DE4420075C2 - Devices and methods for recording the use of radio programs - Google Patents

Description

The present invention relates to devices and Procedure for registering the use of radio programs.

It is of great interest to have demoscopic information about how far people are from each Programs offered by the various broadcasters Make use. In the following, broadcasting denotes the Broadcasting of radio and television programs via distribution  suitable transmission media of all kinds, for example via terrestrial antenna, via satellite or via cable. These For example, information is of great importance when it has to be assessed how many people with commercials how well a program can be achieved at certain Target groups "arrives", or what program usage behavior show certain target groups. To such information received different ways suggested. So it is known from DE 33 42 949, for the purpose an additional device for demoscopic television viewer research to a number of test subjects on the television install, which detects which TV channel that TV set in which periods is tuned. This will the tuning voltage of the television tuner measured and from it the set program is closed.

DE 26 08 508 describes a device for detecting and Output information about TV turn-on behavior known by television participants, which as well as that Device described above as an additional device on the television is installed. To the identity of the received program determine the additional device Station acquisition part on, with a microphone with a Amplifier, a tuning unit that is connected to the input side Antenna is connected, and a comparison device, which the output signal of the amplifier with one of the Tuning unit supplied sound signal all over the Antenna of received stations is compared.

From FR 2555383 A1 a device is known that a Has microphone and a receiver. The one from the microphone accepted acoustic signals and those from the receiver Output signals are digitized and together correlated to determine which one is from the recipient  received transmitter the acoustically recorded sound signal corresponds. This information is shared with Time information for later central evaluation saved. From this document it is also known the signal path from the microphone to the comparison device partially train over a radio link to allow that when monitoring multiple radios only a single facility is required to support the Carries out comparison. Similar stationary devices are known from FR 2676151 A1 and WO 88/10540 A1.

An essential aspect when recording the Program usage behavior of test subjects is, however Question whether the test person also the set program actually perceives. Does a test person switch that Receiver on, but then leaves, for example the room in which the device is located, this becomes State of the known detection devices incorrectly registered as a program use, which leads to a Falsification of the detection result. if the Test person on the other hand uses a radio, which not with one  Detection device is equipped, such actual program uses with those from the named Documents known devices can not be detected.

From DE 42 38 681 A1 a device is known which on Body of a test person can be worn, for example in the form of a wristwatch. This device contains a Microphone, an evaluation circuit and a memory that Stores identification signals together with time information. These Device does not speak to the real thing Sound program signal on, but on contained therein Identification signals that are characteristic of the received transmitter and are added to the sound program signal.

WO 9111062 describes a mobile device for detecting the Use of radio programs known to a receivable transmitter tunable receiver, a microphone and comprises a comparison device. To the presence of the Special transponders are provided, that the listeners carry with them on the body.

From US 4 955 070 one is wearable on a person's body designed device for detecting the use of Broadcast programs known, with a microphone for receiving audible acoustic signals and output of one acoustic signal corresponding reference signal, and with a receiver for receiving and demodulating radio signals. Finally, there are means for comparing that from that Microphone supplied reference signal with that of the Receiver supplied useful signal and output a respective comparison result.  

The known from the publications mentioned above However, devices are unable to provide the actual To record the usage behavior of test persons in an unadulterated manner, if the test person uses radio programs that are available via cable be distributed or the reception of terrestrial (via Antenna) broadcast radio programs due to poorer Reception is difficult locally and is more complex Antenna requires as provided in the mobile detection part is.

Accordingly, it is the object of the present invention that Device and the method of the type mentioned for Capture the use of broadcast programs offered so improve that the actual usage behavior of too selected test subjects for demoscopic purposes Inclusion of cables distributed or via antenna largely broadcast terrestrial radio programs can be recorded unadulterated.

This object is achieved as in the Claims 1, 2, 11 and 27 is given.

To allow that even distributed over cables Program offers to be included in the recording points a detection device according to the invention a sensor for Receiving a local program signal from a stationary converter device is broadcast.

The stationary converter device is attached to the cable connected to a cable received Broadcast program signal into the local program signal convert and send it out so that it is local, for example in the home of a test person Body of the test person to be worn, d. H. mobile Receiving device by means of the sensor and can be processed.  

This arrangement of stationary device and mobile acquisition part also suitable for terrestrial Program offers broadcast via antenna in the recording with whose direct reception due to poor Reception is difficult locally and is more complex Antenna required than in the mobile detection part is provided. In this case, the stationary device additionally or alternatively to the connection to the cable also to a suitable antenna connected. According to the Comparison between useful signal and reference signal in the am Body of the test subject's portable sensing device, (Claims 1 and 11), or in the stationary Converter device (claims 2 and 27). In the latter Case can affect the data transmission capacity of the local Program signal lower requirements are made. In In this case, the local program signal, which the Result carries from the stationary converter device as far broadcast locally as the sound signal from the Radio is broadcast, which the test person for Use of bound program signals used. Accordingly the mobile detection device registers the use of a bound program signal in this case only if the test person receives the sound signal of the corresponding program actually perceives.

Advantageous refinements of the invention result from the subclaims.

In order to record the program usage behavior of a test person, the detection device can be designed so that the Demodulation devices include tuning devices, periodically programs whose use is to be recorded, to tune and a corresponding sequence of useful signals according to the voting order To provide comparison facilities. It is from the  Demodulation devices demodulate each program as long as as needed to make a comparison with that on acoustic signal received signal before the next program is continued. To the To increase detection efficiency, the process of Voting will be interrupted if a positive Comparative result was obtained. If the following cycle the program is started, which is ultimately a positive one Comparison result offered, a further reduction can be made of the necessary comparisons. If in Periods between acquisition cycles the device in an energy saving mode (stand by) can be switched on this reduces the energy consumption of the device will.

Especially when a large number of programs can be tuned by previewing several, in parallel working voting facilities in the stationary Device and / or in the mobile detection device Acceleration of the tuning process can be achieved. Here can the multiple tuning devices preferably to the Program signals are synchronized in parallel at the same time, Which  are different, but essentially the same Carry useful signal.

It is then advantageous to provide a selection device which are those of the tuning devices working in parallel coordinated program signals with essentially identical Useful signal on alternative frequencies on their respective Receiving quality or received signal strength examined, the selects the strongest program signal and this the Demodulation devices supplies.

The assignment of the program signals which have the same useful signal wear and vote in parallel by the voting facilities are in a mapping table in memory can be stored or this assignment, if by the Broadcasters offered, additional information taken that are carried by the program signals. For example, the RDS signal provides information about this what alternative program signal frequencies a useful signal is broadcast.

