Abstract:
The voice-based manipulation apparatus includes a storage section for storing voice information for specifying manipulation targets. A manipulation section manipulates the manipulation target that is associated with the voice information stored in the storage section. A search section searches the voice information stored in the storage section in association with the manipulation target and presents resultant voice information. The voice-based manipulation method includes storing voice information for specifying manipulation targets in a storage section; manipulating the manipulation target which is associated with the voice information stored in the storage section; and searching the voice information stored in the storage section in association with the manipulation target.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a voice-based manipulation technique capable of controlling and manipulating electronic devices or the like through input voices, and, more particularly, to a voice-based manipulation method and apparatus, which allow even a user who does not remember registered words to easily check the correlation between registered words and subjects to be manipulated, thereby improving the operability. 
     2. Description of the Related Art 
     Voice-based manipulation techniques which permit a user to manipulate electronic devices or the like through input voices have been proposed. Meanwhile, some improvements on speech recognition techniques have also been made. With such improved speech recognition techniques, there are active developments of electronic devices or the like which use voice-based manipulation techniques. 
     For example, there is known an on-board audio system for a vehicle, which can be manipulated with voices in the following manner. Using this audio system, a user registers voice data for each of the channel frequencies of broadcasting stations. When the user utters some words corresponding to one of the registered voice data, the audio system recognizes the uttered words through a speech recognition technique and automatically tunes itself to the designated channel frequency. 
     More specifically, the user tunes in to the channel frequency of a desired broadcasting station and utters words, for example, “first broadcasting station”, by manipulating a voice registration button provided on the on-board audio system, and then voice data of the words “first broadcasting station” can be stored (registered) in a memory in association with that channel frequency. In a similar fashion, the user tunes the audio system to the channel frequencies of other broadcasting stations and utters words, such as “second broadcasting station” and “third broadcasting station”. As a result, voice data of the words “second broadcasting station”, “third broadcasting station” and so forth can be stored in the memory in association with the tuned channel frequencies. When, after this voice registering operation, the user utters one stream of words, selected from the registered groups of words, such as “first broadcasting station”, “second broadcasting station” and “third broadcasting station”, the audio system recognizes the voiced words and automatically tunes itself to the designated channel frequency. 
     As mentioned above, this on-board audio system can permits voice-based manipulation to be performed based on voice data that has been registered beforehand in association with subjects to be manipulated (hereinafter referred to as “manipulation targets”). But, users are likely to forget registered words or forget the correlation between the registered words and manipulation targets. In this case, each user may have to, for example, repeat the above-described voice registering operation to change old voice data stored in the memory to new voice data. 
     It is desirable to ensure voice registration of any words, not specific words, thereby improving the operability for users. If such a highly general-purpose design is taken, the designed audio system, though effective in many ways, would suffer a lower operability, because users are apt to forget registered words. 
     While the tuning operation of an on-board audio system has been specifically discussed to show the problem of the conventional voice-based manipulation techniques, the same problem arises in the case where a user who is likely to forget registered words loads a recording/reproducing medium in an MD (Mini Disc) player, CD (Compact Disc) player or the like, which is installed in an on-board audio system and selects a musical piece, a title or the like, recorded on that medium, with voices. 
     The factor that users may forget registered words is the problem that should be overcome not only for on-board audio systems for vehicles but also the voice-based manipulation techniques. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a voice-based manipulation method and apparatus, which allow even a user who has forgotten registered words to easily check the correlation between registered words and manipulation targets, thereby ensuring an improved operability. 
     To achieve the above object, according to one aspect of this invention, there is provided a voice-based manipulation apparatus which comprises a storage section for storing voice information for specifying manipulation targets in association with the manipulation targets; a manipulation section for, when a voice is supplied, manipulating the manipulation targets which is associated with the voice information stored in the storage section which corresponds to the voice; and a search section for searching the voice information stored in the storage section in association with the manipulation target and presenting the resultant voice information. 
     According to another aspect of this invention, there is provided a voice-based manipulation method which comprises the steps of storing voice information for specifying manipulation targets in a storage section in association with the manipulation targets; manipulating, when a voice is supplied, the manipulation targets which corresponds to the voice; and searching the voice information stored in the storage section in association with the manipulation target and presenting resultant voice information. 
     With the above structures, a user can acquire voice information which is searched and presented by the search section (or the searching step). Even if the user forgets, or is uncertain abut, voice information stored (registered) in the storage section, the user can easily check the correlation between the voice information and the manipulation target which is associated with that voice information. Even when the user does not remember voice information, therefore, it is unnecessary to store voice information again in the storage section, resulting in an improved operability. 
     It is preferable in the above voice-based manipulation apparatus and method that, in response a search instruction externally supplied, the search section or the searching step should detect an active manipulation target, search for that voice information which is associated with the detected active manipulation target and present the searched voice information. 
     In this case, when voice information associated with the active manipulation target is not stored in the storage section, the search section or the searching steps may search other voice information stored in the storage section in association with the manipulation target and present the searched voice information. 
     In the above two preferable modes, it is further preferable that in response to the search instruction externally supplied, the search section or the searching step should search the voice information stored in the storage section in a predetermined order in association with the manipulation target and present the searched voice information. 
     In this case, the predetermined order may be an alphabetical order, a forward sort direction or a reverse sort direction. 
