GB2139389A - Identification apparatus - Google Patents

Abstract

An individual trying to obtain credit or secure entry to a secured area, identifies himself by speaking preset words into a microphone after which a comparator compares an electrical signal derived from the spoken words with a similar electrical signal derived from a version of the words which has been pre-recorded by the person. The record may be carried in a magnetic or other strip recording on a credit card or may be one of a number of recordings in a bank kept at a central station in telephonic communication with the purchase or entry point.

Description

SPECIFICATION Identification apparatus and method This invention relates to apparatus and methods for identifying individuals.

One application of the invention is the identification of a person seeking to obtain credit when making a purchase, perhaps offering a credit card, and the invention is also applicable to access control systems where access to a secured area can only be achieved by someone carrying an appropriate token, or otherwise being able to identify himself.

It is equally possible to use the system for verification that someone presenting himself for an interview or for an examination is, in fact, the person he says he is.

The invention arises from the discovery by the inventors that a voice print is a satisfactory means of identification in that no two people produce the same print, whereas one person can reproduce his print reliably.

According to one aspect of the invention, identification apparatus comprises a reader of a recording, a receiver of spoken information, and a comparator of signals derived from the reader and the receiver respectively. From another aspect the invention can be considered to reside in a method of identifying a person by comparing a voice signal of the person with a pre-recorded voice signal of the person.

Reference has been made above to spoken information and to a voice signal, and to a voice print, and to some extent these expressions are either synonymous or at least overlap. A voice print may be considered to be the sound of a particular person saying one or more words constituting spoken information, whereas a voice signal covers also an electrical or magnetic signal derived from a voice print and consisting perhaps of an analogue or digital signal possibly in an appropriately coded form.It will be appreciated that whereas an individual can often identify a person he knows from the sound of his voice, such identification cannot be carried out by a mechanical electrical or electronic comparator without the comparator first being supplied with a record derived from that person's speech, and probably also without both the recording and the voice print being used to provide voice signals in a similar form to enable the comparison to be made.

If an individual speaks some words into a microphone , an analogue electrical signal can be obtained and recorded, and then that can be processed for example by use of filters, frequency spectrum analysers, choppers and so on to produce a derived analogue signal, and that in turn could be used to produce a coded digital signal consisting of a number of values of the amplitude of the analogue signal at closely spaced time intervals. The recording itself may be of the original acoustic amplitude signal or of a derived signal, and then when the individual says the words again later, the same process can be used to produce an equivalent voice signal for direct comparison with the recorded signal in similar form by a comparator. Logic means may be programmed to give a YES signal if the degree of agreement between the two signals is fairly high, but a NO signal if the agreement is poor.

In one application where a person is attempting to obtain credit for making a purchase, a telephone call may be made to a remote station where there is a bank of prerecordings made by all the people operating on the system, each of whom has made a prerecording by speaking his own name, or speaking some set words. When the user wishes to be verified and says the words into the telephone again, a computer can quickly examine the bank of pre-recordings to see if they include the voice signal corresponding to that now being spoken, or possibly to see if the voice signal associated with the name or a number offered by that person agrees with the corresponding pre-recording. If there is correspondence it may be sufficient if a YES signal is given, but it may also be possible for further information stored in the bank to be released for display on a VDU at the purchase point.

The invention includes a bank of recordings each comprising an analogue or digital version of spoken information.

In another method of controlling credit, individuals on the system can be issued with credit cards which physically carry a recording, for example a magnetic recording of the voice speaking the selected words, or a recording of an analogue or digital derived voice signal. Then at the purchase point the card may be fed to the receiver and the person can read the relevant words into a microphone from which a voice signal is derived and then the comparator can give a YES signal if the user is able to reproduce the signal recorded on the card with reasonable faithfulness.In that application the equipment at the purchase point would include a converter capable of converting the speech into an electrical signal which can be read by the reader, but it is also possible to have a telephone or other link between the purchase point and such a converter, or comparator at a remote point where the comparison can be made, and from which the result of the comparison can be delivered by the telephone link to the purchase point.

The invention is also applicable to an access control system in which only authorised people are allowed to go through a door or into a secured area, and where there may be different levels of security for different people using the system.

If an authorised person is carrying a card with a voice print recorded on it, he can feed that into equipment at a door and speak the identifying words into a microphone at the door, and then if the spoken version matches the pre-recorded version a signal can be given to release a lock on the door.