If the mobile detection device together with a stationary device which sends a local program signal the mobile detection device sends, uses, so can the demodulation devices over the Local program signals received in sensor devices include the query sequence of the program signals.

The stationary device can be in one of the mobile Device correspondingly tuning and Include demodulation devices which are via cable or stationary antenna programs received cyclically tune and the respective, demodulated useful signals or characteristics relevant to the comparison Useful signals together with program identification information by means of the local program signal to the mobile device transfer.  

The mobile detection device and the stationary device can be designed as identical devices, depending on Type of use (mobile / stationary) are configurable.

The detection device according to the invention can have a memory in which the results of the acquisition process get saved. It is beneficial Program identification information, for example a by means of a decoder in the detection device can be provided, decoded transmitter identification and / or Program content identifier together with respective Comparison results and time information in the memory to file. The station identifier, program content identifier, Station information, etc. can be sent to the RDS Signal can be taken.

For a further increase in the reliability of the Result, it is particularly advantageous to use the mobile Detection device wearable on the skin of the test person to design and with a skin temperature, optical or electrical sensor, which indicates whether the Test person in the period of recording a program usage Detection device also actually carries. Alternatively or in addition, the device can for this purpose with a Accelerometer to be equipped. The one or the Information received from sensors can also be stored in memory be filed and give along with related Time information to what extent the Acquisition results apply and / or whether the test person receives the Detection device over the notified period too has actually worn.

To carry the test device for the test person can make mobile appear attractive Detection device further useful for the test person Include functions, for example in the form of a Display the time of day in conjunction with the Skin temperature, optical or electrical sensor  physiological data of the test person, such as heartbeat, Show skin circulation, temperature etc. as a piece of jewelry be formed, and / or by means of the acceleration sensor Count steps.

The devices for receiving acoustic signals can include an amplifier that is a human ear has simulated amplification characteristics.

According to one aspect, the comparison of the first signal with the useful signal in the frequency domain. As a result of that both signals are transformed into the frequency domain, and phase information disregarded in the comparison is, influences of runtime differences, which can between the acoustically received by the mobile detection part Signal and the useful signal result on the comparison result be eliminated.

According to a further aspect, the comparison method uses a cross correlation between the acoustically received Reference signal and the useful signal to determine whether these signals are to be regarded as the same. The Cross correlation relationship between the compared signals formed in the frequency domain to the required Reduce computing effort. Then this can be done in Time domain or in the frequency domain to a maximum to be examined. Has a sufficiently large maximum the compared signals are considered equal.  

This method is advantageous in that it is one hand insensitive to runtime differences between the comparative signals is because this is just the location the maximum of the cross correlation functions on the Influence time axis, and on the other hand against background noise, which are recorded acoustically via the microphone with However, the useful signal are not correlated.

The present invention will be described in more detail below described with reference to the accompanying drawings, which show:

Fig. 1 shows a first embodiment to explain the technical background of the invention;

Fig. 2 is a block diagram of the detecting apparatus according to the first embodiment;

Fig. 3 shows a second embodiment of the invention;

Fig. 4 shows an embodiment of a transmitted signal by means of a local program information signal;

Fig. 5 is a block diagram of an embodiment of a stationary or conversion device according to the present invention;

Fig. 6 is a block diagram of the detection device according to the second embodiment of the invention;

Fig. 7 is a block diagram of the detection device according to a third embodiment of the invention;

Fig. 8 is a block diagram of the detecting device according to a fourth embodiment of the invention;

Fig. 9 is a first embodiment of a recording strategy;

Fig. 10 shows a second embodiment of a detection strategy;

FIG. 11 is an embodiment of a storage routine; and

Fig. 12 shows an embodiment of a membership function.

Fig. 1 shows schematically a first embodiment to explain the technical background. In this figure, 1 denotes a device for detecting the use of radio programs, 2 a conventional radio receiver, 3 an evaluation device, 3 a a first interface, which is part of the evaluation device, 3 b a second interface, which is part of the detection device, 5 denotes one Antenna device, which is part of the device for detecting the use of radio programs, 6 designates the antenna of the radio receiver. 7 denotes a microphone, which is part of the detection device, and 8 denotes a loudspeaker device, which is part of the radio receiver 2 . Finally, 9 designates a radio transmitter which broadcasts radio program signals in the form of terrestrially freely propagating high-frequency signals which carry a modulated useful signal. Here and in the following, the term "broadcasting" denotes both radio and television.

The radio program signal emitted by the radio transmitter 9 is received by the antenna 6 19 of the radio receiver 2 in a known manner, demodulated and in this way a sound signal is emitted via the loudspeaker device 8 . This acoustic signal is perceived by the radio subscriber. At the same time, this acoustic signal is picked up by the microphone 7 of the detection device 1 , which the radio subscriber can wear on his body. Independent of the radio receiver used by the test person, independent receiving devices in the detection device receive program signals offered for use via the antenna 5 of the detection device. If the detection device is designed to be wearable on the wrist, the antenna 5 can be accommodated in the bracelet. The detection device compares the program content, ie the useful signal modulated onto the received program signal with the acoustic signal received via the microphone 7 . Because the test person carries the detection device with him, the acoustic signal picked up by the microphone 7 corresponds to the acoustic signal perceived by the test person. Through the comparison of the useful signal by comparison devices in the detection device 1 with a reference signal derived from the acoustic signal received via the microphone 7 in the detection device, the detection device according to the invention is able to determine whether the test person does this from the detection device received program, ie perceives the content of the useful signal.

One in the detection device of this embodiment provided storage device can store, for. B. too what time the test person received a certain program Has. In addition, the detection device is able to by means of a tuning device, several different ones To receive and demodulate program signals and the received useful signals with the via the acoustic path received reference signal to compare. In the Storage device is in addition to the time information Program identification information filed, so that these Information reveals when the test person which program has used. This program identification information can, depending on Need to include one or more of the following: Broadcasting company (e.g. Bayerischer Rundfunk), program name (e.g. BR3), carrier frequency of the program signal, Program content identifiers (e.g. text contribution, music, news,  etc.), as far as content identifiers are offered by the transmitting station will.

For evaluation, the stored data are transferred from the memory of the detection device 1 via the interface 3 b, which for reasons of miniaturization is preferably an infrared interface, to an evaluation device 3 . A personal computer (PC), for example, can serve as the evaluation device. The data obtained in this way regarding the program use of the respective test person can then be sent to a demoscopic evaluation.

