Abstract: An information management system includes: an audio signal acquisitor configured to acquire an audio signal representing a guide voice; a related information acquisitor configured to acquire related information that is related to the guide voice; an association manager configured to associate the related information acquired by the related information acquisitor for the guide voice with identification information that is notified to a terminal device upon emission of the guide voice corresponding to the audio signal; and an information provider configured to receive from the terminal device an information request including the identification information notified to the terminal device and to transmit to the terminal device the related information associated by the association manager with the identification information.

Abstract: A terminal device includes: a sound receiving device configured to receive a sound emitted according to an audio signal to generate a received-audio signal, the audio signal including an audio signal that represents a guide voice and including a modulated signal that includes identification information of the guide voice; an information extractor configured to extract the identification information from the received-audio signal generated by the sound receiving device; a transmitter configured to transmit an information request that includes the identification information extracted by the information extractor; an acquisitor configured to acquire, from among multiple pieces of related information that correspond to multiple pieces of identification information, a piece of related information that corresponds to the identification information in the information request; and an output device configured to output the piece of related information acquired by the acquisitor.

Abstract: A problem is to increase possibility of extracting data from sound in a system which transmits data using the sound as a transmission medium. Frames are transmitted while shifting the transmission timing among a plurality of frequency bands, whereby tolerance for multipath fading, noise mixing, or the like is obtained and improvement of a substantial transmission rate can be expected compared to a case where one frame is transmitted using only one frequency band. When selecting blocks forming a frame, since a block is selected under a condition that a time period necessary for collecting sound, on which the blocks to be selected are superimposed, becomes shorter, even if a phenomenon, in which a substantial rate of data transmission decreases, occurs, it becomes possible to suppress a decrease in rate.

Abstract: A problem is to increase possibility of extracting data from sound in a system which transmits data using the sound as a transmission medium. Frames are transmitted while shifting the transmission timing among a plurality of frequency bands, whereby tolerance for multipath fading, noise mixing, or the like is obtained and improvement of a substantial transmission rate can be expected compared to a case where one frame is transmitted using only one frequency band. When selecting blocks forming a frame, since a block is selected under a condition that a time period necessary for collecting sound, on which the blocks to be selected are superimposed, becomes shorter, even if a phenomenon, in which a substantial rate of data transmission decreases, occurs, it becomes possible to suppress a decrease in rate.