Apparatus and method for automatically monitoring broadcast band listening habits

Claim 3

The method of claim 1 wherein step (b) further comprises tuning said tuner only to broadcast band frequencies then being broadcast in an area in which listening habits are being monitored.

Claim 4

The method of claim 1 wherein steps (a) and (b) are continuously performed.

Claim 5

The method of claim 1 wherein steps (a) and (b) are intermittently performed.

Claim 6

The method of claim 1 wherein steps (a) and (b) are periodically performed.

Claim 7

The method of claim 1 wherein steps (a) and (b) are continuously performed until a match is found and thereafter periodically performed until the match is lost.

Claim 8

The method of claim 1 wherein step (b) is performed only when the signal sensed in step (a) exceeds a threshold level.

Claim 9

The method of claim 1 wherein step (c) further comprises recording the broadcast frequency at which the match is found.

Claim 10

The method of claim 8 wherein step (c) further comprises recording the date upon which a match is found.

Claim 11

The method of claim 8 further comprising updating and recording a running check-sum of the logged data.

Claim 12

The method of claim 1 wherein steps (a) and (b) are intermittently performed at a first rate until a match is found and thereafter intermittently performed at a second rate until the match is lost.

Claim 13

The method of claim 11 wherein the first and second rates are equal.

Claim 14

The method of claim 11 wherein the first rate has a higher frequency than the second rate.

Claim 15

The method of claim 12 wherein step (b) further comprises first tuning successively to a set of stored frequencies at which a match was previously found and thereafter tuning to other frequencies until a match is found.

Claim 16

The method of claim 14 further comprising updating the set of stored frequencies at which a match was previously found with a frequency at which a match is found.

Claim 17

The method of claim 1 further comprising an additional step: (d) recording the time a match is lost.

Claim 18

The method of claim 16 wherein the recording of step (d) occurs only after a match is lost for more than a predetermined time.

Claim 19

The method of claim 16 wherein step (c) further comprises recording a frequency at which a match is found.

Claim 20

The method of claim 18 further comprising an additional step: (e) transmitting the times and broadcast frequencies recorded in the monitor to a central collecting station.

Claim 21

The method of claim 19 wherein step (e) further comprises transmitting the dates recorded in the monitor to the central collecting station.

Claim 22

The method of claim 18 further comprising an additional step: (f) erasing the times and frequencies recorded in the monitor.

Claim 23

The method of claim 1 further comprising electronically sensing an internal power supply level and discontinuing steps (a) through (c) when the power supply level sensed falls below a predetermined value.

Claim 24

The method of claim 22 wherein the electronic monitor retains times and frequencies recorded when the power supply level falls below the predetermined value.

Claim 25

The method of claim 23 further comprising recording the occurrence of the internal power supply falling below the predetermined level.

Claim 26

The method of claim 24 further comprising recording the occurrence of the internal power supply rising above the predetermined level.

Claim 27

The method of claim 25 further comprising checking the set of stored frequencies and the running check-sum and an internal time-of-day clock for valid values.

Claim 28

The method of claim 26 further comprising establishing communication with a central station and restoring a correct set of stored frequencies and valid value for the internal time-of-day clock in the event that an invalid value is discovered by the checking.

Claim 29

The method of claim 27 wherein the communication with the central station is established daily.

Claim 30

Apparatus for automatically monitoring broadcast band listening habits comprising: (a) a portable self-powered electronic monitor, said monitor comprising: (i) sensor means for sensing energy in the audio frequency spectrum and providing an output representative thereof, (ii) first signal conversion means connected to said sensor means output for providing a first electronic signal representative thereof; (iii) electronic tuner means for receiving a selectable broadcast band signal free of an injected identification signal and for providing a second electronic signal representative thereof; (iv) autocorrelation means for autocorrelating said first and second eletronic signals and for providing first and second sets of correlation coefficients respectively indicative thereof; and (v) control means connected to said tuner means for controlling the tuning of said tuner means by changing the tuning of said tuner means and comparison means for comparing said first with said second set of correlation coefficients until a match is found between said first and second electronic signals, and recording as data a time at which said match is found.

