EP1032998A1

EP1032998A1 - Voice recognition unit for audience measurement system

Info

Publication number: EP1032998A1
Application number: EP98926519A
Authority: EP
Inventors: Daozheng Lu; David H. Harkness; Gordon R. Price
Original assignee: Nielsen Media Research LLC
Current assignee: TNC US Holdings Inc
Priority date: 1997-11-20
Filing date: 1998-06-09
Publication date: 2000-09-06
Also published as: CA2306095A1; CN1282470A; JP2001524776A; AU7833898A; WO1999027668A1

Abstract

A member of an audience of a program to which a receiver is tuned is identified by a system which includes first and second microphones, a noise cancellation unit, and a voice recognition unit. One of the first and second microphones picks up relatively more of a voice signal from the member of the audience, and the other of the first and second microphones picks up relatively more of a sound signal from the receiver. The noise cancellation unit substantially eliminates the sound signal from the voice signal. The voice recognition unit identifies the member from the member's voice signal. The first and second microphones, the noise cancellation unit, and the voice recognition unit may be housed in a hand held housing or in a table top housing. The system may also include a passive people meter to passively identify the member, and a program to identify the program or channel to which the receiver is tuned.

Description

VOICE RECOGNITION UNIT FOR AUDIENCE MEASUREMENT SYSTEM

Technical Field of the Invention

The present invention relates generally to an

audience measurement system that identifies members of an

audience of a program to which a receiver, such as a

television, radio, or computer, is tuned, and/or that

identifies a program to which a receiver, such as a

television, radio, or computer, is tuned.

Background of the Invention

Measuring audiences of programs has long been

of interest to program suppliers and advertisers because

audience measurements provide the data from which the

effectiveness of programs and advertisements may be eval-

uated. A variety of well known methods have been em¬

ployed in order to provide an estimate of the total audi¬

ence to a program, to a portion of a program, and/or to a

commercial. In addition to the total audience, these

methods provide additional estimates of demographically

significant audience segments (e.g., the number of men

and/or women between certain ages who watched a selected portion of a given program) . These methods involve manu¬

ally and/or automatically measuring the viewing and/or

listening habits of audience members of statistically

selected households and then estimating the total audi-

ence based on these measurements . Audience members of

statistically selected households are usually referred to

as panelists.

The measurement of the viewing and/or listening

habits of an audience generally requires three separate

determinations: (1) a determination of the channels or

stations to which the monitored receivers are tuned with¬

in the statistically selected households; (2) a determi¬

nation of the programs which were available on the tuned

channels at the times during which the receivers were

tuned to these channels or stations; and, (3) a determi¬

nation of the household members and visitors who were

present in the area of the receivers during the time that

the receivers were tuned to selected programs.

All three determinations can affect the accu-

racy of audience measurements. Of the three determina¬

tions discussed above, determination (3) perhaps most affects the accuracy of audience measurements because the

members of an audience of a receiver are usually required

to cooperate in the identification process. When members

are required to participate in the identification pro-

cess, they frequently make errors, or they simply forget

to identify either themselves or the other members of the

audience. For example, one known system which allows

audience members to identify themselves in order to indi¬

cate their presence is a "People Meter." The "People

Meter" may be a remote control and/or a plurality of push

buttons activated by the audience members when they enter

or exit the monitored area. However, audience members

frequently forget to press any button at all, or they

sometimes make errors in pressing the right button.

In an attempt to overcome this problem, several

measurement systems have been developed. For example, in

U.S. Patent No. 3,056,135, Currey et al . describe a sys¬

tem which utilizes strategically placed switches for

counting the number of persons entering, leaving, and re-

maining within a monitored area, and a photographic re¬

corder for periodically recording the composition of the audience. This approach requires that the photographic

record be viewed by an operator, which both invades the

privacy of the audience members, and imposes an unaccept¬

able cost on the measurement operation.

These problems led to a variety of suggestions

for passive, non-obtrusive methods of counting (but not

identifying) viewers, and of tracking their movement

about the monitored area. For example, Kiewit, et al . ,

in U.S. Patent No. 4,644,509, describe an ultrasonic

sonar system which counts and tracks members of the audi¬

ence. However, the described system does not identify

the members of the audience and, therefore, requires the

members of the audience to manually identify themselves.

Other systems, such as that described by Kiewit

in U.S. Patent 4,930,011, rely upon electronically active

tags which are worn or carried by members of an audience

and which uniquely identify corresponding ones of these

audience members . These systems respond to the tags

whenever the audience members wearing the tags are within

the monitored area of a receiver. However, audience members often forget to wear their tags, in which case

such audience members are not identified.

Lu, in U.S. Patent No. 4,858,000, and in U.S.

Patent No. 5,031,228, discloses an image recognition

system for identifying the members of an audience of a

receiver. The system uses a video camera to acquire

images of the faces of the audience members, and a com¬

puter subsystem to recognize the faces in these images by

comparing these faces to reference faces stored in a data

base. The system also locates and tracks viewers, and

includes infrared illuminators that provide a control¬

lable level of imperceptible illumination of the moni¬

tored area for the video camera. However, the system is

generally expensive and difficult to install.

The system disclosed by Lu et al . , in U.S.

Patent No. 5,550,928 also uses image recognition to iden¬

tify audience members. This system incorporates algo¬

rithms for finding bodies and then heads of members of an

audience. Once the head is found, a face finding algo-

rithm extracts facial image representations that are

provided to two face recognition routines, an Eigenface recognition routine and a template matching routine.

This system can identify audience members who are moving

about the monitored area and/or who are not facing the

cameras. However, it is still complex and expensive.