     In the voice-based manipulation apparatus according to the first aspect, the voice-based manipulation method according to the second aspect, or any one of the above-described preferable modes, the storage section can store the voice information again and may store a supplied voice as voice information associated with an active manipulation target at the time of storing the voice information again. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects and advantages of the invention will become readily apparent from the following description, taken in conjunction with the accompanying drawings, wherein: 
     FIG. 1 is a plan view showing the outer appearance of a voice-based manipulation apparatus according to one embodiment of this invention; 
     FIG. 2 is a block diagram illustrating the structure of a signal processor incorporated in a voice control unit; 
     FIGS. 3A through 3C are diagrams respectively showing individual memory maps of a title designation voice data memory table, a unit designation voice data memory table and an equalizer-adjustment voice data memory table; 
     FIGS. 4A and 4B are explanatory diagrams illustrating the functions of a normal registration/voice-based operation key; 
     FIGS. 5A and 5B are explanatory diagrams illustrating the functions of a unit registration/search key; 
     FIGS. 6A and 6B are explanatory diagrams illustrating the functions of an equalizer-adjustment voice registration/search key; 
     FIGS. 7A and 7B are explanatory diagrams illustrating the functions of a volume control/guidance language switching key; 
     FIGS. 8A and 8B are explanatory diagrams illustrating the functions of a search/forward scan key; 
     FIGS. 9A and 9B are explanatory diagrams illustrating the functions of a search/reverse scan key; 
     FIG. 10 is a flowchart illustrating the operation of the voice-based manipulation apparatus according to this embodiment in standby mode; 
     FIG. 11 is a flowchart showing the operation of the apparatus in voice registration mode; 
     FIG. 12 is a flowchart showing the operation of the apparatus in unit designation voice registration mode; 
     FIG. 13 is a flowchart showing the operation of the apparatus in equalizer-adjustment voice registration mode; 
     FIG. 14 is a flowchart illustrating the operation of the apparatus in voice-based manipulation mode; and 
     FIGS. 15A and 15B are flowcharts illustrating the operation of the apparatus in registered voice data search mode. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to the accompanying drawings, a description will now be given of a preferred embodiment of the present invention as adapted to a voice-based manipulation apparatus that allows a user to perform the voice-based manipulation of an on-board audio system for a vehicle which is equipped with a reception tuner for receiving radio broadcast waves or the like, an MD player for playing an MD, a CD player for playing a CD, an equalizer for adjusting a frequency characteristic, an amplifier for controlling the volume and so forth. (Those components of the on-board audio system will hereinafter be called “audio units”. ) 
     FIG. 1 shows the outer appearance of a voice-based manipulation apparatus  1 , and FIG. 2 illustrates the structure of a signal processor which is incorporated in a voice control unit  2 . 
     Referring to FIG. 1, the voice-based manipulation apparatus  1  comprises the voice control unit  2 , which is the main unit to control the aforementioned individual audio units, a microphone  3  through which a user inputs a voice to give an instruction to the voice control unit  2 , and a remote operation section  4 . 
     The remote operation section  4  has a small speaker  5  and push-button type operational button switches  6  to  11 . The operational button switch  6  is called a “normal registration/voice-based operation key”, the operational button switch  7  a “search/forward scan key”, the operational button switch  8  a “search/reverse scan key”, the operational button switch  9  a “unit registration/search key”, the operational button switch  10  an “equalizer-adjustment voice registration/search key”, and the operational button switch  11  a “volume control/guidance language switching key”. Those keys have predetermined functions which will be discussed later. 
     As shown in FIG. 2, the microphone  3  and the remote operation section  4  are connected to a connector  14  of the voice control unit  2  via connection cables  12  and  13 , respectively. 
     Referring to FIG. 2, the voice control unit  2  includes an amplifier (microphone amplifier)  15 , a speech recognizer  18  and a voice data memory  19 . As the user utters words, a voice signal is supplied from the microphone  3  to the microphone amplifier  15  via the connection cable  12 . The microphone amplifier  15  amplifies the voice signal and sends it to the speech recognizer  18 . The speech recognizer  18  performs speech recognition on the received voice signal. The voice data memory  19 , which is a non-volatile memory, stores voice data recognized by the speech recognizer  18 . 
     The voice data memory  19  has a title designation voice data memory table  19   a , a unit designation voice data memory table  19   b , an equalizer-adjustment voice data memory table  19   c , and a guidance data memory table  19   d . The first three tables  19   a  to  19   c  store the voice data supplied from the speech recognizer  18 . The last table  19   d  prestores voice guidance data for generating voice guidances which will be discussed later. 
     As exemplarily shown in FIG. 3A, the title designation voice data memory table  19   a  is provided to store (register) information, such as a musical piece, which is being played by an active or currently operating audio unit, its title and the channel frequency of a broadcasting station, in association with data of voices uttered by the user (voice data). The unit designation voice data memory table  19   b , as exemplarily shown in FIG. 3B, serves to store (register) the name of an audio unit in operation in association with data of voices uttered by the user (voice data). As exemplarily shown in FIG. 3C, the equalizer-adjustment voice data memory table  19   c  serves to store (register) information on the setting state of the. equalizer and the set positioning in association with data of voices uttered by the user (voice data). 
     The voice control unit  2  further includes an amplifier (speaker amplifier)  16 , an imitation sound generator  17 , a voice synthesizer  20 , a controller  21 , an interface (I/F) circuit  22  and an interface port  23 . 
     The imitation sound generator  17  generates an imitation sound signal, such as “Peep” or “Beep”. The voice synthesizer  20  generates a guidance voice signal based on the voice data or the voice guidance data stored in the voice data memory  19 . The speaker amplifier  16  amplifies those guidance voice signal and imitation sound signal and sends the amplified signals via the connection cable  13  to the speaker  5  in the remote operation section  4 . 
     The controller  21  receives operation signals from the individual operational button switches  6 - 11  via the connection cable  13  and controls the individual audio units. The I/F circuit  22  and the interface port  23  permit bidirectional communications between the controller  21  and each audio unit. 
     The controller  21  is provided with a microprocessor which runs a preset system program to control the general operation of the voice-based manipulation apparatus  1  and the operations of the individual audio units. 
     The operation of the voice-based manipulation apparatus  1  with the above-described structure will be discussed below referring to FIGS. 3A to  15 B. FIGS. 3A through 3C respectively show the individual memory maps of the title designation voice data memory table  19   a , the unit designation voice data memory table  19   b  and the equalizer-adjustment voice data memory table  19   c . FIGS. 4A through 9B are explanatory diagrams illustrating the functions of the operational button switches  6 - 11 . FIGS. 10 through 15 are flowcharts for explaining operational examples of the voice-based manipulation apparatus  1  when the user operates the operational button switches  6 - 11 . 
