FR2730579A1 - PORTABLE DEVICE INTENDED FOR VOCAL STIMULI DICTION EXERCISE - Google Patents

Abstract

A portable apparatus for practising the pronunciation of voice stimuli, such as stimuli for learning a foreign language. The apparatus is provided with an output (30) for delivering audio signals corresponding to said stimuli and to the responses from the user when the stimuli are transmitted, and an input (10) for receiving the audio signals corresponding to said responses. Said apparatus includes a bulk storage means (80) for recording said stimuli and a random access digital memory (70) for digitally recording the user response audio signals. Said bulk storage means consists of a programmable static non-volatile digital memory (80).

Description

 The present invention relates to a portable apparatus for the practice of uttering vocal stimuli, such as stimuli for learning a foreign language. The apparatus of the invention is in particular intended to constitute an individual language laboratory.

 Language labs are devices that usually consist of a control desk to which student units and units for the teacher are connected.

Students listen to an expression or phrase and, after listening, repeat it. They can still listen to a question and, in a later phase, they have to answer this quai In the rest of the description, the expressions, sentences and questions to which students are subjected are called stimuli and the answers they give to these questions. stimuli, the answers.

 The known apparatuses generally use, for the recording of stimuli and that of the answers, tape recorders, although for the stimuli, also know some supports that use disks. However, the use of tape recorders or devices of this type is restrictive insofar as it involves numerous manipulations to access the desired exercises or to listen several times to the stimuli or the desired responses. moreover, it implies the respect of a precise chronology in the order of the exercises and long periods of rewinding.

 The aforementioned drawbacks relating to the manipulations necessary for repeated listening of the same stimulus, and then of a response to this stimulus, are partly solved in document FR-A-2,538,599, which presents an apparatus capable of detecting the end of a recorded exercise, to rewind the tape, then to order a re-reading. Nevertheless, this device certainly solves the problem of the -ipulations necessary for the control of the tape recorder but does not solve those related to the rewinding time and the time of access to different exercises.

 Patent document US Pat. No. 4,391,929 provides a solution to the latter problem by proposing the use of a temporary static digital memory of the RAM (randoen access memory) type, storing, on the one hand, the last stimulus delivered by an associated tape recorder, and, on the other hand, the response of the user. By access to this memory, it is possible to listen to one or the other at will and, with almost instantaneous speed. But such a system assumes the frequent recording of stimuli in the memory which requires tedious manipulations. The use of a memory type RAM involves the loss of information stored when powering off the device unless to continue to supply energy. It must be added that the presence of a mechanical device such as a cumulative tape recorder with the conservation constraints of the data stored in the RAM type memory compromises the possibility of use as a portable device.

 It will be appreciated that the present invention aims at providing a portable apparatus which can be used individually and which completely overcomes the disadvantages encountered by the aforementioned language laboratory apparatus, namely the use of a tape recorder or any other other mechanical mass storage device.

The present invention therefore aims at an individual apparatus, that is to say one provided with an output for delivering audio signals corresponding to said stimuli as well as the responses given by the user to the emission of said stimuli, and an input for receiving the audio signals corresponding to said responses, said apparatus comprising a mass storage means for recording said stimuli and a digital random access memory for recording, in digital form, the audio signals of the speech responses; 'user,
According to the characteristic of the invention, said mass storage means consist of a programmable static digital permanent memory.

 According to another characteristic of the invention, said apparatus is provided with a second input provided for receiving audio signals corresponding to said stirrmli, said apparatus being provided to be able to record, in digital form, said stimuli in said permanent memory.

 According to another characteristic of the invention, said apparatus comprises a detector for the presence of audio signals on the first or the second input respectively corresponding to given responses of the stimuli and to said stimuli, said detector being provided for the recording of said audio signals in one or the other of the digital memories, and it further comprises a detector of absence of audio signals to control the interruption of said recording.

 According to another characteristic of the invention, said apparatus comprises a pulse detector provided for controlling the recording of the audio signals present on said second input and corresponding to stimuli, said pulses being signals of predetermined characteristics.

 According to another characteristic of the invention, said apparatus comprises manual means for interroning the recording of the audio signals in one or other of the digital memories.

 According to another characteristic of the invention, the audio signals recorded in the programmable digital permanent memory are free of any period of blank.

 According to another characteristic of the invention, each of a stimulus in the ROM is identified by pointers defined aut-tiquenent in real time during storage in said memory.