FIG. 2 shows a block diagram of the functional groups of the detection device 1 according to the first exemplary embodiment. The broadcast program signal received via the antenna 5 of the detection device 1 is fed to a demodulator 12 , which is used to recover the useful signal modulated onto the program signal. This useful signal is bandpass filtered at the output of demodulator 12 . Spectral components of the useful signal filtered out in this way, for example in the range from 300 Hz to 3 kHz, are then converted into a sequence of digital samples using a first analog / digital converter 15 . By means of a decoder 11 , identification information is also extracted from the program signal, which identifies the received program, the reception frequency, program contents, etc. If the received program includes an RDS signal, the decoder 11 decodes this signal and outputs the identification information contained therein. If the received program signal does not include such an information service, the decoder 11 outputs the reception frequency, ie the carrier frequency of the program signal, as identification information.

The microphone 7 of the detection device 1 converts the received sound into an electrical signal, which is amplified by a microphone amplifier 13 . The microphone amplifier 13 has an automatic gain control function which simulates the sensitivity characteristic of the human ear. The output signal of the amplifier 13 is bandpass filtered in the same way as the useful signal obtained from the demodulator 12 and the reference signal thus obtained is converted in a second analog / digital converter 14 into a sequence of digital samples. The output signals of the first and second analog / digital converter, as well as the program identifier decoded by the decoder 11, are fed to a digital signal processing device 16 . This signal processing device 16 comprises a digital signal processor device 16 a, a memory device 16 b, which includes RAM areas, ROM areas and non-volatile memory, a clock function 16 c and a control device 16 d, which controls the entire sequence of the functions of the detection device 1 . The functional units in the signal processing device 16 can be designed as separate circuits or as a programmed circuit unit.

The digital signal processor 16 a detects characteristic structures in the digitized reference signal and in the digitized useful signal, compares these structures and, depending on the result of this comparison, determines whether the useful signal and the reference signal are to be regarded as matching. If positive, this comparison result is stored in the memory 1 b together with the current time supplied by the clock 16 c and the identification information supplied by the decoder 11 . In this exemplary embodiment, temporal sections of the reference signal and the useful signal are used for the comparison, which have a duration in the range from 20 ms to 1 s, preferably approximately 100 ms. The controller 16 b controls the demodulator 12 by means of a tuning signal in order to cause the demodulator 12 to receive and demodulate a specific program signal from a plurality of offered, receivable program signals by means of the tuning devices contained in the demodulator 12 . The controller 16 d ensures that the offered program signals are demodulated and compared in a certain order, and that the respective comparison results including the program identification information are stored in the memory 16 b.

The processing means 16 receives via the interface 3 b configuration data which are stored in the memory 16 b and specify which are to be included the program signals from the controller in the detection of the program usage behavior of the test subject with offered. The detection results from the memory 16 b via the interface 3 further read b.

The detection device 1 is supplied with electrical energy by a current source 17 .

The detection device according to the invention is accommodated as a miniaturized circuit in a housing which is suitable for being worn on the body of the test person. According to a preferred embodiment, the detection device 1 is accommodated as an integrated circuit in the housing of a wristwatch.

It is particularly advantageous to provide a sensor 18 which detects whether the detection device is actually being worn. For this purpose, a temperature sensor is provided in this exemplary embodiment. This detects the temperature of the rear cover of the housing and sends a signal to the processing device 16 which, depending on whether the detected temperature is above or below a temperature threshold, for example approximately 27 ° C., indicates whether the detection device is worn by the test person or was filed. The processing device 16 into consideration when storing the comparison result in the memory 16 b, whether the sensor signal from the sensor 18 indicating the wearing of the detecting device 1 by the test person. If this is not the case, the comparison result will not be registered or marked as unreliable.

C provided time from the clock function 16 is indicated in this embodiment by means of a suitable display device, such as a liquid crystal display on the top of the housing visible, so that the detecting device 1 satisfies the useful for the subject function of a wristwatch, which the willingness of the subject to Participation in the survey increases and thus the survey reliability increases.

Fig. 3 shows a second embodiment of the present invention. In this exemplary embodiment, elements which correspond to elements of the first exemplary embodiment have the same reference symbols and are not described again. In order to enable program signals (hereinafter referred to as bound program signals) that are not propagated in the form of free terrestrial high-frequency signals to be included in the detection of the program usage behavior, a stationary converter device 4 is provided according to this exemplary embodiment, which has bound program signals, for example via cables or optical fibers, receives them at an input, processes them and sends out a local program signal. This spreads spatially restricted where the test person usually consumes programs that are received in a manner that is bound to transmission media. In order to receive such programs, a conventional radio receiver 2 has, for example, in addition to or alternatively to the connection to the antenna 6, an input 6 a for cable program signals.

The detection device 1 according to the second exemplary embodiment has a sensor device 42 which serves to receive the local program signal. Unlike radio program signals, such as those emitted by a radio transmitter 9 , the spread of the local program signal is limited to a smaller spatial area, for example the test person's apartment.

The local program signal, which is emitted by the stationary converter device by means of a suitable transmitter device 41 , can be an infrared signal, an ultrasound signal or a freely propagating high-frequency signal. This signal carries one or more useful signals in accordance with programs that are offered for use via the propagation medium, for example cables. The local program signal is received by the detection device 1 by means of the sensor 42 and fed to the modulator devices, which demodulate the local program signal and recover the useful signal. This useful signal is then compared with a reference signal obtained acoustically via the microphone 7 of the detection device 1 . As in the first exemplary embodiment, the comparison results and further information such as the time and program identifier are stored.

The useful signal transmitted from the stationary converter device to the mobile detection device 1 by means of the local program signal is composed of a main signal which is generated from the demodulated bound program signal and an identification signal which identifies the main signal with the program signal just received via cable. The main signal can be the analog demodulated program signal, a digital demodulated program signal or an analog or digital signal which only bears characteristics of the demodulated program signal, which, as described below, are suitable as a basis for the comparison between the useful and reference signals.

The local program signal received by the sensor 42 in the detection device 1 is demodulated in order to recover the main signal and identification signal. The identification signal is separated from the main signal and stored in the detection device 1 together with the result of the comparison of the main signal and the reference signal.

The main signal is according to this embodiment in the receive stationary converter device in that the bound program signal demodulated and the thus obtained Signal is bandpass filtered, with cutoff frequencies accordingly that for comparison in the mobile detection device spectral range used, for example 300 Hz to 3 kHz. Then the bandpass filtered signal is in Converted digital signal.

The identification signal can be, for example, the RDS signal (Broadcast data system) or a digital one obtained from it Data signal, or the digitally encoded carrier frequency of the currently via cable from the stationary converter device received program signal.

As shown in FIG. 4, according to this exemplary embodiment, the identification signal I and then the main signal H for each currently received bound program signal a, b, c, d are successively modulated onto a local carrier. Each program signal included in the acquisition is given a cyclically recurring time slot in a predetermined time relationship with the other time slots occupied by other program signals. The main signal contains real-time digital data in each time slot corresponding to an uninterrupted period of the useful signal (for example 100 ms), which is dimensioned according to how much time is required to carry out a comparison of the useful signal and the reference signal. The local carrier thus modulated gives the local program signal.