Determinations (1) and (2) discussed above also

can affect the accuracy of audience measurements because

one of these determinations alone is normally not suffi¬

cient to identify the programs to which receivers are

tuned. That is, a determination of the channels to which

a receiver in a statistically selected household is tuned

does not lead to a determination of the tuned programs

without also knowing what programs were available on the

tuned channels. By the same token, a determination of

the programs that were available on the tuned channels

does not lead to a determination of the tuned programs

without knowing the channels to which the receiver in a

statistically selected household is tuned. Thus, both

determinations are typically required in order to deter¬

mine the programs tuned by the audience members .

Acquisition of information about available programs and

entering this information into a database for later matching with the tuned channels leads to acquisition and

data entry errors that adversely affect the accuracy of

audience measurements.

Thomas et al . , in U.S. Patent No. 5,481,294,

addresses these problems with an audience measurement

system that detects and records ancillary codes which are

embedded in, and identify, the programs to which receiv¬

ers are tuned. Thus, only one determination needs to be

made if an ancillary code is present in the viewed pro-

grams. If ancillary codes are not available in the tuned

programs, program signatures are extracted from the pro¬

grams and are compared to reference signatures previously

extracted.

The metering apparatus disclosed in this patent

may include non-intrusive sensors, such as microphones

near the receiver, that detect the ancillary codes in the

audio output of the monitored receivers. If microphones

are used to detect the ancillary codes, second micro¬

phones may be provided to pick up background noise. The

outputs of the ancillary code sensing microphones and the

noise sensing microphones are processed in order to sub- tract the background noise from the signals provided by

the ancillary code sensing microphones.

This audience measurement system may also in¬

clude a "People Meter" as described above for additional

backup .

Turner et al . , in U.S. Patent No. 4,907,079,

disclose a system for monitoring audiences of receivers.

The members of the audience provide control commands

(such as channel selections) to a microprocessor through

an infrared unit which includes a keyboard. Information

collected by the microprocessor may be stored and trans¬

mitted to a central computer over conventional phone

lines. A motion detector coupled to the microprocessor

detects when an audience member has entered or exited the

monitored area. A character generator coupled to the

microprocessor allows communication with the audience

members via alphanumeric messages displayed, for example,

on a television screen. Also, a speech output unit cou¬

pled to the microprocessor generates speech signals to

communicate to the audience members. The Turner et al . system also includes a speech

input unit coupled to the microprocessor to allow audi¬

ence members to audibly identify themselves. Audible

speech from the audience members is detectable by a mi-

crophone, is amplified, is digitized, and is provided to

the microprocessor. The microprocessor performs a power

density spectrum analysis on the signal to derive voice

signatures of the particular audience members. These

signatures are compared to reference signatures, which

were previously stored during initialization of the sys¬

tem, in order to identify viewers. The microprocessor

may also normalize the digital voice data and remove

small amplitude samples in order to minimize the effects

of background noise. When the system disclosed in this

Turner et al . patent is activated, an initial display

message is placed on the viewing screen which requests

the audience to speak their first and last names in order

to provide the reference signatures. Voice recognition

by itself does not, however, permit a viable audience

measurement system. Moreover, the disclosed signal pro- cessing that minimizes the effects of background noise

may not be adequate under many conditions.

The present invention is directed to a system

which identifies members of an audience of a receiver and

which solves one or more of the problems noted above .

Summary of the Invention

In accordance with a first aspect of the pres¬

ent invention, a system for identifying a member of an

audience of a receiver comprises first and second micro-

phones, a noise cancellation unit, and a voice recogni¬

tion unit . The first and second microphones are arranged

so that one of the first and second microphones picks up

relatively more of a voice signal from the member of the

audience and the other of the first and second micro-

phones picks up relatively more of a sound signal from

the receiver. The noise cancellation unit is coupled to

the first and second microphones, and the noise cancella¬

tion unit is arranged to substantially eliminate the

sound signal from the voice signal. The voice recogni-

tion unit is coupled to the noise cancellation unit, and the voice recognition unit is arranged to identify the

voice signal from the member of the audience.

In accordance with another aspect of the pres¬

ent invention, a system comprises a microphone, a voice

recognition unit, and a program sensor. The system iden¬

tifies a member of an audience of a program to which a

receiver is tuned. The microphone is located to receive

a voice signal from the member. The voice recognition

unit is coupled to the microphone and is arranged to

identify the member from the voice signal. The program

sensor is arranged to identify the program.

In accordance with yet another aspect of the

present invention, a system comprises a passive people

meter, a microphone, a voice recognition unit, and a con-

troller. The system identifies a member of an audience

of a program to which a receiver is tuned. The passive

people meter is arranged to provide a first identifica¬

tion of the member by passively identifying the member.

The microphone is located to receive a voice signal from

the member. The voice recognition unit is coupled to the

microphone and is arranged to provide a second identifi- cation of the member by identifying the member from the

voice signal. The controller is arranged to select at

least one of the first and second identifications in

order to identify the member.

In accordance with still another aspect of the

present invention, an audience recognition unit comprises

a housing, a microphone supported by the housing, and a

voice recognition unit supported by the housing and cou¬

pled to the microphone. The voice recognition unit is

arranged to recognize a member of an audience from an

identifier spoken by the member. Accordingly, the audi¬

ence recognition unit identifies the member of the audi¬

ence of a program to which a receiver is tuned.

Brief Description of the Drawings

These and other features and advantages of the

present invention will become more apparent from a de¬

tailed consideration of the invention when taken in con-

junction with the drawings in which:

Figure 1 illustrates the system of the present

invention for use in identifying members of an audience

of a program to which a television receiver is tuned;

Figure 2 is a block diagram of an embodiment of

the system which is in accordance with the present inven¬

tion and which includes an audience recognition unit

(ARU) ;

Figure 3 is a more detailed diagram of the

audience recognition unit shown in Figure 2 ;

Figure 4 is a diagram of a noise cancellation

arrangement for use in the audience recognition unit

shown in Figure 2 ;

Figure 5 illustrates a hand held version of the

audience recognition unit shown in Figure 3 ;

Figure 6 illustrates a table top version of the

audience recognition unit shown in Figure 3; Figure 7 is a flow chart depicting a program

which may be implemented by the audience recognition unit

shown in Figure 3 during a training period; and,

Figure 8 is a flow chart depicting a program

which may be implemented by the audience recognition unit

shown in Figure 3 during voice recognition of audience

members .