Again if it is not desired to carry individual cards, the user can merely speak into the microphone at the door, and the coded ver sion of his speech can be compared with a pre-recorded version in a bank of pre-record ings either at the door or at a central station, and if it corresponds with any of the recorded versions, then a signal can be given to release the door lock.

The system will be very simple to use and reliable.

The accompanying drawings show in diagrammatic form some ways in which the invention can be carried into practice.

From another aspect the invention com prises a portable token carrying a recording of spoken information capable of being directly read from the token, the token being in a form easily carried in the pocket and offered to a reader, and perhaps also carrying identifying information.

The invention may be carried into practice in various ways, and four embodiments will now be described by way of example with reference to the accompanying drawings, in which: FIGURE 1 is a block diagram of a voice identification system capable of identifying a person by telephone; FIGURE 2 is a block diagram of a voice identification system in use to control access to a restricted area; FIGURE 3 is a block diagram of a similar system to that of FIGURE 2 which utilises individual identity cards as opposed to a central bank of records; FIGURE 4 is an elevation of an identity card as used in the system of FIGURE 3; FIGURE 5 is a block diagram of the equipment used for verifying the identity of a person at a point where a transaction is to be carried out; FIGURE 6 is a block diagram of the equipment used in enrolling a new person; and FIGURE 7 is a block diagram of a verification board used in each of the systems.

The main features of the invention which enable the system to be used for identification purposes are voice signal obtaining means 10, voice signal record means 20 comparison means 30 and confirmation signalling means 40, each of which appear in different forms within the four embodiments of the invention to be described. Reference to these various means will be made by utilising reference numerals which comprise the sums of the reference numerals above and a multiple of 100, in dependance upon which particular embodiment is being described. Therefore, the voice signal obtaining means 10 will be referred to as the microphone of a telephone 110 in the first embodiment, a microphone 210 in the second embodiment, and soon.

With reference now to FIGURE 1, an identification system is shown in diagrammatic form. One use of such a system may be made by a credit company and a series of shops. In such use, persons entitled to credit facilities would have recordings of their voice signals stored in the recordings bank 120, in a man ner to be described below. When a person wishes to utilise the credit facilities to purchase goods from one of the shops, all that is necessary to verify the person's entitlement to the credit facilities is for the shop to telephone the credit company. The person then provides a voice signal by speaking certain words into the telephone 110.This voice signal is received by receiver 1 50 at the credit company, and passed into a comparator 1 30. The comparator then either selects the persons prerecorded voice signal from the recordings bank 120 in accordance with address data supplied with the voice signal, giving the location of the pre-recorded voice signal,and compares it with the voice signal, or searches through the recordings bank comparing each pre-recorded voice signal in turn with the voice signal. A YES/NO response 140 from the comparator 1 30 in accordance with whether the voice signal and pre-recorded voice signal match is then passed back to the receiver 1 50, and then relayed via the telephone to the shop.

The persons credit rating may be manually checked by someone in the credit company by means of a visual display unit, 160, which receives details of the persons account from the recordings bank 120, and the response from the comparator 1 30.

FIGURE 2 depicts a similar system to that of FIGURE 1. However, in this layout the system is used to govern access to a restricted area. The person wishing to gain access provides a voice signal by speaking into the microphone 210; this signal is received by receiver 250 and passed to comparator 230.

Comparison between the voice signal and a pre-recorded voice signal, which is obtained from the recordings bank 220 is then made.

A response signal 240 in accordance with whether a favourable comparison of the voice signals occurs is then passed to the door lock 260 to release the lock if necessary.

A further embodiment of the invention is shown in FIGURE 3. This system is similar to that shown in FIGURE 2, with the exception that instead of a recordings bank containing several peoples pre-recorded voice signals, an identity card 320 caries the individual's prerecorded voice signal. To gain access in this system the person inserts the identity card 320 into a reader 325 which transmits the pre-recorded voice signal to the comparator 330. The person then speaks into the microphone 310 and the voice signal is then relayed to the comparator 330. If the signals compare favourably then the response signal 340 releases the electro-mechanical door lock 360, thus enabling the person to enter.

The pre-recorded voice signal of the person may be contained on a magnetic strip 370 which is carried on the identity card 320 as shown in FIGURE 4.