     As illustrated in FIGS. 4A through 9B, when the user depresses one of the operational button switches  6 - 11  for a short time or for 2 or more seconds, the mode that matches with the user&#39;s operation is set. 
     According to this embodiment, the modes are classified into three kinds of modes: a registration mode for previously registering voice data necessary for voice-based manipulations in the title designation voice data memory table  19   a , the unit designation voice data memory table  19   b  and the equalizer-adjustment voice data memory table  19   c ; an operation mode for ensuring voice-based manipulations as the user utters voices corresponding to the voice data that are registered in those voice data memory tables  19   a - 19   c ; and a search mode for allowing the user to check the voice data registered in those voice data memory tables  19   a - 19   c.    
     In FIG. 10, as the main power source of an on-board audio system is switched on, the voice-based manipulation apparatus  1  is automatically powered on and the controller  21  stands by until one of the operational button switches  6 - 11  is operated (steps  100  to  120 ). When the user manipulates one of the operational button switches  6 - 11  for a short time or for 2 or more seconds during this standby process, the mode that corresponds to the user&#39;s operation is set, as shown in FIGS. 4A through 9B. 
     When it is determined in step  102  that the normal registration/voice-based operation key  6  has been continuously depressed for 2 or more seconds, the mode is set to the voice registration mode and the operation goes to a routine shown in FIG.  11 . In voice registration mode, first, the controller  21  sets “1” to a program counter constructed by the system program and carries out a sequence of processes starting at step  200 . 
     In step  200 , the voice synthesizer  20  reads predetermined voice guidance data from the guidance data memory table  19   d  and generates a guidance voice signal, and the imitation sound generator  17  generates an imitation sound signal of “Peep”. 
     The controller  21  supplies those guidance voice signal and imitation sound signal to the speaker amplifier  16  and reproduces “Register title . . . Peep”, which is a guidance sound comprised of a guidance voice and imitation sound, from the speaker  5 , requesting the user to utter a voice to be registered. 
     In the next step  202 , the speech recognizer  18  initiates a speech recognition process. When the user utters desired words in response to the guidance sound, the speech recognizer  18  detects the beginning of this voice generation, at which point a program timer in the controller  21  is activated so that the speech recognizer  18  is controlled to execute speech recognition of the voice uttered within 2.5 seconds. 
     More specifically, before giving the guidance sound, the speech recognizer  18  measures sounds (power of ambient sounds) which are picked up by the microphone  3  and are input via the microphone amplifier  15 , and sets the power level of the ambient sounds as a noise level. The output signal of the microphone amplifier  15  is added up every 10 milliseconds. Each added value is measured as a sound power level, and then a first threshold value THD 1 , which is higher than the power level of the ambient sounds, is set every 10 milliseconds. 
     When the user utters a voice, the speech recognizer  18  compares the level of the uttered voice (voice power) with the latest first threshold value THD 1  and determines the point when the level of the uttered voice becomes greater than the first threshold value THD 1  as the beginning of voice generation. The program timer is activated at the beginning of voice generation, and the speech recognizer  18  recognizes the voice uttered within 2.5 seconds and generates voice data corresponding to the recognition result. 
     At this point, the speech recognizer  18  further compares the level of the uttered voice (voice power) with a second threshold value THD 2  (fixed value) which is preset higher than the first threshold value THD 1 , and determines that speech recognition has been carried out properly when the voice power becomes greater than the second threshold value THD 2 . That is, when the level of the uttered voice becomes higher than the latest first threshold value THD 1  and then becomes higher than the second threshold value THD 2 , the uttered voice is taken as the subject to be recognized. This allows the property of the uttered voice which is less influenced by noise to be extracted accurately, thus improving the precision of speech recognition. 
     In the next step  204 , it is determined from the action of the timer or a variation in level whether or not speech recognition has been completed. Then, it is determined if speech recognition has been performed properly in step  206 . This decision is made by checking if the level of the uttered voice (voice power) input as a recognition target has been higher than the first and second threshold values THD 1  and THD 2 . When it is determined that speech recognition has been done properly, the flow goes to step  208 . 
     In step  208 , the controller  21  receives information of an audio unit in operation and information which is currently reproduced by that audio unit via the I/F circuit  22  and the interface port  23 , and stores the received data and the voice data generated by the speech recognizer  18  in the title designation voice data memory table  19   a  in association with each other (in combination). 
     Suppose that the audio unit in operation is a CD player which is currently playing a musical piece or the like on track  1  of a recording/reproducing medium (CD). If the user utters a word “one” in step  202 , the received data becomes “disc 1  track 1 ” and the voice data has word information of “one”. Those received data and voice data are stored (registered) as registered voice data in the title designation voice data memory table  19   a  in association with each other. 
     As another example, suppose that the audio unit in operation is a radio tuner which is currently tuned to a broadcasting station having a channel frequency of 76.1 MHz. If the user utters a word “seven” in step  202 , the received data about the channel frequency of 76.1 MHz and the voice data “seven” are stored (registered) as registered voice data in the title designation voice data memory table  19   a  in association with each other. 
     In other words, in voice registration mode, voice data corresponding to the voice uttered by the user is registered in the title designation voice data memory table  19   a  in association with information, such as the musical piece that is currently played by an audio unit in operation and the title of the musical piece or the received channel frequency, as shown in FIG.  3 A. 
     When the registration of voice data is completed, the flow advances to step  210  where the voice synthesizer  20  reads predetermined voice guidance data from the guidance data memory table  19   d  and generates a guidance voice signal. The controller  21  supplies the guidance voice signal to the speaker amplifier  16  and reproduces a guidance sound, “Registered”, from the speaker  5 , informing the user of the end of the registration. After the voice registration mode is completed, the operation goes again to the standby mode and starts the routine in FIG. 10 again at step  100 . 
     When it is determined in step  206  that speech recognition has not been done properly, the flow moves to step  212 . In step  212 , the controller  21  checks the value of the program counter to determine if the check is the second time. If it is the second time, the flow goes to step  214 . 