Detailed Description

An audience measurement system 10, which deter-

mines the members of an audience to a program to which a

monitored receiver is tuned, is shown in Figure 1. The

audience measurement system 10 includes an audience

recognition unit 12, which is shown in Figure 1 as a hand

held unit but which alternatively may be any other type

of unit, such as a table top unit. The audience recog¬

nition unit 12 permits the members of the audience to be

identified either passively or actively, and may or may

not interact with a receiver 14 during the identification

process . A program sensor 16 cooperates with the re¬

ceiver 14 in order to determine the programs (and/or

channels) to which the receiver 14 is tuned. The program

sensor 16 may be any known sensor which determines chan-

nels (and/or programs) . For example, the program sensor

16 may sense ancillary codes which are embedded in the

program signals to which the receiver 14 is tuned and

which specifically identify the tuned programs. In addi¬

tion, or alternatively, the program sensor 16 may include

a signature extractor which extracts characterizing sig¬

natures from the program signals to which the receiver 14

is tuned so that the signatures may be compared to refer¬

ence signatures in order to identify the programs (and/or

channels) to which the receiver 14 is tuned. In addi-

tion, or alternatively, the program sensor 16 may be an

apparatus which determines the channels to which the

receiver 14 is tuned by monitoring the tuner of the re¬

ceiver 14.

The audience measurement unit 12 and the pro-

gram sensor 16 communicate with a base unit 18 which may

be either a site unit or a home unit . As is known in the art, a site unit may be provided at each audience area

within a household, and all site units within the house¬

hold may communicate to a home unit over the electrical

power lines in the walls of the household. The home unit

may then communicate by way of the public telephone sys¬

tem with a central unit which gathers tuning and audience

information from other households so that the information

can be combined into reports useful to program suppliers,

advertisers, and the like. In households having only one

viewing area, the base unit 18 may be arranged to both

receive data from the audience measurement unit 12 and

the program sensor 16, and may communicate this data by

way of the public telephone system to the central unit .

Thus, as shown in Figure 2, the audience

recognition unit 12 provides its recognition data to the

base unit 18 by way of a communication link 20 which, for

example, may be an infrared or RF communication link.

The program sensor 16 provides its program identification

data to the base unit 18 by way of a communication link

21 which, for example, may be a hard wire, but which may

alternatively be any other communication link, such as an infrared or RF communication link. The base unit 18

collects the audience recognition data from the audience

recognition unit 12 and the program identification data

from the program sensor 16, and may communicate this data

over a public telephone system 22 to a central site 24

which accumulates similar data from other households.

As indicated in Figure 2, the audience measure¬

ment system 10 may also include a passive people meter

26. For example, the passive people meter 26 may be of

the type which passively identifies audience members in a

monitored area in accordance with the teachings of U.S.

Patent No. 5,550,928 described above. The passive people

meter 26 provides its people identification data to the

base unit 18 by way of a communication link 28 which, for

example, may be a hard wire, but which may alternatively

be any other communication link, such as an infrared or

RF communication link.

Accordingly, if the audience measurement system

10 includes both the audience recognition unit 12 and the

passive people meter 26, the passive people meter 26 may

be used to passively identify audience members in the event that the audience recognition unit 12 is unable to

do so. Alternatively, the audience recognition unit 12

may be used to actively or passively identify audience

members in the event that the passive people meter 26 is

unable to passively identify audience members. As a

still further alternative, the outputs of both the audi¬

ence recognition unit 12 and the passive people meter 26

may be applied simultaneously to a soft decision logic

that identifies audience members based upon both of these

outputs. In any of these alternatives, confidence is in¬

creased that audience members can be accurately recog¬

nized.

The audience recognition unit 12 is shown in

more detail in Figure 3. The audience recognition unit

12 includes first and second microphones 30 and 32. The

first and second microphones 30 and 32 are positioned in

the audience recognition unit 12 so that one of the first

and second microphones 30 and 32 tends to pick up rela¬

tively more of the voice signals from the audience mem-

bers, and the other of the first and second microphones

30 and 32 tends to pick up relatively more of the audio output from the monitored receiver. For example, the

first and second microphones 30 and 32 may be separated

so that, in most orientations of the audience recognition

unit 12, one of the first and second microphones 30 and

32 is closer to the audience members and the other of the

first and second microphones 30 and 32 is closer to the

monitored receiver. A preferred separation between the

first and second microphones 30 and 32 is 6.72 inches,

although any other suitable separation may be used. In

this embodiment of the present invention, the first and

second microphones 30 and 32 may be pointed in opposite

directions. Alternatively, one or both of the first and

second microphones 30 and 32 may be located remotely from

the audience recognition unit 12 so that one of the first

and second microphones 30 and 32 is closer to the audi¬

ence members and the other of the first and second micro¬

phones 30 and 32 is closer to the monitored receiver.

The analog output of the first microphone 30 is

amplified by an amplifier 34, and this amplified analog

output is converted to a digital signal by an analog to

digital converter 36. Similarly, the analog output of the second microphone 32 is amplified by an amplifier 38,

and this amplified analog output is converted to a digi¬

tal signal by an analog to digital converter 40.