FIG. 5 shows a block diagram of an exemplary embodiment of a stationary converter device according to the present invention. This converter device comprises a demodulator 46 , which has a cable input and a cable output for a radio device to be connected to it. The demodulator 46 generates the main signal from a received bound program signal by means of an analog / digital converter 48 in the manner described above.

The stationary converter device further comprises an encoder / decoder 47 for generating the identification signal. The main and identification signals are combined by a modulator 45 in the manner described above to form a useful signal and modulated onto a local carrier so as to form the local program signal. In this embodiment, the local carrier is a sequence of infrared light pulses with a frequency according to the bit rate to be transmitted, with data and synchronization signals being transmitted by varying the pulse width.

A control device 48 controls the operating sequence of the stationary converter device. Before the start of the acquisition period, it receives configuration data via a configuration interface 4 a, which determine which program signals or frequencies are to be included in the acquisition, and stores them. According to this data, it controls the sequence and the time sequence in which the demodulator is to demodulate the relevant program signals and the corresponding main signals or the encoder / decoder is to generate the assigned identification signals.

Fig. 6 shows a detection apparatus according to the second embodiment of the invention, which bound usage gathering program signals is provided by means of the above-described stationary transducer means. As far as the assemblies for receiving and processing the acoustic signal are concerned, the detection device according to the second exemplary embodiment corresponds to the first exemplary embodiment, as has been described with reference to FIG. 2.

Instead of the devices for receiving a radio program (antenna 5 , demodulator 11 , decoder 12 ), the detection device according to the second exemplary embodiment comprises a sensor 42 for receiving the infrared signal sent by the stationary converter device and a demodulator 43 which recovers the useful signal from the received infrared signal . A decoder 44 separates the useful signal into the main and identification signals. Since these signals are already in digitized form, this exemplary embodiment does not require an analog / digital converter in the branch which receives and processes the program signal, but only the A / D converter 14 in the signal path of the microphone signal.

Fig. 7 shows a detection apparatus according to a third embodiment of the present invention. This detection device is designed to include both program signals that are freely spreading and bound program signals in the detection of usage behavior. For this purpose, it includes devices for receiving a radio program signal as in the first embodiment and also a sensor 42 , demodulator 43 and decoder 44 , which perform the functions of the corresponding elements in the second embodiment. In addition, this exemplary embodiment comprises a first double changeover switch SW1, which is switched by the control device in such a way that the program signals received by means of the antenna 5 and by means of the sensor 42 are subjected to the comparison with the reference signal in a sequence predetermined by the control device. Incidentally, the function of the controller 16 d and the rest of elements 16 corresponds to the signal processing means to the first embodiment.

Fig. 8 shows a fourth embodiment of the detecting device according to the present invention. This embodiment includes all elements of the third embodiment. It advantageously takes advantage of the fact that the elements of the stationary converter device and the detection device largely correspond to one another in terms of their structure.

In addition to the third embodiment, the detection device of the fourth embodiment comprises a cable input connection 5 a, a modulator 45 and an infrared transmitter 41 . The modulator is connected to the signal processing device 16 via a changeover switch SW3. A switch SW2 enables switching of the input of the demodulator 12 either to a connection for a cable 5 a or to the antenna 5 in the device 1 . The changeover switches SW1 and SW3 are controlled by the signal processing device 16 .

The signal processing device 16 can be configured via the configuration interface 3 b in such a way that the device of the fourth exemplary embodiment is operated either as a detection device according to the first to third exemplary embodiments or as a stationary transmitter device. In FIG. 8, the position of the switch is marked SW1 to SW3 in the event that the device is configured as a stationary transducer device 1.

The stationary transducer device is advantageously designed so that it can be used in a holder, which via contacts, for example contact pins, with mating contacts, preferably contact surfaces in the surface, preferably in the back of the device, provides for the power supply of the device and the connection of a Broadband cable enables. For this purpose, the holder has a power supply unit and the necessary plugs or sockets, for example 75 ohms coaxial, as well as adaptation devices which enable the signal received via cable to be introduced into the device 1 via the contacts and counter-contacts.

The transmitting device 41 for transmitting the local program signal is preferably arranged embedded on the front of the device 1 in the surface. The holder can be designed such that when a device 1 equipped with a clock display on the front is inserted into it, the holder and device 1 result in a shelf clock designed as a decorative element. This increases the willingness of the test person to tolerate the installation of such a stationary converter device. Because the display device and transmitter device 41 are arranged on the front, the test person himself ensures the orientation of the stationary converter device in such a way that a radiation of the local program signal into the room is ensured.

This embodiment of the stationary converter device as a control clock is not limited to the case that the converter device is formed from a holder and a configurable device 1 according to the fourth exemplary embodiment. Rather, this configuration can also advantageously be used for the stationary converter device that was described in connection with FIG. 5.

In a modification of the third or fourth exemplary embodiment, a comparison of a reference signal obtained via microphone 7 with a useful signal, which is obtained by demodulating the bound program signal, is already carried out in the stationary converter device and only the result of the comparison to that of the stationary converter device mobile detection device carried by the test person. In this case, the local program signal that carries the result is broadcast locally by the stationary converter device as far as the sound signal that is broadcast by the radio device that the test person uses to use bound program signals. Accordingly, the mobile detection device also registers the use of a bound program signal in this exemplary embodiment only if the test person actually perceives the sound signal of the corresponding program. If the test person is outside the area within which the sound signal can be perceived, the mobile detection device does not receive the local program signal emitted by the stationary converter device and thus does not register the use of the relevant program signal.

This modification of the previous embodiments is advantageous in that the data transmission capacity of the local program signal to the mobile detection device lower requirements can be made because only the result of that in the stationary converter device made comparison to the mobile detection device must be transferred. However, this advantage is bought with a somewhat poorer detection reliability because the comparison is no longer based on the sound signal on Place of the test person, but only that Result is registered at the place of the test person.

Instead of or in addition to the transmission of the result of the comparison to the mobile detection device carried by the test person, the local program signal can carry a useful signal which corresponds to the program which was recognized in the stationary converter device as being in agreement with the reference signal. The useful signal transmitted with the local program signal is then compared again at the location of the test person in the detection device carried by the test person with a reference signal which is obtained by means of the microphone of the detection device. The result of the comparison carried out by the detection device is then stored. This embodiment can be obtained by appropriately configuring the device described with reference to FIG. 8.