The recording is conveniently carried on three parallel tracks and consists of the individual speaking seven words converted to a digital recording. More space can be made available on the magnetic strip 370 for further information in digital form and that can be read at the same time as the voice print is read, provided additional standard equipment is installed with the invention.

It is convenient to describe at this juncture, the verification board shown in FIGURE 7.

That includes a pre-amplifier and amplifier 1 2 for an input whether from a microphone or from a card reader and the output from the amplifier 1 2 is fed as input to a spectrum analyser 1 3 which includes frequency filters and amplitude choppers. The particular analyser selected selects from the output of the amplifier 12, the signal components in the frequency range from 200 to 7000 Hz. The output is an analogue signal from which noise has been removed and that is supplied to an analogue-to-digital converter 14, which produces a binary coded digital version of the analogue signal consisting of a series of values of the signal amplitude at closely spaced intervals.The BCD output from the converter 14 can be stored in a random access memory (RAM) 1 5 associated with a microprocessor unit 16. In one embodiment the spectrum analyser 1 3 is identified as l.E.C. ASA 16 CP 5014 13281 and the converter 1 4 is identified as TMM20 16P-2.

The converter 14 can also be programmed to have its output stored in a read-only memory 26 associated with a microprocessor unit 1 7. The microprocessors 1 6 and 27 control the way in which the verification board is used in dependence on whether it is being used in enrolment equipment or verification equipment as will be described below. The board of FIGURE 7 also includes an interface 29 from which the output can be taken.

A new user enrolling on the system is required to produce his voice print and for that purpose attends an issuing centre containing enrolment equipment as shown in FIG URE 6. The person speaks into a microphone 24 repeating words which appear on a visual display unit 28 controlled via a keyboard 31.

The output from the microphone 24 is fed as input to the verification board 23 which is as already described with reference to FIGURE 7, and the output from the analogue-to-digital converter 14 on that board is stored in the RAM 15.

The person then repeats the sequence of words and the new version is fed to the amplifier 1 2. The output from the amplifier 1 2 is again passed through the analyser 1 3 and converter 14 and this time is stored in the ROM 26. The microprocessors 16 and 27 are programmed to compare the contents of the RAM 1 5 and the ROM 27 and if there is a fairly accurate match the recording stored in the RAM 1 5 is the one to be used for application to the record means 20. If there is not a very good match then the person is required to speak the words again until there is a reasonable match and it is known that the recording to be placed on the record means 20 is a fairly accurate representation of the persons speech.Once a satisfactory recording is stored in the RAM 15, that recording is transferred to the record means 20 by feeding the contents of the memory 1 5 through a converter and encoder 22 to a writer 21 which is capable of transferring the binary coded decimal digital signal onto the record means 20 which may be a magnetic strip, a floppy disc, a memory chip or any other form of storing an electrical signal. The encoder, which is capable of controlling the writer to make that recording, is the subject of a separate patent application.

Use of the verification board as comparison means will now be described with reference to an identification system which may be used to identify a person by means of an individual identity card within a shop. In this situation the person has to present the card at a transaction station which is generally as indicated in FIGURE 5.

The card is presented to a card reader 480 which reads the recording on the strip 370 (FIGURE 4) and feedsit to the comparator board 430 which is as shown in FIGURE 7, and is programmed so that the message carried on the credit card is stored in the RAM 15.

Then the user speaks into a microphone 410 at the transaction station and the output from the microphone is fed to the comparator 430 (FIGURE 7) which is programmed so that the output from the analogue-to-digital converter 14 is now fed to the ROM 26.

The microprocessor units 1 6 and 27 are programmed to compare the BCD signals in the memories 1 5 and 26 and if they are sufficiently alike to give an "accept" signal,whereas if they are quite unalike a "reject" signal is given and the people or equipment at the transaction station will act accordingly. If there is some similarity but not sufficient similarity, an indication can be given visually or by verbal command using speech synthesis asking the user to speak the words again into the microphone 410 so that a further attempt can be made to achieve a satisfactory comparison. If, after seven attempts, satisfactory comparison has not been achieved, then the application is finally re jected.

The invention works perfectly satisfactorily and is partly based on the surprising discovery that an individual's voice print will be sufficient identification of that individual in that whenever he repeats the same words, a very closely similar pattern of sounds is produced.

A particular selection of spectrum analyser 1 3 enables such a recording to be made.

Also, with a suitable encoder, as described above, a recording of a number of words and consisting in a preferred example of 456 bytes can be recorded on a length of magnetic strip not more than about three inches long.