 According to another characteristic of the invention, each ~ = of a stimulus in the ROM is identified by pointers defined manually by the user when reading a record in the ROM.

 According to another characteristic of the invention, said apparatus is designed to operate in a scenario consisting of a plurality of repetitions of a sequence consisting of the following successive steps: a step of listening to a stimulus by the user, a step recording the response given by the user to this stimulus and a reading step dc the recorded response.

 According to another characteristic of the invention, said apparatus is designed to operate according to a scenario consisting of a plurality of repetitions of a sequence consisting of the following succcssie steps: a step of listening to a stimulus by the user, a step stemnt of the response given by the user to this stimulus, a step of listening to the stimulus by the user and a reading step of the recorded response.

 According to another characteristic of the invention, said apparatus is adapted to operate according to a scenario involving stimuli called questions and stimuli called corrections, said scenario knowing by the course of a first listening sequence of a stimulus question by the user and continuing through the course of a second sequence which consists of a plurality of repetitions of the following successive steps: a step of recording the response given by the user to this stimulus question, a reading step of the response will be by the user and a reading step of the stimulus correction associated with said stimulus question.

 According to another characteristic of the invention, said apparatus is provided for leakage according to a scenario consisting of a plurality of repetitions of a + previously recorded by Itutilisatur.

 According to another characteristic of the invention, said apparatus comprises manual means provided for interrupting or modifying the course of said scenario.

 According to another characteristic of the invention, said apparatus comprises a device for displaying curves, said apparatus being provided for reading samples of stimuli or responses in one or the other memory and for controlling, following this reading. the display on said display device of the curve representative of the amplitude of said samples as a function of time.

According to another characteristic of the invention, said apparatus is provided for -rna *
Displaying on said display device the curve representative of the amplitude in time of the audio signals present on the first input of said apparatus.

 According to another characteristic of the invention, said apparatus is controlled by a voice command circuit analyzing the audio signals present on the first input of said apparatus.

 According to another characteristic of the invention, the power supply of the device is cut off automatically while keeping the current phase of work in case of inactivity during a determined period.

 According to another characteristic of the invention, said permanent memory is an electrically erasable memory. Said memory may also be in the form of a plug-in memory card in said apparatus.

According to another characteristic of the invention, it comprises an interface whose input is connected to a rectr, said interface being provided to enable storage, in the memory
RAM or ROM, signals representative of stimuli or responses given to these stimuli and received by said receiver.

 According to another characteristic of the invention, it comprises an interface whose output is connected to a transmitter, said interface being provided to allow transmission by said transmitter of representative signals. stimuli or responses to these stimuli and stored in RAM or ROM.

The characteristics of the invention mentioned above, as well as others, are more clearly apparent on reading the following description of an exemplary embodiment, said description being made in relation to the appended drawings among which:
FIG. I is a schematic diagram of an apparatus according to the invention, and
FIGS. 2a to 2d are timing diagrams illustrating respectively the sequences of different operating scenarios of an apparatus according to the invention.

 The apparatus shown in FIG. I is provided with an input 10 for receiving an audio signal from a microphone (not shown) and a second input 20 for receiving an audio signal from a source such as a recorder, a radio, a player optical reading discs etc. n is further provided with an output 30 provided for delivering an audio signal on an earpiece or any other sound reproduction device.This apparatus comprises a control unit 60, for example a microprocessor DSP (digital signal processor), which is connected by a data bus 601 and an address bus 602 appropriate, on the one hand, to a mass memory, which according to the invention is a digital memory device 80 of the ROM type that can be rewritable or not by the user, and, on the other hand to a random access digital memory 70 of the RAM type. An input port 501 of the co-unit 60 is connected to the output of a digital-analog converter 50 whose input is connected, via the interface 40, to the inputs 10 and 20 of the apparatus. output 511 of the control unit 60 is connected to the input of a digital-to-analog converter 51 whose output is connected via the interface 41 to the output 30. The control unit 60 also has a port input 91 and output ports 101 and 111 to which are respectively connected manual control means such as a keyboard 90, a display device 100, and a warning device consisting essentially of three light-emitting diodes of different colors 110. The supply of each of the components of the apparatus is provided by a current source 120 such as a stand-alone power supply, for example a battery or an accumulator, or such as a power supply intended to be connected to the mains network.