This modification is advantageous in that the Data transmission capacity of the local program signal mobile detection device made less demands can be, since only a useful signal only transmit a program to the mobile detection device must become. There is also another comparison at the location of the  Test person in the detection device carried by this instead, so that a reliable detection result is obtained can be.

An exemplary embodiment of a detection strategy controlled by the control device 16 d in a detection device according to the invention is described below with reference to FIG. 9.

To record the usage behavior of the test person, the program signals to be included in the recording are examined for use by the test person at regular intervals (hereinafter referred to as the cycle), which are selected according to the desired temporal resolution of the detection result. For this purpose, the mobile detection device and, if appropriate, the stationary transducer device, relating to one or more of the parameters frequency range within which free or bound program signals are to be included in the detection, are started before the use is detected; Minimum reception field strengths to which the demodulator 12 for the free program signal or the demodulator 43 for the bound program signal should respond; Lists of program signals to be included in the acquisition, with associated frequency; Acquisition period from activation; Cycle; configured. The detection cycle can be selected depending on the time of day, for example a larger cycle at bedtime, and / or depending on whether the test person actually wears the detection device if a sensor 18 is provided in this regard.

In the flowchart of FIG. 9, n denotes a free program signal which is to be examined for current use by the test person. In order to save energy for the operation of the detection device, the control device 16 d switches the modules of the detection device into a state of reduced activity between two detection cycles, for example by reducing the system control clock.

To the wearable designed on the body of a test person It is special to miniaturize the detection device advantageous if this over the desired acquisition period from, for example, one to several weeks, within which the test person should carry the detection device with them, has a low energy requirement. On the energy needs of the mobile Detection device measures the size of the Power supply required power source, which at the Miniaturization is a limiting factor.

During an acquisition cycle, the acquisition strategy is therefore designed in such a way that as few of the program signals included in the acquisition have to be examined for use as possible. This is achieved in that if the use of a program signal has been detected in one detection cycle, the next detection cycle begins with the program signal previously detected as used. Alternatively or additionally, the number of comparisons is reduced by detecting at the beginning of each acquisition cycle whether there is a signal from the microphone 7 . If this is not the case, there is silence in the surroundings of the test person, and there is no need for further usage in this cycle.

In the exemplary embodiment shown in FIG. 9, the control device jumps from S2 via S10 to S8 in this case and waits there in the energy-saving mode until the start of the next cycle. If the total acquisition time has not yet elapsed (S9), the next cycle begins again with S2. If the microphone detects a signal above a predetermined threshold (S2), the associated program frequency is determined (S3) according to index n, the demodulator 11 is tuned to this frequency (S4), and then the comparison of the reference signal with the useful signal obtained from the demodulator is carried out (S6). If there is a match, one or more of the parameters time, program identifier, content identifier, date, validity is stored in the non-volatile memory 16 b of the detection device.

If there is no match, a check is made in S11 whether all program signals or whose frequencies were recorded in this cycle. If so, will in S8 in energy saving mode at the beginning of the next cycle waited and the program index n reinitialized. If not, the next program signal is indicated in S13 and then waited in S8.

If in a detection cycle after m (number of in the Acquisition of included program signals) runs of Loop S2-S6, S11, S13 determined that none of the in the acquisition of included program signals is used in S12 the program index n for the next acquisition cycle reinitialized. A reinitialization at the end of one Collection cycle does not take place when using it a program signal was detected. The next The acquisition cycle then begins with the one previously used detected program signal so that the continued use a program signal by the test person after the first Recording only a single comparison is required and the detection device then directly in the energy-saving wait state (S8) passes.

In S10 it is avoided that short pauses in the recorded as used Program to reinitialize the program index to lead. Only if, for example, over three acquisition cycles no microphone signal has been detected, the Program index n reinitialized.

After the acquisition period has expired, the mobile acquisition device deactivates itself (S9). The stored detection data are retained in the non-volatile memory 16 b.

Fig. 10 shows a second embodiment of the recording strategy according to the present invention. In order to further reduce the number of comparisons carried out by the detection device 1 , use is advantageously made, alternatively or in addition to the measures described in the previous exemplary embodiment, that people show preferences when using radio programs, ie use a specific radio program more often than others. For this purpose, according to the second embodiment, a table in the memory 16 b of the control device 16 is provided d, which contains a mapping of each of the m in the detection included program signals to priority P = 1 ... m. This table specifies the assigned program signal n (P) for each priority P. According to this exemplary embodiment, a detection cycle is started with the highest priority program signal, ie P = 1, when a microphone signal is present and it has previously been determined that none of the program signals involved in the detection has been used. The content of table n (P) is updated every time a new use of a program signal is determined, according to the frequency of the total use of the respective program signals recorded so far. Before the start of the acquisition period, it is only necessary to ensure by configuration of the table that an arbitrary program signal n is assigned to each priority value P. At the end of the acquisition period, the table contains a "hit list" of the program signals included in the acquisition according to the test subject's preferences. In addition to its usefulness for saving comparison processes, such a list is also of great demoscopic interest.

According to the exemplary embodiment shown in FIG. 10, each acquisition cycle begins with step S21, in which it is checked whether a microphone signal is present. This step corresponds to step S2 of the previous exemplary embodiment. If so, the assigned program signal n is read from the table in S22 according to the current priority P and the demodulator 12 is set to the corresponding frequency in S23. In S24, the reference signal is compared with the useful signal. This step corresponds to step S5 of the previous exemplary embodiment. If a match is found in S25, a hit flag is set to "yes" in S26. The hit marking serves to indicate in the following cycle whether a match was found in its previous cycle. S26 is followed by step S27 of storing the positive comparison result, which is described in more detail below. This is followed by steps S28 and S29, which correspond to steps S8 and S9 of the previous exemplary embodiment.

It is determined in S25 that there is no match between the useful signal and the reference signal is present in S32 checked in the previous cycle whether one of the uses in the detection of the program signals involved was determined. If this is the case, the test person has the program changed or switched off. Therefore S36 hits on set "no" and P in S37 to 1 to start with Highest priority program after a used program signal to search (loop S33, S38, S21 to S25, S32) until in S33 it is found that everyone involved in the registration Program signals were examined, or in S25 one Agreement has been established. In the former case P is set to 1 for the next cycle (S34), to use this to start the highest priority program. In the latter case the hit is set to "yes" (S26). Then in both cases a storage routine is carried out (S35 or S27) and then in S28 in energy saving mode for the next cycle waited.

In S25 there was a match between the useful and reference signals determined, and then waited in S28, the begins next comparison cycle with the last one used detected program signal, if not in the meantime a predetermined number of acquisition cycles (e.g. 3) due to lack a microphone signal from S21 to S28 abbreviated to S30 would. If e.g. B. three consecutive cycles via S30 pass, P is set to 1 to the next Detection process for which a microphone signal again  exists to start with the highest priority program signal, and hit set to "no" (S31).