     In step  214 , the imitation sound generator  17  generates an imitation sound signal of “Beep Beep”. The controller  21  sends this imitation sound signal of “Beep Beep” to the speaker amplifier  16  and then outputs a guidance sound of “Beep Beep” from the speaker  5 , notifying registration failure. When the voice registration mode is ended, the operation comes again to the standby mode and starts the routine in FIG. 10 again at step  100 . In other words, if the property of the uttered voice cannot be extracted accurately due to the influence of noise or the like, the user should perform the registering operation from the start. 
     When it is determined in step  212  that the value of the program counter is “1”, the flow goes to step  216 . In step  216 , the measured value of the program timer is checked to determine whether or not the voice registration has taken 2.5 seconds or longer. 
     When the voice registration has taken 2.5 seconds or longer, the voice synthesizer  20  reads predetermined voice guidance data from the guidance data memory table  19   d  and generates a guidance voice signal, and the imitation sound generator  17  generates an imitation sound signal of “Beep”. The controller  21  supplies those guidance voice signal and imitation sound signal to the speaker amplifier  16  and reproduces “Beep . . . Too long” from the speaker  5 , warning the user that the time for the voice registration is too long. 
     If the voice registration mode has not been carried out properly due to some other factors, the voice synthesizer  20  reads predetermined voice guidance data from the guidance data memory table  19   d  and generates a guidance voice signal, and the imitation sound generator  17  generates an imitation sound signal of “Beep”. Then, the controller  21  supplies those guidance voice signal and imitation sound signal to the speaker amplifier  16  and reproduces “Beep . . . Try again” from the speaker  5 , requesting the user to make voice input again. 
     When this notification is completed, “2” is set in the program counter and the operation restarts at step  200  to allow the user to utter desired words again. In other words, the step  216  mainly gives a warning to the effect that the way the user utters a voice by has not been adequate. When the user properly utters intended words again in response to this warning, the voice data is registered in step  208 . Therefore, the user can register adequate voice data without manipulating the normal registration/voice-based operation key  6  again, which demonstrates an improved operability. 
     Once the user continuously depresses the normal registration/voice-based operation key  6  for 2 or more seconds, merely uttering words according to a guidance sound can cause the words uttered by the user to be registered in the title designation voice data memory table  19   a  in association with information, such as the musical piece that is currently played by an audio unit in operation and the title of the musical piece or the channel frequency of a broadcasting station. That is, it is possible to make voice registration of the information itself that the user wants, not the name of an audio unit. After this registering operation, the user has only to utter words corresponding to any registered voice data in order to ensure voice-based manipulation (whose details will be given later) for designating the musical piece, the title thereof, the broadcasting station and so forth. 
     A description will now be given of the operation in the case where it is determined in step  104  that the unit registration/search key  9  has been continuously depressed for 2 or more seconds. When the depression of this key  9  continues for 2 or more seconds, the mode is set to the unit designation voice registration mode and the operation goes to a routine shown in FIG.  12 . 
     In unit designation voice registration mode, first, the controller  21  sets “1” to the program counter constructed by the system program and carries out a sequence of processes starting at step  300 . 
     In step  300 , as in step  200  in FIG. 11, a guidance sound of “Register unit name . . . Peep” is reproduced, requesting the user to utter a voice to be registered. 
     In the next step  302 , as in step  202 , the speech recognizer  18  initiates a speech recognition process. When the user utters desired words in response to the guidance sound, the speech recognizer  18  detects the beginning of this voice generation, at which point the program timer in the controller  21  is activated so that the speech recognizer  18  is controlled to execute speech recognition of the voice uttered within 2.5 seconds. 
     After the end of speech recognition is confirmed in the next step  304 , it is determined in step  306  if speech recognition has been performed properly as done in step  206 . When it is determined that speech recognition has been done properly, the flow goes to step  308 . 
     In step  308 , the controller  21  detects an audio unit in operation and stores the detected data and the voice data generated by the speech recognizer  18  in the unit designation voice data memory table  19   b  in association with each other (in combination). 
     Assuming that the audio unit in operation is a CD player, when the user utters a word “CD” (si:di:) in step  302 , the detected data becomes “cd” and the voice data has word information of “si:di:”. Those detected data and voice data are stored as registered voice data in the unit designation voice data memory table  19   b  in association with each other. 
     Assuming that the audio unit in operation is a radio tuner, as another example, when the user utters a word “tuner” (t(j)u:nθ∂r) in step  302 , the detected data becomes “t(j)u:nθ∂r” and those detected data and voice data are stored as registered voice data in the unit designation voice data memory table  19   b  in association with each other. 
     In other words, in unit designation voice registration mode, voice data corresponding to the voice uttered by the user is registered in the unit designation voice data memory table  19   b  in association with the name of the audio unit in operation, as shown in FIG.  3 B. 
     When the registration of voice data is completed, the flow advances to step  310  where, as in step  210 , a guidance sound of “Registered” is output from the speaker  5 , informing the user of the end of the registration. After the voice registration mode is completed, the operation goes again to the standby mode and starts the routine in FIG. 10 again at step  100 . 
     When it is determined in step  306  that speech recognition has not been done properly, the flow moves to step  312 . In step  312 , as in step  212 , the controller  21  checks the value of the program counter to determine if the check is the second time. If it is the second time, the flow goes to step  314 . 
     In step  314 , as in step  214 , a guidance sound of “Beep Beep” is reproduced from the speaker  5 , notifying registration failure. When the voice registration mode is ended, the operation comes again to the standby mode and starts the routine in FIG. 10 again at step  100 . That is, if the property of the uttered voice cannot be extracted accurately due to the influence of noise or the like, the user should perform the registering operation from the start. 
     When it is determined in step  312  that the value of the program counter is “1”, the flow goes to step  316 . In step  316 , as in step  216 , it is determined whether or not the voice registration has taken less than 2.5 seconds. When the voice registration has taken 2.5 seconds or longer, a guidance sound of “Beep . . . Too long” is reproduced from the speaker  5 , warning the user that the time for the voice registration is too long. If the voice registration mode has not been carried out properly due to some other factors, a guidance sound of “Beep . . . Try again” is reproduced from the speaker  5 , requesting the user to make voice input again. 