Even though the first and second microphones 30

and 32 can be positioned or directed so that one of the

first and second microphones 30 and 32 tends to pick up

relatively more of the voice signals from the audience

members and the other of the first and second microphones

30 and 32 tends to pick up relatively more of the audio

output from the monitored receiver, the first and second

microphones 30 and 32 pick up both the voice signals from

the audience members and the audio output from the re¬

ceiver 14. Also, both the first and second microphones

30 and 32 pick up background noise other than the audio

output from the receiver 14. In order to reduce or elim¬

inate the effects of background noise and the audio out¬

put from the receiver 14, the outputs from the analog to

digital converters 36 and 40 are provided to a noise

cancellation arrangement 42. The noise cancellation

arrangement 42 processes the outputs from the analog to

digital converters 36 and 40 so as to cancel the audio output of the receiver 14 as well as background noise

from the voice signals provided by the audience members,

so that these voice signals may be more easily identi¬

fied.

The noise cancellation arrangement 42 may use

signal subtraction in order to subtract background noise

and the audio output of the receiver 14 from the voice

signals provided by the audience members. For example,

if the first microphone 30 is directed toward the audi-

ence members, and if the second microphone 32 is directed

toward the receiver 14, the signal from the first micro¬

phone 30 may be designated S_p (p meaning people) , and the

signal from the second microphone 32 may be designated as

S_r (r meaning reference) . In general, the signal S_p may

be given according to the following equation:

S_P = aV„ bV. (1)

where S_p is the signal from the first microphone 30, V_p is

the contribution to the signal from the first microphone

30 due to the voice signals of the members of the audi- ence, V_r is the contribution to the signal from the first

microphone 30 due to the audio output of the receiver 14

and other background noise, a and b are parameters dis¬

cussed below, and a is greater than b.

Similarly, the signal S_r may be given according

to the following equation:

S_r = cV_p + dV_r (2)

where S_r is the signal from the second microphone 32, c

and d are parameters discussed below, and c is less than

d. Equations (1) and (2) may be subtracted with a

weighting parameter e according to the following equa¬

tion:

D = eS ( ae c) -V + (be - d) -V p o:

where D is the weighted difference between equations (1)

and (2) , and e is a weighting parameter discussed below.

If a, b, c, and d are fixed parameters deter¬

mined by the environment and the features of the first and second microphones 30 and 32, the weighting parameter

e can be selected so that (be - d) = 0, or so that e =

d/b > 1. Accordingly, if (be - d) = 0, the difference D

will consist only of the signal V_p. In this case, the

signal V_p from equation (3) is given by the following

equation :

D

V (4i ae - c

Because a, e, and c are constants in a given household,

these constants may be treated as a single constant k ac-

cording to the following equation:

= (5) ae - c

so that the signal V_p is given by following equation:

V_n = kD. !6)

The weighting parameter e may be determined

adaptively during periods when the receiver 14 is on but

no member of the audience is talking. During such a

period, the audience recognition unit 12 can automati¬

cally find the weighting parameter e so that D = 0. This

weighting parameter e is then inserted into equations (5)

and (6) in order to determine V_p, and V_p is processed by a

voice recognition unit 44 as discussed below.

This noise cancellation approach assumes that

the first microphone 30 is directed to, or is closer to,

the audience than is the second microphone 32, and that

the second microphone 32 is directed to, or is closer to,

the receiver 14 than is the first microphone 30. For

example, if the audience recognition unit 12 is a hand

held unit, the first microphone 30 and the second micro¬

phone 32 may be mounted on the audience recognition unit

12 so that they are separated and so that the user is directed to orient the audience recognition unit 12 with

the first microphone 30 directed toward the audience and

the second microphone 32 directed toward the receiver 14.

Similarly, if the audience recognition unit 12 is a table

top unit, the first microphone 30 and the second micro¬

phone 32 again may be mounted on the audience recognition

unit 12 so that they are separated and so that the user

is directed to orient the audience recognition unit 12

with the first microphone 30 directed toward the audience

and the second microphone 32 directed toward the receiver

14. Alternatively, whether the audience recognition unit

12 is a hand held unit or a table top unit, the first and

second microphones 30 and 32 may be connected to the

audience recognition unit 12 by lines or other communica-

tion media which permit the first microphone 30 to be

mounted in close proximity to the audience and the second

microphone 32 to be mounted in close proximity to the

receiver 14.

Instead of canceling noise as discussed above,

the noise cancellation arrangement 42 may use phase

cancellation. It is noted that sound travels at approxi- mately 1,120 ft per second in air. Sounds not originat¬

ing equidistant from both of the first and second micro¬

phones 30 and 32, which are preferably separated by 6.72

inches, reach these microphones at different times and

are canceled or are at least partially canceled. Based

on the actual frequencies of the sounds, and the spacing

between the first and second microphones 30 and 32, dif¬

ferent phase angles result . The noise cancellation ar¬

rangement 42 implementing phase cancellation uses these

different phase angles in order to cancel the audio out¬

put from the receiver 14 and other background noise from

voice signals provided by the members of the audience.

In this embodiment of the present invention, the first

and second microphones 30 and 32 are preferably direc-

tional microphones mounted on the same side of the audi¬

ence recognition unit 12. The audience recognition unit

12 may have any orientation with respect to the audience

and the receiver 14 as long as the first and second mi¬

crophones 30 and 32 and not pointed directly at the re-

ceiver 14. In this embodiment of the present invention,

the noise cancellation arrangement 42 may be of the form

shown in Figure 4. According to this embodiment, the

noise cancellation arrangement 42 includes an amplifier

60, which amplifies the signal from the first microphone

30, and an amplifier 62, which amplifies the signal from

the second microphone 32. Because the amplifiers 60 and

62 may be essentially the same, only one of the amplifi¬

ers is shown in detail in Figure 4. The outputs of the

amplifiers 60 and 62 are summed by a summer 64 so that

background noise is substantially eliminated. The output

from the summer 64 is detected and converted to a DC

level by a detector 66 and is supplied to a timer 68.