Fig. 11 shows an embodiment of the storage routine, which is executed in steps S27 and S35. In order to save memory space in the signal processing device 16 , according to this exemplary embodiment, the recorded usage data are only stored in the event of a positive comparison result, and only if there has been a change from one recording cycle to the next. To do this, this routine uses the current hit marker and the state of the hit marker at the end of the previous cycle. Depending on the states of "hits" and "hits in the previous cycle", this routine performs the following actions:

Table 1

In S43 the switch-off time of the previously used as recorded program signal stored. In S45 the Priority table according to the number of times the respective programs were switched on updated in the previous data entry period and then P so updated to point to the same program signal index as before the update of the priority table. S45 will always active when a program or Switch to another program, i. H. another one Use of a program signal is detected. On this capture the program signals are updated according to their respective current  Frequency of use sorted into the priority table. If there is a change of location for the currently used detected program signal in the priority table, so accordingly in S45 corresponding to the change of location also P updated so that the updated P in the updated Table on the program signal shows which P before its Update in the table before updating it showed.

In S46, data relating to a are again used detected program signal, such as program identifier, Content identifier, etc. as described above, saved as well the switch-on time. In S47, a Program change in addition to the data as stored in S46 also the switch-off time of the abandoned program saved.

Only the case was described above that only free program signals are included in the detection via the antenna 5 of the detection device 1 . Alternatively, if a stationary converter device is provided, the program signals involved in the detection can be a local program signal from the stationary converter device corresponding to a bound program signal.

If, as a further alternative, both bound and free program signals are to be included in the detection, the detection device 1 reads in this case for every n from a table stored in it whether n denotes a local or a free program signal and accordingly guides the signal processing devices 16 a the corresponding useful signal received by the demodulator 11 for the free program signal or the useful signal received by the demodulator 43 for the local program signal.

If the local program signal transmits useful signals in accordance with the respective bound program signals in time slots as described above, the local detection device can calculate in advance from the predetermined temporal relationship between the transmissions of the individual useful signals when the useful signal is transmitted in accordance with the bound program signal indicated by n. Accordingly, it is sufficient for the mobile detection device to receive the local program signal until an identification data block of the useful signal has informed the control device 16 d which useful signal is to be transmitted next. On the basis of this information, the control device can then calculate the time at which the useful signal indicated by n occurs and switch to an energy-saving mode until it occurs.

In the following embodiments as it is performed by the signal processing means 16 a in the signal processing device 16 will be described in the comparison operation of the reference signal with the useful signal.

The tunable decoder 12 dwells on program signals from a predetermined reception strength with a predetermined dwell time. The dwell time can be specified on the production side or by configuration. The comparison between the reference signal and the useful signal takes place during this time. The dwell time on each program signal is dimensioned in such a way that maximum time differences between the reference signal and the useful signal and the time required for the comparison are taken into account. The actual comparison takes place using a method that delivers a result that is independent of runtime differences.

According to a first exemplary embodiment of a comparison method according to the invention, the comparison of reference signal and useful signal is carried out in the frequency domain. For this purpose, the digitized signals are transformed into the frequency range in the signal processing device 16 by means of a discrete Fourier transformation.

Depending on the location of the test person wearing the detection device 1 , there may be variable transit time differences in the range between 0 and 30 ms. These transit time differences result from the sound propagation speed over a distance between 0 and 10 meters.

Using an FFT (Fast Fourier Transformation), the two real signals, namely reference signal and useful signal, transform at the same time. However, there are others Transformation methods and algorithms can be used. Because of the maximum transit time difference of about 30 ms between the Both signals should be the sampling time for one Comparison process is approx. 90 ms. Will the two Signals each sampled with a sampling period of 100 µs, This results in a sampling time of around at 1024 sampling points 100 ms.

In order to rule out the influence of runtime differences on the comparison of the two signals, the amounts of the received frequency spectra of the reference signal and the useful signal are compared with one another according to this exemplary embodiment. In a first step, both magnitude spectra are first normalized, for example to the same mean. In the following, R _i and N _i denote the i-th components of the magnitude spectrum of the reference signal and the useful signal, respectively. In a subsequent step, an overall error F is calculated for each component i in accordance with the following rule:

If the total error F obtained is less than k times the mean of the Magnitude spectrum of the reference signal, so a positive Comparison result output, which is a match between the reference signal and the useful signal.

According to a second exemplary embodiment of a comparison method according to the present invention, striking spectral components R _i or N _i in the magnitude spectrum of the reference signal or the useful signal are determined, for example the 10 largest and 10 smallest magnitude components. Then the i-th components of the magnitude spectrum of N _i or R _{i are} compared with the corresponding striking magnitude components. As of a predetermined number x of matches, the two magnitude spectra are considered identical, and a positive comparison result is output. Agreement here means that the amount of the difference between R _i and N _{i is} smaller than a further predetermined value.

According to a third embodiment of an inventive The magnitude spectra R and N are compared using Fuzzy logic compared. The following are steps carried out:

Step 1 Comparison of the individual amounts

IF | R _i

- N _i

| = SMALL
THEN T _i

= TRUE
T _i

Partial match; can be TRUE or FALSE take in

If the difference of | R _i - N _i | is small, the partial match T _{i is} TRUE.

The "Membership Function" from KLEIN corresponds, for example a Gaussian function.

Since in this exemplary embodiment the number of partial amounts is fixed to 512 according to 1024 sampling points in the time domain, the number of non-matches is also fixed. According to a modification of this exemplary embodiment, instead of this rough subdivision, an examination can also be extended to an average MEDIUM match. Defuzzification is not carried out in this exemplary embodiment. The correspondence between the reference signal and the useful signal is determined according to the rule

IF number of partial matches = LARGE
THEN overall match = TRUE
certainly.

The membership function for LARGE can look as shown in Fig. 12.

step 2

Comparison of whether positive or negative changes (direction) from R _i to R _{i + 1 can} also be found in N (f).