     When this notification is completed, “2” is set in the program counter and the operation restarts at step  300  to allow the user to utter desired words again. In other words, the step  316  mainly gives a warning to the effect that the way the user utters a voice by has not been adequate. When the user properly utters intended words again in response to this warning, the voice data is registered in step  308 . Therefore, the user can register adequate voice data without manipulating the unit registration/search key  9  again, thus leading to an improved operability. 
     Once the user continuously depresses the unit registration/search key  9  for 2 or more seconds, merely uttering words according to a guidance sound can cause the uttered words to be registered in the unit designation voice data memory table  19   b  in association with the name of the audio unit in operation. After this registering operation, the user has only to utter words corresponding to any registered voice data in order to ensure voice-based manipulation (whose details will be given later) for designating an audio unit. 
     A description will now be given of the operation in the case where it is determined in step  106  that the equalizer-adjustment voice registration/search key  10  has been continuously depressed for 2 or more seconds. When the depression of this key  10  continues for 2 or more seconds, the mode is set to the equalizer-adjustment voice registration mode and the operation goes to a routine shown in FIG.  13 . 
     First, the voice synthesizer  20  reproduces a guidance sound of “Register equalizer mode” in step  400 . In the next step  402 , the controller  21  restarts the program counter constructed by the system program to measure the time for one second. It is determined in steps  404  and  406  within this one second if the equalizer-adjustment voice registration/search key  10  has been depressed for a short time or any one of the other operation keys  6 - 9  and  11  has been depressed for a short time. 
     When it is the equalizer-adjustment voice registration/search key  10  that has been depressed for a short time, the flow goes to step  408 . When it is one of the other operation keys  6 - 9  and  11  that has been depressed for a short time, the flow goes to step  410 . When none of the operation keys  6 - 11  has been manipulated within one second, the flow goes to step  420 . 
     When it is determined in step  406  that a key other than the equalizer-adjustment voice registration/search key  10 , i.e., one of the other operation keys  6 - 9  and  11  has been depressed for a short time, and the flow goes to step  410 , a process corresponding to the depressed operation key is performed, and the flow returns to step  100  in FIG.  10 . 
     When it is determined in step  404  that the equalizer-adjustment voice registration/search key  10  has been depressed for a short time, and the flow goes to step  408 , the voice synthesizer  20  reproduces a guidance sound of “Register listening position” after which the flow moves to step  412 . In step  412 , the program timer is restarted to measure the time for one second. 
     In steps  414  and  416 , it is determined within this one second whether the equalizer-adjustment voice registration/search key  10  or one of the other operation keys  6 - 9  and  11  has been depressed for a short time. When the equalizer-adjustment voice registration/search key  10  has been depressed for a short time, the flow returns to step  400 . When one of the other operation keys  6 - 9  and  11  has been depressed for a short time, a process corresponding to the depressed key is performed, then the flow returns to step  100  in FIG.  10 . 
     In steps  402 - 418 , when the equalizer-adjustment voice registration/search key  10  is depressed once for a short time, the mode is set to a voice registration mode for setting the frequency characteristic of the equalizer as an audio unit, and when the second depression of the equalizer-adjustment voice registration/search key  10  is made within the first one second, the mode is set to a voice registration mode for setting each output level (listening position) of each channel of the stereo speaker, before the flow advances to step  420 . 
     When a key different from the equalizer-adjustment voice registration/search key  10 , i.e., one of the operation keys  6 - 9  and  11  is depressed for a short time within the first one second or within the next one second, a process corresponding to the depressed key is carried out. 
     In the subsequent step  420 , the voice synthesizer  20  reproduces a guidance sound of “Peep” to inform the user of the beginning of registration. In step  422 , the speech recognizer  18  performs speech recognition on the voice uttered by the user in accordance with that guidance sound. In this case, accurate speech recognition is executed by extracting the uttered voice based on the first and second threshold values THD 1  and THD 2 , as in the case illustrated in FIGS. 11 and 12. 
     Then, it is determined in step  424  if speech recognition has been carried out properly. When speech recognition has been performed adequately, the flow goes to step  426 . 
     In step  426 , the controller  21  detects the present setting state of the equalizer via the I/F circuit  22  and the interface port  23  and stores the detected data and the voice acquired by the speech recognition in the equalizer-adjustment voice data memory table  19   c  in association with each other (in combination). 
     When the operation goes to step  420  from step  402 , i.e., when the user has instructed the voice registration mode for setting the frequency characteristic of the equalizer and the user has adjusted the equalizer to “super bass” and utters words “super bass” (s(j)u:per baés), then the state of the “super bass” of the equalizer and the voice data of “super bass” are stored in the equalizer-adjustment voice data memory table  19   c.    
     When the operation goes to step  420  from step  412 , i.e., when the user has instructed the voice registration mode for setting the listening position and the user has adjusted the state of the speaker output to “front right” and utters a word “right” (rait), then the state of the “front right” and the voice data of “right” are stored in the equalizer-adjustment voice data memory table  19   c.    
     Then, in step  426 , a guidance sound of “Registered” is reproduced from the speaker  5 , notifying the user of the end of the registration. After the voice registration mode is completed, the operation goes again to the standby mode and starts the routine in FIG. 10 again at step  100 . 
     When it is determined in step  424  that speech recognition has not been done properly, the flow moves to step  428 , but when it is the second time, the flow goes to step  430 , as done in step  212  in FIG.  11 . 
     In step  430 , as in step  214 , a guidance sound of “Beep Beep” is reproduced from the speaker  5 , notifying registration failure. When the voice registration mode is ended, the operation comes again to the standby mode and starts the routine in FIG. 10 again at step  100 . That is, if the property of the uttered voice cannot be extracted accurately due to the influence of noise or the like, the user should perform the registering operation from the start. 