If the output of the summer 64 is above a

predetermined threshold, the timer 68 is triggered and

provides an output to a switch 70 in order to connect the

output of the summer 64 to the voice recognition unit 44.

The voice recognition unit 44 provides a hold signal

through a terminal 72 in order to hold the timer 68 in

its triggered state until a predetermined time after the

voice recognition unit 44 last recognizes a voice. The voice recognition unit 44 may be an RSC164

voice recognition processor provided by Sensory Inc. The

voice recognition unit 12 compares the output from the

noise cancellation arrangement 42 to prestored reference

voice signals (identifiers) stored in a memory. These

prestored reference voice signals (identifiers) may be

spoken identifier words or voice features from a speaker¬

's frequency spectrum. When matches are found, members

of the audience are identified, and the voice recognition

unit 44 provides a suitable identification record to a

controller 46 for each match. The controller 46 stores

the identification record in a memory 48 for later

transmission to the base unit 18 by way of a communica¬

tion arrangement 50. The communication arrangement 50

may use the communication link 20 as previously de¬

scribed. The controller 46 may also be coupled to a

clock 52 so that the times that the members of the audi¬

ence are identified may also be stored in the memory 48.

A prompt unit 54 may also be coupled to the

controller 46. The controller 46 controls the prompt

unit 54 in order to prompt audience members to either provide their corresponding voice signals to the first

and second microphones 30 and 32, or use a keypad 56 in

order to manually identify themselves. The prompt unit

54 may be a voice synthesizer and/or a graphic or video

display (such as an LCD or LED) of the audience recog¬

nition unit 12 arranged to provide audible and/or visible

prompts to the members of the audience. Alternatively,

the prompt unit 54 may be the speakers and/or the screen

of the receiver 14 arranged to provide audible and/or

visible prompts to the members of the audience in re¬

sponse to interaction with the audience recognition unit

12.

The audience recognition unit 12 may be

implemented as a hand held unit 90 which is illustrated

in Figure 5. The hand held unit 90 includes a housing 92

that houses the elements of the audience recognition unit

12 which are shown in Figure 3. The housing 92 supports

an LED display 94 which may perform the functions of the

prompt unit 54. As noted above, however, the prompt unit

54 alternatively may be a voice synthesizer, in which

case the housing 92 would incorporate an output speaker to project audible voice prompts from the voice synthe¬

sizer to the members of the audience. The LED display 94

(and/or the voice synthesizer) may perform functions

other than prompting. The housing 92 also houses an IR

transmitter 96 for establishing the communication link 20

shown in Figure 2. Alternatively, the communication link

20 may be established by an ultrasonic or RF link, a hard

wire, or the like. The housing 92 further supports a

keypad 98, which may be the keypad 56 shown in Figure 3,

for allowing audience members to enter data. For exam¬

ple, predetermined ones of the keys in the keypad 98 may

be assigned to members and visitors of the audience so

that they may identify themselves manually if they cannot

be recognized through their voice signals. The housing

92 may contain a rechargeable battery which is arranged

to provide power to the audience recognition unit 12 and

which may be charged overnight or when the audience rec¬

ognition unit 12 is not in use. The hand held unit 90

also has a power on/off button 95 in order to turn the

hand held unit 90 on and off, and an LED 97 in order to indicate that the hand held unit 90 is ready to identify

audience members and visitors.

Alternatively, the audience recognition unit 12

may be implemented as a table top unit 100 which is

illustrated in Figure 6. The table top unit 100 includes

a housing 102 that houses the elements of the audience

recognition unit 12 which are shown in Figure 3. The

housing 102 may support an LED display (not shown) in

order to implement the functions of the prompt unit 54.

As noted above, however, the prompt unit 54 alternatively

may be a voice synthesizer, in which case the housing 102

would incorporate an output speaker to project audible

voice prompts from the voice synthesizer to the members

of the audience. The LED display or the voice synthe-

sizer may perform functions other than prompting. The

housing 102 may also house an IR or RF transmitter (not

shown) for establishing the communication link 20 shown

in Figure 2. Alternatively, the communication link 20

may be established by an ultrasonic link, a hard wire, or

the like. The housing 102 supports a keypad 104, which

may be the keypad 56 shown in Figure 3, for allowing audience members to enter data. For example, predeter¬

mined ones of the keys in the keypad 104 may be assigned

to members of the audience so that they may identify

themselves manually if they cannot be recognized through

their voice signals. The table top unit 100 may contain

a rechargeable battery which is arranged to provide power

to the audience recognition unit 12 and which may be

charged overnight or when not in use. Alternatively, the

table top unit 100 may have a power cord for providing

power to the audience recognition unit 12 from an elec¬

trical outlet. Also, the table top unit 100 may have a

power on indicator light 106 and a voice detected indica¬

tor light 108.

During a training mode, the controller 46 of

the audience recognition unit 12 may implement a program

120 depicted in Figure 7 by way of a flow chart. The

program 120 is executed during the training mode in order

to store identifier words or voice features associated

with the members of the audience. During training, an

audience member should assume a position at a specified

distance from the audience recognition unit 12. This audience member initiates training by pressing an

appropriate key or button on the keypad 56 of the audi¬

ence recognition unit 12.

When the training mode is initiated so that the

program 120 is executed, the audience recognition unit

12, at a block 122, determines whether a predetermined

amount of time has passed since the last audience member

activity. If the audience recognition unit 12 determines

that there has been no audience member activity for the

predetermined amount of time, the program 120 assumes

that the training mode has ended and the program 120

exits. If the predetermined amount of time has not pass¬

ed since the last audience member activity, the audience

recognition unit 12, at a block 124, continues to wait

for a wakeup command to be spoken. The wakeup command

should be a unique word or word combination not normally

present in the audio of the receiver 14. The audience

member should speak the wakeup command in a normal voice

to the first and second microphones 30 and 32. When the

audience recognition unit 12 detects the wakeup command,

the audience recognition unit 12, at a block 126, prompts the audience member to say the identifier word which the

viewer has chosen to identify himself or herself. Such

an identifier word may be the name of the viewer.