IF (R _{i + 1} - R _i ) = KN AND (N _{i + 1} - N _i ) = KN
OR (R _{i + 1} - R _i ) = KP AND (N _{i + 1} - N _i ) = KP
THEN RA _{i, i + 1} TRUE

KN: SMALL NEGATIVE
KP: SMALL POSITIVE
RA: change of direction

If the difference between R _{i + 1} - R _i is SMALL NEGATIVE and the difference between N _{i + 1} - N _{i is} also SMALL NEGATIVE, or if the difference between R _i-1 - R _i is SMALL POSITIVE and the difference from N _{i + 1} - N _{i is} also SMALL POSITIVE, the change of direction from _i to _{i + 1 is the} same in both magnitude spectra and thus true.

step 3

The results of step 1 and step 2 each result a vector of 512 boolean values. In this third Step is now preferably examined whether Mismatches or unequal changes of direction as "Burst" are present. Burst denotes an accumulation of Mismatches in a section of the  Frequency spectrum. In the simplest case, "Burst" takes the two boolean values TRUE or FALSE. "Burst" is TRUE if more than x (e.g. 30) successive values of the two Magnitude spectra do not match or differ Show changes in direction. There can be several for "burst" "Membership Functions" (LOW, MEDIUM, HIGH) defined to refine the classification and reliability to increase the comparison result.

Step 4

The following rule can now be drawn up for the evaluation:

IF number of partial matches = LARGE
AND number of same direction changes = LARGE
AND burst = FALSE
OR number of partial matches = medium
AND number of same direction changes = means
AND burst = TRUE
OR ....... (further, finer divisions)
THEN overall match = TRUE

One could also for the degree of overall agreement Introduce SMALL, MEDIUM, LARGE membership functions to in a later evaluation the credibility of the statement to check. Again, there is no de-fuzzification, but rather the so-called alpha value is used.

This results in the following sequence of steps to achieve the comparison result:

• 1. Receive useful signal and reference signal
• 2. Acquisition of 1024 samples for reference and Useful signal.
• 3. Transformation of the samples according to R (f) or N (f).  
• 4. Forming the mean values | R (f) | and | N (f)
  • 1. 4.1 If the mean of the magnitude spectrum of the useful signal is outside a specified range, jump to point 2.
  • 2. 4.2 After x (e.g. 3) invalid queries according to point 4.1 change the gain factor of the useful signal accordingly and jump to point 2.
  • 3. 4.3 After y (eg 3) invalid attempts jump to point 1 according to point 4.2.
• 5. Comparison of the individual amounts of the standardized amount spectra | R '(f) | and | N '(f) |.
  • 1. 5.1 Call up the knowledge base according to step 1.
  • 2. 5.2 Call up the knowledge base according to step 2.
  • 3. 5.3 As a result of points 5.1 and 5.2, two vectors are obtained, each with 512 boolean values. These vectors are now to be examined individually for so-called "bursts".
  • 4. 5.4 Call up the knowledge base according to step 4.
    If match = TRUE, jump to point 6 Otherwise match = FALSE, jump to point 1.
• 6. Output a comparison result

According to a modification of this exemplary embodiment, the amplification factor of the microphone amplifier 13 can also be changed analogously to steps 4.1 to 4.3 until the mean value of the magnitude spectrum of the reference signal lies within a predetermined range.

The implementation of such standardization is not based on that last described embodiment limited, but can in all embodiments of a comparison method be applied.

In the following a further embodiment of a Method according to the invention for detecting a match between reference signal and useful signal described in the Time range is performed. In a first step Differential signal and useful signal normalized, for example regarding their mean. For the actual comparison the digitized useful signal is used as a reference signal used. The digitized reference signal is now Sample by sample compared with the useful signal, and the error, for example, for every 8 samples Total errors added up.

This process is repeated several times to make a possible existing transit time difference between the two signals eliminate. Before each comparison, the sequence of the Samples in each case by one sampling period T compared to the Shift sequence of the samples of the useful signal. At A maximum of 30 ms runtime difference results in up to 300 Comparisons. To reduce the high number of comparisons, is preferred according to this embodiment parallelized circuit structure (hardware) used to to make eight comparisons in parallel, for example. As an alternative or in addition to this measure you can by Averaging, for example, three consecutive Values the number of comparisons can be further reduced.

From the comparisons carried out, the comparison becomes Assessment of conformity, which the smallest comparison error results. This is the smallest A comparison error below a specified threshold will result in a  Agreement of the reference signal with the useful signal spent.

Accordingly, the following procedure follows:

• 1. Receive useful signal and reference signal.
• 2. Acquisition of 1024 samples for each reference signal and useful signal
• 3. Formation of the mean values of the reference signal and the useful signal
  • 1. 3.1 If the mean value of the useful signal is outside a specified range, jump to point 2.
  • 2. 3.2 If x (eg 3) invalid queries according to point 3.1, change the gain factor of the useful signal accordingly and jump to point 2.
  • 3. 3.3 jump to point 1 after y (e.g. 3) invalid attempts according to point 3.2.
• 4. Comparison of the standardized signals sample by sample
  • 1. 4.1 If 1024 values are assumed, only the first 724 values for the formation of comparison error V1 are to be compared with one another.
  • 2. 4.2 Shift sequence of the sample values of the reference signal to the left by ΔT, compare the first 724 values again and form comparison error V2.
  • 3. 4.3 Repeat 4.2 until the specified transit time difference (here 30 ms) is zero.
  • 4. 4.4 Find the smallest comparison error Vx.
  • 5. 4.5 If Vx ≦ match threshold, then
    Match = TRUE
    Otherwise agreement = FALSE.

Claims (28)

1. Device for detecting the use of radio programs, with

• 1. a microphone ( 7 , 13 ) for receiving audible acoustic signals and outputting a reference signal corresponding to the acoustic signal;
• 2. a receiver ( 43 ) with a sensor ( 42 ) for receiving and demodulating a local program signal in the form of high-frequency signals, infrared signals or ultrasound signals, which is emitted by a stationary converter device ( 4 ) which receives program signals distributed via antenna or cable and in converts the local program signal and for outputting a useful signal; and
• 3. Devices ( 16 a) for comparing the reference signal supplied by the microphone ( 7 , 13 ) with the useful signal supplied by the receiver ( 12 ) and outputting a respective comparison result;
• 4. wherein the device ( 1 ) is designed to be portable on the body of a person.

2. Device for detecting the use of radio programs, with

• 1. a microphone ( 7 , 13 ) for receiving audible acoustic signals and outputting a reference signal corresponding to the acoustic signal;
• 2. a receiver ( 12 ) for receiving and demodulating program signals and outputting a useful signal;
• 3. Devices ( 16 a) for comparing the reference signal supplied by the microphone ( 7 , 13 ) with the useful signal supplied by the receiver and outputting a respective comparison result;

marked by

• 1. Devices ( 41 , 45 ) for transmitting a local program signal carrying the comparison result to a mobile comparison result detection device which can be carried by a test person.

3. Device according to claim 1 or 2, characterized in that

• 1. the local program signal carries a useful signal including program identification information.