     When it is determined in step  428  that the value of the program counter is “1”, the flow goes to step  432  where, as in step  216 , it is determined whether or not the voice registration has taken less than 2.5 seconds. When the voice registration has taken 2.5 seconds or longer, a guidance sound of “Beep . . . Too long” is reproduced from the speaker  5 , warning the user that the time for the voice registration is too long. If the voice registration mode has not been carried out properly due to some other factors, a guidance sound of “Beep . . . Try again” is reproduced from the speaker  5 , requesting the user to make voice input again. 
     When this notification is completed, the operation restarts at step  420  to allow the user to utter desired words again. Therefore, the user can register adequate voice data without manipulating the equalizer-adjustment voice registration/search key  10  again. This results in an improvement of the operability. Once the user depresses the equalizer-adjustment voice registration/search key  10 , merely uttering words according to a guidance sound can cause the uttered words to be registered in the equalizer-adjustment voice data memory table  19   c  in association with the current adjustment state of the equalizer. After this registering operation, the user has only to utter words corresponding to any registered voice data in order to ensure voice-based manipulation (whose details will be given later) for adjusting the equalizer. 
     A description will now be given of the operation in the case where it is determined in step  108  in FIG. 10 that the volume control/guidance language switching key  11  has been continuously depressed for 2 or more seconds. When the depression of this key  11  continues for 2 or more seconds, the mode is set to the language switching mode and the controller  21  changes the voice guidance data stored in the guidance data memory table  19   d  and performs some setting to turn off the generation of a guidance sound, as shown in FIG.  7 A. The guidance data memory table  19   d  prestores voice guidance data in plural countries, such as English, German and French, in addition to voice guidance data in Japanese. Every time the volume control/guidance language switching key  11  is depressed for 2 or more seconds, the controller  21  sequentially controls the changing of the voice guidance data in each country and the disabling of the generation of a guidance sound. Therefore, the user can set the language of guidance voices to a desired country&#39;s language and set off guidance voices by operating the volume control/guidance language switching key  11 . 
     A description will now be given of the operation in the case where it is determined in step  110  in FIG. 10 that the volume control/guidance language switching key  11  has been depressed for a short time. When the depression of this key  11  continues for a short time, the mode is set to the volume control mode and the controller  21  sequentially switches the amplification factor of the speaker amplifier  16  within the range of three levels of high, middle and low as shown in FIG.  7 B. Therefore, the user can adjust the output volume of the speaker  5  to one of the high volume, middle volume and low volume by operating the key  11 . 
     A description will now be given of the operation in the case where it is determined in step  112  in FIG. 10 that the normal registration/voice-based operation key  6  has been for a short time. 
     When the normal registration/voice-based operation key  6  is depressed for a short time, the mode is set to the voice-based manipulation mode and the operation goes to a routine shown in FIG.  14 . In FIG. 14, first, the controller  21  sets “1” in the program counter and performs a sequence of processes starting at step  450 . 
     In step  450 , the voice synthesizer  20  reads predetermined voice guidance data from the guidance data memory table  19   d  and the imitation sound generator  17  generates an imitation sound signal of “Peep”. 
     The controller  21  sends those guidance voice signal and imitation sound signal to the speaker amplifier  16  and reproduces a guidance sound of “Please make request . . . Peep”, which consists of the guidance voice and imitation sound, from the speaker  5 , thus requesting the user to utter a voice for voice-based manipulation. 
     In the next step  452 , the speech recognizer  18  starts the speech recognition process. When the user utters an intended voice (words) corresponding to any of the voice data that are stored in the title designation voice data memory table  19   a , the unit designation voice data memory table  19   b  and the equalizer-adjustment voice data memory table  19   c , the speech recognizer  18  detects the beginning of the voice generation, at which point the program timer in the controller  21  is activated so that the speech recognizer  18  is controlled to execute speech recognition of the voice uttered within 2.5 seconds. In this case, accurate speech recognition is carried out by extracting the uttered voice based on the first and second threshold values THD 1  and THD 2 , which are higher than the level of ambient noise, as in the case of the above-described voice registration mode. 
     In the next step  454 , it is determined whether or not speech recognition has been completed. Then, it is determined if speech recognition has been performed properly in step  456 . This decision is made by checking if the level of the uttered voice (voice power) input as a recognition target has been higher than the first and second threshold values THD 1  and THD 2 . When it is determined that speech recognition has been done properly, the flow goes to step  458 . 
     In step  458 , the voice synthesizer  20  reads predetermined voice guidance data from the guidance data memory table  19   d  and the controller  21  sends this guidance voice signal to the speaker amplifier  16  to output a guidance sound of “OK” from the speaker  5 , thus giving acknowledgement information to the user. Further, the controller  21  searches the registered voice data in the title designation voice data memory table  19   a  based on the voice data acquired through the speech recognition and acquires information about an audio unit corresponding to that voice data (the aforementioned registered, received data). Then, the controller  21  generates a control signal based on the acquired information, and sends the control signal via the I/F circuit  22  and the interface port  23  to the audio unit specified by the user, thereby activating the audio unit. Then, the voice-based manipulation mode is ended and the operation comes to the standby mode to start the routine in FIG. 10 again at step  100 . 
     If the user utters a word “one” in step  452 , the title designation voice data memory table  19   a  shown in FIG. 3A is searched for information of “disc 1  track 1 ”. Then, the controller  21  controls the CD player corresponding to this information based on the control signal to reproduce a musical piece or the like on the track  1  of the recording/reproducing medium. 
     If the user utters a word “seven” in step  452 , the title designation voice data memory table  19   a  is searched for information of “band fml 76.1 MHz”. Then, the controller  21  controls the radio receiver corresponding to this information based on the control signal to tune itself to the broadcasting station of 76.1 MHz. 
     If the user utters an intended voice (words) corresponding to any of the voice data stored in the shown in FIG.  3 B and the equalizer-adjustment voice data memory table  19   c  shown in FIG. 3C, it is possible to perform a voice-based manipulation, such as activation of an associated audio unit or adjustment of the equalizer. 