The audience recognition unit 12 then deter-

mines at a block 128 whether the audience member has said

the identifier. If not, the audience recognition unit

12, at the block 126, again prompts the audience member

to say the identifier word. If the audience recognition

unit 12 determines at the block 128 that the audience

member has said the identifier word, the audience recog¬

nition unit 12, at a block 130, suitably processes the

identifier word and stores the identifier word in the

memory 48. Flow returns to the block 122 where the

training mode is terminated or another audience member

enters a corresponding identifier word.

During an identification mode, the controller

46 of the audience recognition unit 12 may implement a

program 140 depicted in Figure 8 by way of a flow chart.

The program 140 is executed during the identification

mode in order to identify members of the audience. The

identification mode may be initiated by pressing an appropriate key or button on the keypad 56 of the audi¬

ence recognition unit 12.

When the identification mode is initiated so

that the program 140 is executed, the audience recogni-

tion unit 12, at a block 142, determines whether an audi¬

ence member desires to end the identification mode by

pressing an appropriate key or button on the keypad 56 of

the audience recognition unit 12. If the audience recog¬

nition unit 12 determines that the audience member de-

sires to end the identification mode, the program 140

exits. If the audience recognition unit 12 determines

that the audience member does not desire to end the iden¬

tification mode, the audience recognition unit 12, at a

block 144, waits for a wakeup command to be spoken. The

audience member should speak the wakeup command in a

normal voice to the first and second microphones 30 and

32. When the audience recognition unit 12 detects the

wakeup command, the audience recognition unit 12, at a

block 146, prompts the audience member to say his or her

identifier word. The audience recognition unit 12 then deter¬

mines at a block 148 whether the audience member has said

the identifier word. If not, the audience recognition

unit 12, at the block 146, continues to prompt the audi-

ence member to say the identifier word. If the audience

recognition unit 12 determines at the block 148 that the

audience member has said the identifier word, the audi¬

ence recognition unit 12, at a block 150, instructs the

voice recognition unit 44 to compare the identifier word

to the vocabulary of identifier words stored in the mem¬

ory 48.

If the audience recognition unit 12 determines

at a block 152 that the voice recognition unit 44 detects

a match between the spoken identifier word and one of the

identifier words stored in the memory 48, the audience

recognition unit 12, at a block 154, stores the spoken

identifier word and the time of the match as an

identification record in the memory 48 for immediate or

later communication to the base unit 18. (Alternatively,

the audience recognition unit 12, at the block 154, may

communicate the spoken identifier word and time directly to the base unit 18.) If the audience recognition unit

12 determines at the block 152 that the voice recognition

unit 44 cannot match the spoken identifier word to one of

the identifier words stored in the memory 48, the audi-

ence recognition unit 12, at a block 156, prompts the

audience member to try again or to use another form of

identification. For example, the prompt 140 may prompt

the audience member to speak his or her identifier word a

predetermined number of times before prompting the audi-

ence member to use another form of identification (such

as entering the identifier word through use of the keypad

56) . Alternatively, or additionally, if the controller

46 determines that the voice recognition unit 44 cannot

detect a match at the block 152, the controller 46 at the

block 156 may send a message to the base unit 18 indi¬

cating that identification should be made from the pas¬

sive people meter 26. After the audience recognition

unit 12, at the block 154, stores the spoken identifier

word and the time of the match as an identification re-

cord in the memory 48, or after the audience recognition

unit 12, at the block 156, prompts the audience member to try again, or to use another form of identification, or

to send a suitable message to the base unit 18 to seek an

identification from the passive people meter 26, or the

like, flow returns to the block 142.

The advantage of using a wakeup command during

normal voice recognition is that the comparison process

is simplified. That is, during normal audience recogni¬

tion, each spoken identifier word is compared to every

reference identifier word stored in the memory 48. How-

ever, the wakeup command only needs to be compared to one

reference in the memory 48.

The block 126 of Figure 7 and the block 146 of

Figure 8 may be arranged to also prompt each audience

member to speak a cue in addition to the member's identi-

fier word. The advantage of coupling a cue to an identi¬

fier word is to minimize the possibility that the audi¬

ence recognition unit 12 may incorrectly identify a per¬

son as an audience member when that person's identifier

word is contained in the audio output of the receiver 14,

but that person is not in the audience. For example, the

identifier word may be a name, and the cue may be a word common to all audience members, such as the word "enter,"

or the word "exit," or the like. Thus, a member of the

audience, when entering (or leaving) the monitored area,

speaks his or her name, as the identifier word, coupled

with the cue. For example, the member may say "John

enter" or "Mary enter." Alternatively, the cue may be

unique to each audience member. Either arrangement

reduces the likelihood that a word audibly emitted by the

receiver 14 will be mistaken as an identifier word spoken

by a member of the audience.

Certain modifications of the present invention

have been discussed above. Other modifications will

occur to those practicing in the art of the present

invention. For example, the invention has been described

above in connection with measuring the audiences of tele¬

vision programs. However, the present invention is use¬

ful also in measuring the audiences of radio programs and

programs of other media.

Also, the program sensor 16 is described above

as sensing the program and/or channel to which the re¬

ceiver 14 is tuned. Instead, the audience recognition unit 12 may be arranged to accept manual entry of program

identifications by the audience members through use of

the keypad 56.

Moreover, the functions of a remote control may

be incorporated into the audience recognition unit 12.

Furthermore, instead of relying upon two micro¬

phones, such as the first and second microphones 30 and

32, the audience recognition unit 12 may rely upon a

single, close range directional microphone. If so, noise

cancellation may not be necessary.

