Abstract: Methods and apparatus for encoding and decoding information in broadcast or recorded segment signals are described. In certain embodiments, an audience monitoring system encodes identification information in the audio signal portion of a broadcast or recorded segment using spread spectrum encoding. A personal monitoring device receives an acoustically reproduced version of the broadcast or recorded signal via a microphone, decodes the identification information from the audio signal portion despite significant ambient noise, and stores this information, automatically providing a diary for the audience member which is later uploaded to a centralized facility. A separate monitoring device decodes additional information from the broadcast signal, which is matched with the audience diary information at the central facility.

Abstract: Methods and systems for measuring and gathering data relating to publication usage by participants in publication readership studies. Some methods and systems employ portable monitors carried by participants of the studies along with publications fitted with various devices, such as piezoelectric transducers, RFID tags and others devices and circuits.

Abstract: Systems and methods are provided for gathering audience measurement data relating to exposure of an audience member to audio data. Audio data is received in a user system and is then encoded with audience measurement data. The encoded audio data is reproduced by the user system, picked up by a monitor and decoded to recover the audience measurement data.

Abstract: Systems and methods are provided for gathering audience measurement data relating to receipt of and/or exposure to audio data by an audience member. Audio data is monitored to detect a monitoring code. Based on detection of the monitoring code, a signature characterizing the audio data is extracted.

Abstract: An encoding system for encoding a first ancillary code in media data and monitoring for reception of a second ancillary code that has a higher priority than the first ancillary code, such that upon detection of the higher priority ancillary code the encoding system modifies a characteristic and/or characteristics of the first ancillary code.

Abstract: Apparatus and methods for including a code having at least one code frequency component in an audio signal are provided. The abilities of various frequency components in the audio signal to mask the code frequency component to human hearing are evaluated and based on these evaluations an amplitude is assigned to the code frequency component. Methods and apparatus for detecting a code in an encoded audio signal are also provided. A code frequency component in the encoded audio signal is detected based on an expected code amplitude or on a noise amplitude within a range of audio frequencies including the frequency of the code component.

Abstract: Systems, methods and devices for gathering data concerning exposure of predetermined survey participants to billboards are provided. A portable transmitter is arranged to transmit a signal containing survey participant data, and a receiver located proximately to the billboard serves to receive the signal transmitted by the transmitter.

Abstract: Systems and methods are provided for decoding a message symbol in an audio signal. This message symbol is represented by first and second code symbols displaced in time. Values representing the code signals are accumulated and the accumulated values are examined to detect the message symbol.

Abstract: A method and system for reliably detecting encoded messages included in audio media data in varying acoustic environments, where only a portion of the predetermined message may have been received or detected.

Abstract: Systems and methods are provided for encoding and decoding multiple messages in audio data. The messages each comprise a sequence of message symbols each comprising a combination of substantially single-frequency components. At least some of the message symbols in one of the messages coexist with at least some of the symbols of another one of the messages along a time base of the audio data.

Abstract: Apparatus and methods for including a code having at least one code frequency component in an audio signal are provided. The abilities of various frequency components in the audio signal to mask the code frequency component to human hearing are evaluated and based on these evaluations an amplitude is assigned to the code frequency component. Methods and apparatus for detecting a code in an encoded audio signal are also provided. A code frequency component in the encoded audio signal is detected based on an expected code amplitude or on a noise amplitude within a range of audio frequencies including the frequency of the code component.