| 摘要 |
Portable apparatus comprising identification storing means associated with the apparatus, means for receiving an acoustic signal and converting the acoustic signal into a corresponding electric signal, a data processor for processing the electric signal to obtain audience survey data relating to the audio transmission, means for transmitting the identification information and the audience survey data. An audience survey station receives the transmitted data, identifies its user and stores the information in a database. An apparatus operable to interact with an audio transmission comprising recovering data encoded within audio transmission, and responding to the encoded data after a delay. |