In addition, the use of a wakeup command may be

eliminated.

Also, as described above, the passive people

meter 26 may be of the type which passively identifies

audience members in a monitored area in accordance with

the teachings of U.S. Patent No. 5,550,928 described

above. However, the passive people meter 26 may be any

known type of passive device that is capable of passively

identifying members of an audience. For example, the

passive people meter 26 may use an ultrasonic and/or

infrared transducer or an array of such transducers in order to capture an image of the audience area and may

use processing algorithms in order to recognize members

in the audience .

Moreover, the passive people meter 26, as des-

cribed above, passively identifies audience members in a

monitored area. If the passive people meter 26 cannot

passively identify the members in the audience, it can be

arranged to count the members of the audience and to

prompt manual identification of the members until the

number of manually identified members equals the count.

Alternatively, if the passive people meter 26 cannot

passively identify every member in the audience, it can

be arranged to count the members of the audience and to

prompt manual identification of those members which it

cannot passively identify. As a still further alterna¬

tive, a counter may be used instead of the passive people

meter 26. The counter can comprise an ultrasonic and/or

infrared transducer or an array of such transducers or

other device or devices which can detect people in the

audience and can count the number of detected people.

Then, the audience measurement system 10 could be ar- ranged to prompt manual identification until the number

of people manually identified equals the count.

Furthermore, the audience measurement unit 12,

the program sensor 16, and the passive people meter 26

are shown in Figure 2 as being separate elements. In¬

stead, the audience measurement unit 12 may include the

program sensor 16 and/or the passive people meter 26.

Accordingly, the description of the present

invention is to be construed as illustrative only and is

for the purpose of teaching those skilled in the art the

best mode of carrying out the invention. The details may

be varied substantially without departing from the spirit

of the invention, and the exclusive use of all modifica¬

tions which are within the scope of the appended claims

is reserved.

Claims

WHAT IS CLAIMED IS:

1. A system for identifying a member of an

audience of a receiver comprising:

first and second microphones arranged so that

one of the first and second microphones picks up rela-

tively more of a voice signal from the member of the

audience and the other of the first and second micro-

phones picks up relatively more of a sound signal from

the receiver;

a noise cancellation unit coupled to the first

and second microphones, wherein the noise cancellation

unit is arranged to substantially eliminate the sound

signal from the voice signal; and,

a voice recognition unit coupled to the noise

cancellation unit, wherein the voice recognition unit is

arranged to identify the voice signal from the member of

the audience .

2. The system of claim 1 further comprising a

program sensor arranged to identify a program received by

the receiver.

3. The system of claim 2 wherein the program

sensor comprises a channel sensor.

4. The system of claim 2 wherein the program

sensor comprises a code reader arranged to detect a pro-

gram identifying code in a program to which the receiver

is tuned.

5. The system of claim 2 wherein the program

sensor comprises a signature extractor arranged to ex-

tract uniquely identifiable signatures from a program to

which the receiver is tuned.

6. The system of claim 2 wherein the program

sensor comprises a keypad arranged to permit the member

of the audience to key in a program or channel identity.

7. The system of claim 1 further comprising a

clock and a memory, wherein the memory stores an identity

of the member of the audience based upon the voice signal

from the member, and wherein the memory stores a time

from the clock when the member is identified.

8. The system of claim 1 wherein the receiver

is a television.

9. The system of claim 1 wherein the receiver

is a radio.

10. The system of claim 1 wherein the receiver

is a multimedia reception device.

11. The system of claim 1 further comprising a

keypad arranged to accept an identification input from

the member of the audience .

12. The system of claim 1 further comprising a

prompting device arranged to prompt the member of the

audience to say the voice signal .

13. The system of claim 12 further comprising

a sensor to identify a program or channel received by the

receiver .

14. The system of claim 12 further comprising

a passive people meter arranged to passively identify the

member of the audience.

15. The system of claim 14 further comprising

a sensor to identify a program or channel received by the

receiver.

16. The system of claim 1 wherein the voice

signal comprises an identifier of the member of the audi┬¼

ence .

17. The system of claim 1 wherein the voice

signal comprises an identifier and a cue of the member of

the audience.

18. The system of claim 1 further comprising a

passive people meter arranged to passively identify the

member of the audience.

19. The system of claim 1 further comprising a

communication unit arranged to communicate the identity

of the member and/or program identity to a remote point .

20. The system of claim 19 wherein the

communication unit is arranged to communicate the iden-

tity of the member to the remote point by way of infrared

signals .

21. The system of claim 1 wherein the first

and second microphones, the noise cancellation unit, and the voice recognition unit are housed in a hand held

housing.

22. The system of claim 1 wherein the first

and second microphones, the noise cancellation unit, and

the voice recognition unit are housed in a table top

housing.

23. The system of claim 1 wherein the first

and second microphones are directionally oriented in

substantially opposite sensing directions.

24. The system of claim 1 wherein the first

microphone is mounted closer to the audience than is the

second microphone, and wherein the second microphone is

mounted closer to the receiver than is the first micro┬¼

phone .

25. The system of claim 1 further comprising a

counter, a display, and a manual entry device, wherein

the voice recognition unit is arranged to supply prompts to the display in order to prompt manual identification

of members of the audience through use of the manual

entry device until the members so identified equal a

count supplied by the counter.

26. A system for identifying a member of an

audience of a program to which a receiver is tuned, the

system comprising:

a microphone located to receive a voice signal

from the member;

a voice recognition unit coupled to the micro-

phone and arranged to identify the member from the voice

signal; and,

a sensor arranged to identify the program or

channel .

27. The system of claim 26 further comprising

a memory arranged to store reference identification

information corresponding to the member, and wherein the

voice recognition unit is arranged to identify the member based upon a comparison of the voice signal and the ref┬¼

erence identification information.