 The ROM 80 is used to store the stimuli on the basis of a plurality of samples and the RAM for storing, as we shall see later, the user's responses.

 The use of a ROM 80 for storing the stimuli and a RAM 70 for storing the user's responses will allow almost instantaneous access to the sound samples stored in these memories. The use of a ROM 80 makes it possible for a large number of information to be stored therein in a non-volatile manner even in the case of total absence of energy, which makes it particularly interesting in the context of a portable use. Advantageously, because of its great ease and speed of programming, a ROM memory named in the field of technology in English terminology "flash memory".

 The control unit 60 essentially consists of a management unit 61, a data compressor 62, a data decompressor 63 and a special effects device. The compressor 62 is designed to deliver the compressed data in an adaptive differential pulse code modulation (ADPCM) format while the decompressor 63 is designed to receive compressed data in the ADPCM format and to deliver them in the PCM digital format. rme further comprises an audio signal presence detector 64 on one or the other of the inputs 10 or 20, an absence detector of audio signals 65 on one or the other of said inputs 10 or 20 and a detector of pulses 66. All the functions included in the control unit 60 can be realized logically.

 The input port 501 of the control unit 60 is connected to the input of the data compressor 62 whose output is connected to the management unit 61. The port 501 is still connected to the inputs of the detector 64, detector 65 and detector 66. The system management unit 61 is connected to the output port 511 via the data decompressor 63 and the special effects device 68.

We will now explain the operation of an apparatus according to the invention and to do this we will first consider recording the responses of the user to stimuli. These responses are in front of the microphone (not shown) connected to the first input 10. The analog signals from the microphone and present on duration 10 are transmitted, via the interface 40, to the converter 50 which proceeds to their sampling. and converting the samples into digital signals, for example PCM. These digital signals, present on the port 501 of the control unit 60, are transmitted to the compressor
ADPCM 62 as well as preecce detector 64 and audio absence detector 65.

The data leaving the compressor 62 is then transmitted to the management unit 61.

 Note that the detectors 64 and 65 do not detect the presence or absence of audio signals on the input 10 or 20, but rather deduce from the digital signals present on their respective inputs the presence or the absence of audio signals on the input. entry 10 or 20.

 When the audio signal presence detector 66, upon reading the samples on its input, detects the beginning of a response from the user, it transmits a pulse to the management unit 61 which then starts the recording process. in the RAM memory 70, ADPCM samples present at the output of the compressor 62. The first sample is stored at an address defined by the management unit 61 and incremented at the location of each new sample. address of the first sample of the response being stored is saved by the management unit 61 to form a marker pointer of the beginning of this response that will be used to read the samples during their return.

 When the detector of absence of audio signals 65, on reading the samples supplied to it, detects an absence of audio signal for a determined time, for example a second, it transmits a pulse to the management unit 61 which stops then the process of recording the samples in the RAM memory 70. The address is then decremented to the last value corresponding to a representative sample of a speech audio signal. This address is stored by the management unit 61 as the pointer of the end address of the response.

 We will now consider the reading stimulus of a stimulus or response by the user. Stimulus samples that are stored in the ROM 80 or response samples that are stored in the RAM 70 are read by the management unit 61 and are delivered to the input of the decompressor 63. They are then decompressed. and transmitted, via the output port 511 of the control unit 60, to the digital-to-analog converter 51 to be trinsmitted to the output 30 via the interface 41. An earphone or other playback device (not shown) is connected on exit 30 and allows the user to listen to or listen to stimuli or responses.

 It will be noted that upstream of the output port 511 of the control unit 60, the special effect camera 68 may possibly create signal distortions that would be desired by the user.

 When a process for reading a given response is requested, the management unit 61 reads the samples stored in the RAM memory 70 from the address of the pointer associated with said response, and up to address of the pointer marking the end of said answer.

 When a process for reading a specific stimulus is requested, the management unit 61 reads the samples stored in the ROM memory 80 from the address of the pointer associated with said stimulus, and this, to the address pointer marking the beginning of the next stimulus.

 The phase of recording the response of the user and the reading phase of this response which are respectively performed as just described are used alternately, according to different procedures or modes of operation, to constitute standard scenarios of which examples will now be detailed. The use of standard scenarios provides the user with a very simple mode of operation requiring minimal manipulation of the keys of the keyboard 90 to focus only on the intangible audio aspect.