     When it is determined in step  456  that speech recognition has not been done properly, the flow moves to step  460 . In step  460 , the controller  21  checks the value of the program counter to determine if the check is the second time. If it is the second time, the flow goes to step  462 . 
     In step  462 , the imitation sound generator  17  generates an imitation sound signal of “Beep Beep”. The controller  21  sends this imitation sound signal of “Beep Beep” to the speaker amplifier  16  and then outputs a guidance sound of “Beep Beep” from the speaker  5 , notifying registration failure. When the voice registration mode is ended, the operation comes again to the standby mode and starts the routine in FIG. 10 again at step  100 . In other words, if the property of the uttered voice cannot be extracted accurately due to the influence of noise or the like, the user should perform the registering operation from the start. 
     When it is determined in step  460  that the value of the program counter is “1”, the flow goes to step  464 . Instep  464 , the measured value of the program timer is checked to determine whether or not the voice registration has taken 2.5 seconds or longer. 
     When the voice registration has taken 2.5 seconds or longer, the voice synthesizer  20  reads predetermined voice guidance data from the guidance data memory table  19   d  and generates a guidance voice signal, and the imitation sound generator  17  generates an imitation sound signal of “Beep”. Then, the controller  21  supplies those guidance voice signal and imitation sound signal to the speaker amplifier  16  and reproduces “Beep . . . Too long” from the speaker  5 , warning the user that the time for the voice registration is too long. 
     If the voice registration mode has not been carried out properly due to some other factors, the voice synthesizer  20  reads predetermined voice guidance data from the guidance data memory table  19   d  and generates a guidance voice signal, and the imitation sound generator  17  generates an imitation sound signal of “Beep”. Then, the controller  21  supplies those guidance voice signal and imitation sound signal to the speaker amplifier  16  and reproduces “Beep . . . Try again” from the speaker  5 , requesting the user to make voice input again. 
     When this notification in step  464  is completed, “2” is set in the program counter and the operation restarts at step  450  to allow the user to utter desired words again. In other words, when the way the user utters a voice by has not been adequate, the user can perform a voice-based manipulation merely by uttering proper words, without manipulating the normal registration/voice-based operation key  6  again, as done in the voice registration mode. 
     Once the user continuously depresses the normal registration/voice-based operation key  6  for a short time, the user can manipulate a desired audio unit simply by uttering a voice (words) registered in any of the voice data memory tables  19   a - 19   c  in accordance with a guidance sound. 
     A description will now be given of the operation in the case where it is determined in step  114  in FIG. 10 that the search key  7  or  8  has been depressed for a short time. When a short depression of the key  7  or  8  occurs, the mode is set to the registered voice data search mode and the operation goes to a routine shown in FIGS. 15A and 15B. 
     In step  500 , the controller  21  searches the title designation voice data memory table  19   a  to determine if there is registered voice data. When there is no registered voice data (“NO”), a guidance sound of “No voice registered” is given and then, the flow returns to step  100  in FIG.  10 . 
     When there is registered voice data in step  500  (“YES”), however, the flow goes to step  502  to check a currently active audio unit and determine if registered voice data associated with that audio unit is present in the title designation voice data memory table  19   a  shown in FIG.  3 A. When the currently active audio unit is the radio tuner which is receiving radio waves from the broadcasting station of 81.1 MHz, for example, it is determined whether or not there is registered voice data corresponding to the broadcasting station of 81.1 MHz. 
     Assuming that there is voice data of a word “eight” (eit) corresponding to the broadcasting station of 81.1 MHz as shown in FIG. 3A, then, the voice synthesizer  20  reads the voice data of “eight” and performs voice synthesizing and outputs a synthesized voice of “eight” from the speaker  5 . 
     If there is no registered voice data associated with a currently active audio unit in step  502  (“NO”), the flow goes to step  506 . 
     In the case where the search/forward scan key  7  has been depressed for a short time, the voice data associated with an active audio unit registered in the title designation voice data memory table  19   a  is read in the forward sort direction and is converted into synthesized voices, which are output from the speaker  5  one after another in step  506 . In the case where the search/reverse scan key  8  has been depressed for a short time, the registered voice data associated with an active audio unit is read in the reverse sort direction and is converted into synthesized voices, which are output from the speaker  5  one after another. 
     Accordingly, the user can confirm voice data registered in the title designation voice data memory table  19   a  and can recheck the voice data even if the user has forgotten it. 
     In the next step  508 , the controller  21  measures the time of 8 seconds by means of the program timer. In steps  510 - 518 , the controller  21  determines if any of the other operational button switches  6 - 11  has been depressed for a short time within 8 seconds. When such a short key depression is detected, the controller  21  performs a process corresponding to the depressed key and then returns to step  100  in FIG.  10 . When none of the operational button switches  6 - 11  has been depressed for a short time even after passing of 8 seconds, the operation directly returns to step  100  in FIG. 10 from step  508 . 
     With the search/reverse scan key  8  depressed for a short time, when the search/forward scan key  7  is depressed for a short time in step  510 , the flow goes to step  520 . In step  520 , voice data stored at a memory address apart by one address from the address of the last voice data produced as a synthesized voice in the forward sort direction is read out and is produced as a synthesized voice. Then, the flow returns to step  508 . 
     With the search/forward scan key  7  depressed for a short time, when the search/reverse scan key  8  is depressed for a short time in step  512 , the flow goes to step  522 . In step  522 , voice data stored at a memory address apart by one address from the address of the last voice data produced as a synthesized voice in the reverse sort direction is read out and is produced as a synthesized voice. Then, the flow returns to step  508 . 
     That is, the order of presenting voice data registered in the title designation voice data memory table  19   a  is switched from one to the other in steps  520  and  522 . 
