injection level code; and a combiner configured to inject the transmitter identification signal into the host broadcasting signal in a time domain so that the transmitter identification signal is transmitted synchronously with the host broadcasting signal.

An apparatus for transmitting broadcasting signal using transmitter identification scaled by 4-bit injection level code and method using the same are disclosed. An apparatus for transmitting broadcasting signal according to an embodiment of the present invention includes a waveform generator configured to generate a host broadcasting signal; a transmitter identification signal generator configured to generate a transmitter identification signal for identifying a transmitter, the transmitter identification signal scaled by an injection level code; and a combiner configured to inject the transmitter identification signal into the host broadcasting signal in a time domain so that the transmitter identification signal is transmitted synchronously with the host broadcasting signal.

A first device listens for a communication token across an audio bandwidth covering a transmit frequency one or more audio frequency broadcasting device. The first device receives at least one token broadcast from the one or more broadcasting devices. The first device demodulates and decodes each received token. One or more computing devices validates each decoded token. The first device determines, based on the validating, a broadcasting device of the broadcasting devices with which to establish a communications channel. The one or more computing devices generates a response token based on the token received from the determined device. The first device broadcasts the generated response token in a response band of the determined device. The determined device demodulates decodes, and validates the token broadcast from the first device. Upon determining the token broadcast from the first device valid, the first device and the determined device establish a wireless communication channel.

Methods, systems, and apparatuses for presence detection are described herein. A first computing device may emit an inaudible audio signal. A second computing device may detect the inaudible audio signal. The second computing device may send an indication of detecting the inaudible audio signal. The first computing device may cause presentation of content to be modified based on the indication sent by the second computing device and a user profile associated with a user of the second computing device.