 The first scenario, illustrated by FIG. 2a, consists of n repetitions, n having a default value (for example 3) which can be modified by the user by means of the keyboard 90, of the sequence SQ consisting of the following successive steps: a step ES listening stimulus by the user, an ER step of recording the response given by the user to this stimulus and a step LR of reading the response ene. This process occurs automatically for each stimulus stored in ROM 80.

 The second, illustrated in FIG. 2b, is based on the same principle, but with repetition of the SQ sequence consisting of the following successive steps: an ES step of listening to a stimulus by the user, an ER step of recording the response given by the user to this stimulus, an ES listening step of the stimulus by the user and a reading step LR of the recorded response. This process occurs automatically for each stimulus stored in ROM 80.

 In both cases, the user can manually switch to the following or previous stimuli before the end of the n repetitions, almost instantaneously, by pressing the "advance" or "backward" keys of the keyboard 90. The repetition of the current stimulus can also be ccmnsan: ée by pressing the key "repetition" of the keyboard 90.

The third scene, illustrated in FIG. 2c, involves stimuli called questions associated with stimuli called corrtctions. This scenario begins with a sequence
SQ1 consists of an ESQ step of listening to a question stimulus by the user. Then follows the sequence SQ2 consisting of a step ER of uegi of the response given by the user to the question stimulus, a step LR of reading the response segistrb and a step ESC listening of the corresponding correction stimulus by the user.
SQ2 is repeated n purposes, unless the user actuates the keys "advance", "recoil" or "repetition" of the keyboard 90 to resume the scenario at its beginning with respectively the following stimulus question, the stimulus question previous or stimulus question current.

 In the first three scenarios, the light-emitting diodes of different colors of the warning device 110 indicate to the user the phase of the outstanding sequence. In addition, the passage from one stimulus to another is indicated to the user by a brief signal sore. In case of non reaction of the user during a determined time of the ER phase, the current stimulus is repeated automatically.

 The fourth scenario, illustrated by FIG. 2d, consists of the repetition R of a record E, previously recorded by the user, until he presses a key on the keyboard 90 or there is a signal on the microplne. In this case, a new record E is stored in the ROM 80 and the scenario is resumed with said record E.

 The apparatus of the invention is provided for autoretrically repeating a scenario for each available stimulus.

 If there is no voice activity for a given period of time, the power supply to the device switches off automatically, keeping the current work phase and thus allowing the user to resume use at the point where it was stopped.

 The stimuli stored in the form of ADPCM samples in the ROM 80 may be registered by the user. This uwisbs is made from the second input 20 to which is connected a source such as a phone, a radio, an optical reading disc player, etc. The analog signals from the input 20 are transmitted, via the interface 40, to the converter 50 which proceeds to their sampling and the conversion of the samples into digital signals. The latter, present on the port 501 of the cononande unit 60, are transmitted to the compressor 62 as well as to the detector 64, to the detector 65 and to the detector 66. The data coming out of the compressor 62 are then transmitted to the control unit. Bestion 61.

 There are three ways of recording stimuli by the user.

 The first is fully automatic and its operation is as follows. When the audio signal presence detector 64, upon reading the samples on its input, detects the start of a stimulus, it transmits a pulse to the management unit 61 which then starts a recording process, in the memory RAM 70, samples present at the output of the compressor 62. The first sample will be stored at a first address defined by the management unit 61 and incremented for each new sample. This process continues until the moment the detector absence of audio signals 65, on reading the samples on its input, detects a lack of signal for a given time, for example a second. The detector 65 transmits a pulse to the management unit 61 which then stops the process of recording the samples in the RAM. The address is then decremented to an end address that points to a representative sample of a speech signal.

The process is then continued by transferring to the ROM 80 samples that are stored in RAM 70 between the first address and the end address. The first storage address in the ROM 80 is determined by the management unit 61 and is saved by it to form a reference pointer of the beginning of the stimulus
Similarly, the end address is saved and will serve as pointer cue the end of this stimulus but also as a pointer to the start address of the next stimulus that will be stored. It can be considered that the addresses of the pointers are defined by the management unit 61 automatically in real time.

It will be noted that the recording of the samples of the RAM memory in the memory
ROM can be done with a few seconds of offset compared to the recording of the same samples in the RAM memory, the duration of this offset being at least equal to the detection time of absence of signal by the detector 65.