28. The system of claim 27 wherein the sensor

is arranged to identify the program based upon a feature

of the program.

29. The system of claim 28 wherein the feature

is an identification code embedded in the program.

30. The system of claim 28 wherein the feature

is an uniquely identifiable signature extracted from the

program.

31. The system of claim 26 wherein the re┬¼

ceiver is a television.

32. The system of claim 26 wherein the re┬¼

ceiver is a radio.

33. The system of claim 26 wherein the re┬¼

ceiver is a multimedia reception device.

34. The system of claim 26 further comprising

a keypad arranged to accept an identification input from

the member.

35. The system of claim 34 wherein the

identification input is an identification of the member.

36. The system of claim 34 wherein the

identification input is a program or channel identifica┬¼

tion.

37. The system of claim 26 further comprising

a prompting device arranged to prompt the member to say

the voice signal .

38. The system of claim 37 further comprising

a passive people meter arranged to passively identify the

member .

39. The system of claim 26 wherein the voice

signal comprises an identifier of the member.

40. The system of claim 26 wherein the voice

signal comprises an identifier and a cue for the member.

41. The system of claim 26 further comprising

a passive people meter arranged to passively identify the

member .

42. The system of claim 26 further comprising

a communication unit arranged to communicate the identity

of the member to a remote point .

43. The system of claim 42 wherein the

communication unit is arranged to communicate the iden-

tity of the member to the remote point by way of infrared

signals .

44. The system of claim 26 wherein the icro-

phone and the voice recognition unit are housed in a hand

held housing.

45. The system of claim 26 wherein the micro-

phone and the voice recognition unit are housed in a

table top housing.

46. The system of claim 26 further comprising

a counter, a display, and a manual entry device, wherein

the voice recognition unit is arranged to supply prompts

to the display in order to prompt manual identification

of members of the audience through use of the manual

entry device until the members so identified equal a

count supplied by the counter.

47. A system for identifying a member of an

audience of a program to which a receiver is tuned, the

system comprising:

a passive people meter arranged to provide a

first identification of the member by passively identify-

ing the member;

a microphone located to receive a voice signal

from the member;

a voice recognition unit coupled to the micro-

phone and arranged to provide a second identification of

the member by identifying the member from the voice sig-

nal; and,

a controller arranged to select at least one of

the first and second identifications in order to identify

the member.

48. The system of claim 47 wherein the con-

troller includes a prompting unit arranged to prompt the

member to say the voice signal.

49. The system of claim 48 further comprising

a sensor arranged to identify the program or channel.

50. The system of claim 47 wherein the con-

troller includes a prompting unit arranged to prompt the

member to say the voice signal if the passive people

meter is unable to provide the first identification.

51. The system of claim 47 wherein the con-

troller is arranged to select the first identification if

the voice recognition unit is unable to provide the sec┬¼

ond identification.

52. The system of claim 47 wherein the voice

signal comprises an identifier.

53. The system of claim 47 wherein the voice

signal comprises an identifier and a cue.

54. The system of claim 47 further comprising

a sensor arranged to identify the program or channel.

55. The system of claim 47 further comprising

a communication unit arranged to communicate the identity

of the member to a remote point .

56. The system of claim 55 wherein the

communication unit is arranged to communicate the iden-

tity of the member to the remote point by way of infrared

signals .

57. The system of claim 47 wherein the micro-

phone and the voice recognition unit are housed in a hand

held housing.

58. The system of claim 47 wherein the micro-

phone and the voice recognition unit are housed in a

table top housing.

59. The system of claim 47 further comprising

a counter, a display, and a manual entry device, wherein

the controller is arranged to supply prompts to the dis-

play in order to prompt manual identification of members of the audience through use of the manual entry device

until the members so identified equal a count supplied by

the counter.

60. An audience recognition unit that identi-

fies a member of an audience of a program to which a

receiver is tuned, the audience recognition unit compris-

ing :

a housing;

a microphone supported by the housing; and,

a voice recognition unit supported by the hous-

ing and coupled to the microphone, the voice recognition

unit being arranged to recognize the member from an iden┬¼

tifier spoken by the member.

61. The audience recognition unit of claim 60

further comprising a prompt unit supported by the hous-

ing, wherein the prompt unit is arranged to prompt the

member to take an action.

62. The audience recognition unit of claim 61

further comprising a keypad supported by the housing,

wherein the keypad is arranged to permit the member to

enter data.

63. The audience recognition unit of claim 62

further comprising a communication unit supported by the

housing, wherein the communication unit is arranged to

communicate data to a base unit .

64. The audience recognition unit of claim 63

further comprising a clock and a memory supported by the

housing, wherein the memory stores an identity of the

member based upon the spoken identifier, and wherein the

memory stores a time from the clock when the member is

identified.

65. The audience recognition unit of claim 64

wherein the identifier includes a word and a cue.

66. The audience recognition unit of claim 60

further comprising a keypad supported by the housing,

wherein the keypad is arranged to permit the member to

enter data.

67. The audience recognition unit of claim 66

further comprising a communication unit supported by the

housing, wherein the communication unit is arranged to

communicate data to a base unit .

68. The audience recognition unit of claim 60

further comprising a communication unit supported by the

housing, wherein the communication unit is arranged to

communicate data to a base unit .

69. The audience recognition unit of claim 60

further comprising a clock and a memory supported by the

housing, wherein the memory stores an identity of the

member based upon the spoken identifier, and wherein the

memory stores a time from the clock when the member is

identified.

70. The audience recognition unit of claim 60

wherein the identifier includes a word and a cue.

71. The audience recognition unit of claim 60

wherein the audience recognition unit is a hand held

unit .

72. The audience recognition unit of claim 60

wherein the audience recognition unit is a table top

unit .