While all users may attend an Enrolment Centre for the preparation of the recording to be applied to their card, it will be sufficient to have simpler equipment at each transaction station where that recording can be read and compared with a signal produced by the user at the microphone 410.

In a large shop, for example, the equipment at a number of transaction stations may consist of a card reader and a microphone connected to a common unit elsewhere in the building for all the other components including the recognition board 430.

The RAM and ROM may include floppy discs at the common central equipment.

In one convenient system the recorded message and the repetition at the transaction station should not last longer than 1.25 seconds per utterance or word, and there should not be longer than between 40 and 320 milliseconds between words. The speed of reading the card might be between 3 and 40 inches per second.

Claims (30)

1. Identification apparatus comprising a reader of a recording, a receiver of spoken information, and a comparator of signals derived from the reader and the receiver respectively.

2. Apparatus as claimed in Claim 1 in which the receiver includes a microphone.

3. Apparatus as claimed in either of the preceding claims in which the receiver includes means for deriving an analogue or digital signal from the spoken information.

4. Apparatus as claimed in Claim 2 and Claim 3 in which the deriving means is remote from the microphone.

5. Apparatus as claimed in any of the preceding claims in which the reader is arranged to read a recording from a disc or other bank of similar recordings.

6. Apparatus as claimed in Claim 5 in which the bank is remote from the receiver or a microphone constituting a part of the receiver.

7. Apparatus as claimed in any of Claims 14 in which the reader is arranged to read a recording from a portable token.

8. Apparatus as claimed in any of Claims 1,2,3,5, and 7 in which the equipment is all at one site

9. Apparatus as claimed in any of the preceding claims including a bank of recordings of analogue or digital versions of spoken information.

10. Apparatus as claimed in any of Claims 1-8 including a portable token carrying the recording as an analogue or digital version of spoken information.

11. Apparatus as claimed in any of the preceding claims in which the comparator is arranged to give a YES or NO signal independence on whether the signal derived from the spoken information is like or unlike the signal derived from the recording.

1 2. Apparatus as claimed in any of the preceding claims including a telephonic or radio communication link between a microphone constituting a part of the receiver, and the reader and/or the comparator.

1 3. Apparatus as claimed in any of the preceding claims in which a microphone constituting a part of the receiver is situated at an indentification point, for example a point of purchase or a point of access to a secured area.

14. Apparatus as claimed in Claim 1 3 including a telephonic or radio communication link between the identification point and the comparator and/or the receiver.

1 5. A portable token carrying a recording of spoken information capable of being directly read from the token.

16. A bank of recordings each comprising an analogue or digital version of spoken information.

1 7. Identification apparatus arranged substantially as herein specifically described with reference to any figure of the accompanying drawings.

1 8. A method of identifying a person by comparing a voice signal of the person with a pre-recorded voice signal of the person.

19. A method as claimed in Claim 18 in which the voice signals are obtained from the person speaking one or more specific words, respectively when making the pre-recording and at the time of identification.

20. A method as claimed in either Claims 18 and 19, in which the pre-recorded voice signal is recorded in analogue or digital form.

21. A method as claimed in any of Claims 18-20 in which the pre-recorded voice signal is recorded magnetically on a strip of tape, or a disc.

22. A method as claimed in any of Claims 18-20 in which the pre-recorded voice signal is recorded in a computer memory.

23. A method as claimed in any of Claims 18-22 in which the pre-recorded voice signal is stored at a record station as one of a bank of pre-recorded voice signals.

24. A method as claimed in any of Claims 18-23, in which the comparison is made by an electrical mechanical or electronic comparator.

25. A method as claimed in Claim 24 in which the comparator provides a signal which indicates whether the person's voice signal is like or unlike the pre-recorded voice signal.

26. A method as claimed in Claim 24 or Claim 25 in which the comparator is situated at the location where the person is speaking in making his voice signal.

27. A method as claimed in Claim 24 or Claim 25, in which the comparator is remote from the location where the person is speaking in making his voice signal.

28. A method as claimed in any of Claim!s 18-27, which is used to confirm the identity of a person wishing to obtain credit for the purchase of goods.

29. A method as claimed in any of Claims 18-27, which is used to confirm the identity of a person wanting to gain access to a restricted, or controlled area.

30. A method of identification performed substantially as herein specifically described with reference to any figure of the accompanying drawings.