 The second mode of registration, also automatic, concerns the recording from a specially prepared medium with markers in the form of pulses of determined characteristics and is usable for both dialogs and exercises. The process of saving samples in ROM 80 is substantially the same as before. It starts, however, when the pulse detector 66 has transmitted to the management unit 61 a pulse indicating that it has detected the presence of a marker.

 The third mode functions as the first mode except for the fact that the recording process is interrupted when the user actuates a key on the keyboard 90 and restarts as soon as a new stimulus has been set.

 In these two modes, as in the first, only the representative samples of a speech signal are recorded in the ROM 80.

 The stimuli recorded in the ROM 80 can be classified a posteriori. The text composed of the different stimuli desired by the user is stored in the ROM 80 as has been explained. The user can, during the reading of said text, actuate a key of the keyboard 90 to save, in the management unit 61, the addresses of the first samples of said stimuli which then form markers for locating said addresses.

 The recording of new stimuli in the ROM memory 80 may require the prior erasure of sufficient space therefrom, especially if there is no more available. In the case of the use of an electrically erasable permanent memory, it is e controlled by the action of predetermined keys of the keyboard 90. To avoid an unwanted erasure command, the user may be asked to dial a security code with the keys of said keyboard 90. The ROM 80 can also allow the storage of answers given by the user if he wishes to keep them in a sustainable manner.

 An alternative embodiment of an apparatus may not provide for the recording of stimuli by the user. In this variant, high-capacity interc-memory memories will be used in the form of "memory cards", said memories being intended to contain all the exercises of a complete language course, for example. Said cartridges can be plugged into a space provided for this purpose on the housing of the device.

The management unit 61 can read all the samples constituting a stimulus in the ROM 80 to calculate the amplitude curve thereof as a function of time and control the display of this curve on the display device. 110. Similarly, she can read
the samples from the RAM 70 or the samples present on the port 501 of
the control unit 60 for calculating the amplitude curve thereof as a function of time and as the display of this curve on the display device 110.Thus the user can compare the level variations of the stimulus read and of the answer that he records or has already recorded and thus to take into account the words or syllables to accentuate during the pronunciation.

 It should be noted that the keyboard 90 can be replaced by any human-machine interface circuit, such as a voice control circuit 67 provided for receiving the signals present on the port 501 and for transmitting an ode pulse to the signal unit. management 61.

The circuit 67 analyzes, on reading the samples supplied to it, the messages that are present, in the form of audio signals, on the input 10 of the apparatus, and if the message analyzed corresponds to a command as by said circuit it transmits a control pulse to the management unit 61 which then performs the appropriate command. Advantageously, the analysis of the signals present on the input 10 takes place during the emission of a stimulus per device, so as not to confuse a voice command with a response to a stimulus.

 In an advantageous variant embodiment, the apparatus is provided with an interface 42 which is connected, by a bus 603, to the management unit 61. The interface 42 has an input which is connected to a receiver 44, by example of the optical type such as an infrared receiver, to receive coded electromagnetic signals. These signals are, for example, representative of stimuli or responses given to these stimuli.

 H further comprises an interface 45 which is connected to the management unit 61 by a bus 604 and whose output is connected to a transmitter 46, for example of the optical type such as an infrared transmitter, for transmitting coded electromagnetic signals. These signals are, for example, representative of stimuli or responses given to these stimuli respectively stored in the ROM 80 or in the RAM 70.

 It is then possible to load in one of the RAMs 70 or ROM 80 stimuli or responses from the receiver 44 and to emit responses or stimuli from the RAM 70 or the ROM 80 by the transmitter 46.

Claims (21)