     When the unit registration/search key  9  is depressed for a short time in step  514 , the flow goes to step  524 . In step  524 , the unit designation voice data memory table  19   b  shown in FIG. 3B is searched to check if there is voice data corresponding to a currently active audio unit. If there is such voice data, this voice data is produced as a synthesized voice. When the currently active audio unit is the radio tuner, for example, a synthesized sound of a word “tuner” (t(j)u:nθ∂r) is produced. Then, the flow returns to step  508 . When there is no corresponding voice data, the top voice data in the unit designation voice data memory table  19   b  is read out and then the flow returns to step  508 . 
     When the equalizer-adjustment voice registration/search key  10  is depressed for a short time in step  516 , the flow goes to step  526 . In step  526 , the equalizer-adjustment voice data memory table  19   c  shown in FIG. 3C is searched to check if there is registered voice data associated with the equalizer. If there is such voice data, this voice data is produced as a synthesized voice. Then, the flow returns to step  508 . When there is no corresponding voice data, the top voice data in the equalizer-adjustment voice data memory table  19   c  is read out and then the flow returns to step  508 . 
     When any of the other keys,  6  or  10 , is depressed in step  518 , the flow goes to step  528  to perform a process corresponding to each depressed key  6  or  10 . Then, the flow moves to step  508 . 
     Because the user can confirm voice data registered in the title designation voice data memory table  19   a , the unit designation voice data memory table  19   b  and the equalizer-adjustment voice data memory table  19   c  by depressing any of the operational button switches  7 ,  8 ,  9  and  10  to set the registered voice data search mode, as apparent from the above, the user can check voice data again even if he or she has forgotten it. 
     A description will now be given of the operation in the case where it is determined in step  116  in FIG. 10 that the search/forward scan key  7  or the search/reverse scan key  8  has been continuously depressed for 2 or more seconds. When the depression of this key  7  or  8  continues for 2 or more seconds, the mode is set to the registered voice data scan mode and the processes illustrated in FIG. 8B or FIG. 9B are performed. When the search/forward scan key  7  has been continuously depressed for 2 or more seconds, voice data already registered in the title designation voice data memory table  19   a  shown in FIG. 3A is read (scanned) in the forward sort direction and is sequentially produced as synthesized voices. If the normal registration/voice-based operation key  6  is depressed during the action, an audio unit corresponding to the last searched or scanned voice data is controlled based on this voice data. 
     When the search/reverse scan key  8  has been continuously depressed for 2 or more seconds, voice data already registered in the title designation voice data memory table  19   a  shown in FIG. 3A is read (scanned) in the reverse sort direction and is sequentially produced as synthesized voices. If the normal registration/voice-based operation key  6  is depressed during the action, the currently active audio unit corresponding to the last searched or scanned voice data is controlled based on this voice data. 
     A description will now be given of the operation in the case where it is determined in step  118  in FIG. 10 that the unit registration/search key  9  has been depressed for a short time. When the short depression of this key  9  occurs, the mode is set to the unit designation voice data search mode and the process shown in FIG. 5B is executed. Specifically, voice data associated with the name of the currently active audio unit, which is already registered in the unit designation voice data memory table  19   b , is produced as a synthesized voice. When voice data associated with the name of the currently active audio unit is not registered, the mode is switched to the unit designation voice data scan mode for sequentially producing voice data associated with the names of other audio units as synthesized voices. When the unit registration/search key  9  is depressed again during the unit designation voice data scan mode, the mode is switched to the one that produces the voice data, which is associated with the name of the currently active audio unit and is already registered in the unit designation voice data memory table  19   b , as a synthesized voice. When the normal registration/voice-based operation key  6  is depressed during the unit designation voice data search mode or the unit designation voice data scan mode, the currently active audio unit corresponding to the last searched or scanned voice data is controlled based on this voice data. 
     A description will now be given of the operation in the case where it is determined in step  120  in FIG. 10 that the equalizer-adjustment voice registration/search key  10  has been depressed for a short time. When a short depression of this key  10  occurs, the mode is set to the equalizer-adjustment voice data search mode and the processes shown in FIG. 6C are executed. Specifically, voice data which is associated with the currently set positioning state or the current frequency characteristic of the equalizer and is registered in the equalizer-adjustment voice data memory table  19   c  shown in FIG. 3C is produced as a synthesized voice. When the equalizer-adjustment voice registration/search key  10  is depressed during the equalizer-adjustment voice data search mode, all the pieces of voice data registered in the equalizer-adjustment voice data memory table  19   c  is scanned and are sequentially produced as synthesized voices. If the normal registration/voice-based operation key  6  is depressed during the action, the currently active audio unit corresponding to the last searched or scanned voice data is controlled based on this voice data. 
     To perform a voice-based manipulation, as apparent from the foregoing description, the voice-based manipulation apparatus of this embodiment searches or scans the voice data registered in the title designation voice data memory table  19   a , the unit designation voice data memory table  19   b  and the equalizer-adjustment voice data memory table  19   c  and produces the searched or scanned voice data as a synthesized voice. Even if the user does not remember registered voice data, the user can easily check the correlation between registered voices and their corresponding manipulation targets. Unlike the prior art, therefore, it is unnecessary to register voice data again from the beginning, thus demonstrating an excellent operability. 
     As a plurality of operational functions are assigned to each of the operational button switches  6 - 11 , it is possible to reduce the number of required operational button switches, which can contribute to designing the remote operation section  4  more compact. 
     Although the foregoing description of this invention has been given of the embodiment which is designed to perform voice-based manipulation of an audio system, this invention is not limited to a voice-based manipulation apparatus for audio systems. For example, this invention may be adapted to an on-board unit for a vehicle which has an air-conditioning system equipped in addition to an on-board audio system, so that those audio system and air-conditioning system can be manipulated by voices. Further, this invention is not limited to an audio system, but may be adapted to manipulate various other manipulation targets with voices. 
     In short, the voice-based manipulation apparatus according to this invention has a search section which searches voice information stored in a storage section in association with a manipulation target and produces the searched voice information. Even if a user has forgotten any registered voice information, for example, this apparatus can provide the user with the correlation between the voice information and the associated manipulation target. This makes it unnecessary for the user to store the voice information again in the storage section due to a memory problem or the like and provides the user an excellent operability.