Claim 31

Apparatus for automatically monitoring broadcast band listening habits comprising: (a) a portable self-powered electronic monitor, said monitor comprising: (i) sensor means for sensing energy in the audio frequency spectrum and providing an output representative thereof, (ii) first signal conversion means connected to said sensor means output for providing a first electronic signal representative thereof; (iii) electronic tuner means for receiving a selectable broadcast band signal free of an injected identification signal and for providing a second electronic signal representative thereof; (iv) autocorrelation means for autocorrelating said first and second eletronic signals and for providing first and second sets of correlation coefficients respectively indicative thereof; and (v) control means connected to said tuner means for controlling the tuning of said tuner means by changing the tuning of said tuner means and comparison means for comparing said first with said second set of correlation coefficients until a match is found between said first and second electronic signals, and recording as data a time at which said match is found.

Claim 32

The apparatus of claim 29 wherein said control means further comprises means for further recording as data a broadcast frequency at which said match is found.

Claim 33

The apparatus of claim 29 wherein said control means further comprises a real-time clock.

Claim 34

The apparatus of claim 29 wherein said sensor means comprises an input jack means for receiving a line input of broadcast band program material from an earphone jack output of a broadcast band receiver.

Claim 35

The apparatus of claim 29 wherein said sensor means comprises a microphone circuit having an audio-frequency-sensitive microphone.

Claim 36

The apparatus of claim 33 wherein said microphone circuit further comprises an automatic level control circuit means for compressing the dynamic range of the output of said microphone circuit.

Claim 37

The apparatus of claim 29 wherein the first signal conversion means further comprises a digitizer means for converting said first electronic signal into a digital format.

Claim 38

The apparatus of claim 35 wherein said digitizer means further comprises means for converting said second electronic signal into a digital format.

Claim 39

The apparatus of claim 29 wherein said monitor further comprises: (v) digital signal processing means receiving said first and second electronic signals for comparing said first and second electronic signals to determine whether a match is present between said first and second electronic signals.

Claim 40

The apparatus of claim 37 wherein said digital signal processing means calculates at least one correlation coefficient corresponding to the degree of correlation between said first and second electronic signals.

Claim 41

The apparatus of claim 38 wherein said digital signal processing means periodically computes said correlation coefficient.

Claim 42

The apparatus of claim 38 wherein said digital signal processing means calculates a plurality of correlation coefficients.

Claim 43

The apparatus of claim 29 wherein said control means is responsive to said first electronic signal to hold the monitor in a low power consumption state while said first electronic signal is below a threshold level.

Claim 44

The apparatus of claim 41 wherein said control means is further responsive to said second electronic signal to hold the monitor in a low power consumption state while said second electronic signal is below a threshold level.

Claim 45

The apparatus of claim 29 further comprising: (b) a base unit for said electronic monitor, said base unit comprising (i) means for physically receiving said monitor on said base unit, and (ii) means for communicating information to and from said monitor through said base unit when said monitor is received on said base unit.

Claim 46

The apparatus of claim 43 wherein said means for communicating information further comprises a telephone interface for transmitting said recorded data to a central data collection station via a telephone connection.

Claim 47

The apparatus of claim 43 wherein said monitor further comprises a rechargeable battery and said base unit further comprises: (iii) electrical power connection means for recharging said battery.

Claim 50

The method of claim 46 wherein step (a) is performed by a microphone circuit.

Claim 51

The method of claim 46 wherein step (a) is performed by an audio amplifier circuit directly receiving the audio signal at a headphone jack.

Claim 52

The method of claim 46 wherein said electronic monitor is portable and has an internal rechargeable power supply.

Claim 53

The method of claim 49 further comprising periodically coupling the portable monitor to a base unit for recharging the internal power supply of the portable monitor.

Claim 54

The method of claim 50 further comprising communicating the recorded data to a central data collection station through the base unit when the portable monitor is coupled to the base unit.

Claim 55

The method of claim 46 wherein step (c) further comprises digitizing the audio signals of steps (a) and (b) and comparing the digitized signals.

Claim 56

The method of claim 52 wherein the digitized signals are concurrently compared.

Claim 57

The method of claim 52 wherein the signals are alternately digitized and compared.

Claim 58

The method of claim 52 wherein the digitized signals are compared by electronically computing correlation coefficients.

Claim 59

The method of claim 46 wherein step (c) comprises comparing spectrograms formed as a result of steps (a) and (b).

Claim 60

The method of claim 46 wherein step (c) comprises comparing templates formed as a result of steps (a) and (b).

Claim 61

The method of claim 46 wherein steps (a) and (b) each further comprise auto correlating each signal before comparing them in step (c).