4. Device according to one of the preceding claims, characterized in that - The receiver ( 12 , 43 ) has tuning devices and is designed to sequentially demodulate different program signals. 5. Device according to one of the preceding claims, characterized by

• 1. decoder devices ( 11 , 44 ) for decoding program and / or station identification signals contained in the program signals.

6. Device according to one of the preceding claims, characterized by

• 1. storage devices ( 16 b) for storing the comparison results for the respective useful signals compared with the reference signal;
• 2. wherein the storage devices ( 16 b) are designed to store information relating to time intervals in which the comparison result output is positive and / or station identifiers in this regard.

7. The device according to claim 6, characterized in that the memory devices ( 16 b) comprise non-volatile memory. 8. Device according to one of claims 6 and 7, characterized in that the comparison devices ( 16 a) comprise:

• 1. Means ( 14 , 15 ) for converting the useful signal and the reference signal into digital signals; and
• 2. digital signal processing devices ( 16 a) which can receive the digital signals and process them to produce the comparison result.

9. The device according to claim 8, characterized by a microprocessor ( 16 d) for controlling the detection process. 10. The device according to claim 9, characterized by

• 1. an interface device ( 3 b) for configuring the device and / or for reading out the memory content.

11. Method for recording the use of radio programs with the steps:

• 1. Receiving a program signal offered for use via antenna or cable and converting the program signal into a local program signal which is emitted in the form of high-frequency, infrared or ultrasonic signals;
• 2. receiving audible audible signals and outputting a reference signal corresponding to the acoustic signal;
• 3. receiving the local program signal and demodulating the local program signal into a useful signal; and
• 4. Comparison of the reference signal with the useful signal supplied by the demodulation devices and output of a respective comparison result.

12. The method according to claim 11, characterized by the steps

• 1. sampling and converting the reference signal and the useful signal into a first and a second digital signal;
• 2. transforming the first and second digital signals into the frequency domain and forming a first and second digital frequency spectrum, respectively; and
• 3. Compare the first frequency spectrum with the second frequency spectrum.

13. The method according to claim 12, characterized by

• 1. forming the sum of difference amounts or squares of differences between corresponding frequency components; and
• 2. Output a positive comparison result if the sum is less than a threshold value.

14. The method according to claim 12 or 13, characterized in that

• 1. the threshold value is a function of the mean values of the amounts of the first and / or second frequency spectrum.

15. The method according to claim 12, characterized by the steps

• 1. Detecting the frequency position of at least one local minimum and / or maximum in the first and / or in the second frequency spectrum;
• 2. Comparing the frequency positions of the extremes detected in the spectrum of the useful signal with the frequency positions of the extremes detected in the spectrum of the first signal; and
• 3. Output of a positive comparison result if a predetermined number of frequency positions less than or equal to the number of detected frequency positions essentially match.

16. The method according to claim 15, characterized in that

• 1. The frequency positions of a predetermined number of the largest local maxima of the spectrum of the useful signal and the spectrum of the first signal are compared with one another.

17. The method according to claim 16, characterized by the steps:

• 1. Detection of the frequency positions of a number of local extremes in the first or in the second spectrum;
• 2. comparing the first or second spectrum with the second or first spectrum at the detected frequency position; and
• 3. Output of a positive comparison result if the first and second spectra correspond to one another in a predetermined proportion of the number of extreme frequencies.

18. The method according to claim 12, characterized by the steps

• 1. forming difference amounts between spectral component amounts of the same frequency of the first and second digital signals;
• 2. determining a number of difference amounts, which are small according to a first fuzzy membership function; and
• 3. Output a positive comparison result if the number of small difference amounts according to a second fuzzy membership function is large.

19. The method according to claim 18, characterized by

• 1. Determine a number of successive difference amounts which are not small according to the first fuzzy membership function; and
• 2. Output of the positive comparison result if this number is not large according to a third fuzzy membership function.

20. The method according to claim 18 or 19, characterized by

• 1. Detecting first differences between adjacent spectral components of the first digital signal and determining second differences between adjacent spectral components of the second digital signal;
• 2. Detecting a number of spectral components for which the first and second differences are the same according to a fourth fuzzy membership function; and
• 3. Output the positive comparison result if the number of spectral components for which the first and second differences are small is large according to a fifth fuzzy membership function.

21. The method according to claim 20, characterized by

• 1. Detecting a number of successive spectral components for which the first and second differences according to the fourth fuzzy membership function are not the same; and
• 2. Output of the positive comparison result if this number is not large according to a sixth fuzzy membership function.

22. The method according to claim 11, characterized by the steps:

• 1. sampling and converting the reference signal and the useful signal into a first and a second digital signal;
• 2. transforming the first and second digital signals into the frequency domain and forming a first and second digital frequency spectrum, respectively;
• 3. multiplying the first signal spectrum by the complex conjugated second frequency spectrum or by the second frequency spectrum to obtain a third spectrum;
• 4. Transform the third spectrum back into the time domain to obtain a third signal;
• 5. detection of the maximum value of the third signal; and
• 6. Output a positive comparison result if the detected maximum value exceeds a threshold value.

23. The method according to claim 22, characterized in that

• 1. the threshold value is determined as a function of the amplitudes of the reference signal and / or of the useful signal.

24. The device according to one of claims 1 to 10, characterized in that the comparison devices ( 7 , 13 ) are designed such that

• 1. in a detection cycle (S3-S8, S11-S13) it is detected (S6) whether a program signal is used;
• 2. a recorded program signal usage is stored (S7)
• 3. wait until the next acquisition cycle in a state of reduced energy consumption (S8);
• 4. In the event that the use of a program signal has been detected in a detection cycle, the following detection cycle begins with the program signal previously detected as used.

25. The device according to claim 24, characterized by the steps:

• 1. At the beginning of a detection cycle, detecting (S2) whether there is a reference signal with a level above a predetermined threshold; and
• 2. If the level of the reference signal is below the predetermined threshold, end the detection cycle and wait in the state of reduced energy consumption until the next detection cycle (S9).

26. The device according to claim 24 or 25, characterized by the steps:

• 1. detecting the usage frequency (S45) for each program signal included in the usage detection; and
• 2. if no use of a program signal has been detected in the previous detection cycle (S21, S33), the following detection cycle begins with the program signal (S30, S34), which so far has had the greatest usability.

27. Method for recording the use of radio programs, with the steps:

• 1. receiving a program signal offered by antenna or cable for use and converting the program signal into a useful signal;
• 2. receiving audible audible signals and outputting a reference signal corresponding to the acoustic signal;
• 3. comparing the reference signal with the useful signal supplied by the demodulation devices and outputting a respective comparison result; and
• 4. Sending a local program signal carrying the comparison result to a comparison result detection device which can be carried by a test person.