 1) A portable apparatus for speech stimulus exercise, such as stimuli for learning a foreign language, said apparatus being provided with an output (30) for delivering audio signals corresponding to said stimuli as well as the responses given by the user to the emission of said stimuli, and an input (10) for receiving the audio signals corresponding to said responses, said apparatus comprising mass storage means (80) for the purpose of said stimuli and a random access memory (70) for digital recording of the user response audio signals, characterized in that said mass storage means is a static digital permanent memory. programmable (80).  2) Apparatus according to claim 1, characterized in that it is provided with a second input (20) for receiving audio signals corresodant said stimuli, said apparatus being provided to be able to record, in digital form, said stimuli in said memory pmnnente (80).  3) Apparatus according to claim 2, characterized in that it comprises an audio signal presence detector (64) on the first input (10) or on the second input (20) respectively corresponding to responses given to stimuli and said stimuli, said detector (64) being arranged to control the recording of said audio signals in one or the other of the digital memories (70 or 80) and in that it comprises a signal absence detector (65 ) to control the interruption of said recording.  4) Apparatus according to claim 2, characterized in that it comprises a pulse detector (66) provided for controlling the recording of audio signals present on said second input (20) and corresponding to stimuli, said pulses being signals of predetermined characteristics.  5) Apparatus according to one of the preceding claims, characterized in that it comprises manual means (90) for interrupting the recording of audio signals in one or the other memory (70 or 80).  6) Apparatus according to one of claims 3 to 5, characterized in that the audio signals recorded in the programmable digital permanent memory (80) are free of any period of white.  7) Apparatus according to one of the claims -côents, characterized in that each stimulus of a stimulus in the ROM (80) is spotted by pointers automatically in real time when stored in said memory.  8) Apparatus according to one of the preceding claims, characterized in that each recording of a stimulus in the ROM (80) is marked by pointers manually set by the user when reading a record in the ROM ( 80).  9) Apparatus according to one of the preceding claims, characterized in that it is intended to operate according to the automatic repetition, for each available stimulus, a scenario consisting of a plurality of repetitions of a sequence (SQ) consisting of successive steps following: a step (ES) for listening to a stimulus by the user, a step (ER) of recording the response given by the user to this stimulus and a reading step WR) of the recorded response.  10) Apparatus according to one of the preceding claims, characterized in that it is intended to operate according to the automatic repetition, for each available stimulus, a scenario consisting of a plurality of repetitions of a sequence (SQ) consisting of successive drapes following: a step of listening to a stimulus (ES) by the user, a step (ER) of recording the response given by the user to this stimulus, a step (ES) of listening to the stimulus by the user and a step (LR) of reading the recorded response.  11) Apparatus according to one of the preceding claims, characterized in that it is intended to operate according to the automatic repetition, for each available stimulus, a scenario involving stimuli called questions and stimuli said answers. This scenario begins with a sequenced (SQ1) sequence of a step (ESQ) listening to a stimulus question by the user. Then follows the sequence of the sequence (SQ2) consisting of a step (ER) of recording the response given by the user to the question stimulus, a step (LR) of reading the response and a response. step (ESC) of listening to the corresponding stimulus correction by the user.  12) Apparatus according to one of the preceding claims, characterized in that it is intended to operate in a scenario consisting of a plurality of repetitions (R) of a record (E) recorded previously by the user.  13) Apparatus according to one of oev-iicttions 9 to 12, characterized in that it comprises manual means (90) provided to interrupt or modify the automatic operation of said apparatus.  14) Apparatus according to one of the preceding claims, characterized in that it comprises a device for displaying curves (110), said apparatus being provided for reading samples of stimuli or responses in one or the other memory ( 70 or 80) and to control, following this reading, the display on said display device (110) of the representative amplitude curve of said samples as a function of time.  Apparatus according to claim 14, characterized in that the display on said display device (110) of the amplitude-versus-time curve of the audio signals present on the first one is provided for coenmnding the display. input (10) of said apparatus.  16) Apparatus according to one of the preceding claims, characterized in that it is controlled by a voice control circuit (67) for analyzing the audio signals present on the first input of said apparatus.  17) Apparatus according to one of the preceding claims, characterized in that in case of inactivity during a detracted period, its power is automatically cut maintaining the working phasme in progress.  18) Apparatus according to one of the preceding claims, characterized in that said permanent memory (80) is an electrically erasable memory.  19) Apparatus according to one of the preceding claims, characterized in that said memory peimanente (80) is in the firm of a memory card plug in said appai.  20) Apparatus according to one of the preceding claims, characterized in that it comprises an interface (42) whose input is connected to a receiver (44), said interfa (42) being to enable storage, in the RAM memory ( 70) or in the ROM (80) signals representative of stimuli or responses given to these stirnli and received by said receiver (42).  21) Apparatus according to one of the preceding claims, characterized in that it comprises an interface (45) whose output is connected to a transmitter (46), said interface (45) being provided to allow transmission by said transmitter (46). ) signals representative of stimuli or responses given to these stimuli and stored in the RAM (70) or in the ROM (80).