Abstract: A monitoring device (1) comprising a basic set of audience research data retrieval units (7, 9) which are compatible with a broad range of AV appliances reproducing AV contents like TV sets (3). The data retrieval units are a audio watermark retrieval unit (9) and an audio signal sampling unit (7). For easy adaptation to particular AV installation, the monitoring device (1) is provided with internal and external connectors so that specialized modules can be integrated.

Abstract: A monitor (10) for capturing audience research data from a computer (2-8) having AV presentation capability is attached to the computer by a connector (12). The connector (12) allows to download software stored in the monitor (10), The software watches AV signals played back by the computer and furnishes data the AV signals to the monitor (12). Optionally, or instead of the software, the data detectable on the connector (10) may be analyzed if they relate to AV signals played back.

Abstract: Disclosed is an arrangement for determining a chronological acceptance of spaced-apart devices, comprising at least one transmitter unit which is disposed on each device and from which a signal that identifies said device and has a predefined range can be transmitted. Several personal apparatuses are provided that are to be carried by one respective person and are fitted with a receiver for the signals and a device memory for storing data contents of the emitted signals during a given interval. The range of each transmitter unit defines a respective transmission range. The transmission range and a receive sensitivity of the receiver are adjusted to each other in such a way that no data can be received if the device is located outside a typical zone of attention or perception of humans relative to the personal apparatus carried by the person.