Information processing apparatus, information processing method, and computer program product

According to one embodiment, an information processing apparatus includes one or more processors configured to detect a trigger from a voice signal, the trigger indicating start of voice recognition; and to perform voice recognition of a recognition sound section subsequent to a trigger sound section including the detected trigger, referring to a trigger and voice recognition dictionary corresponding to the trigger.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2018-134664, filed on Jul. 18, 2018; the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to an information processing apparatus, an information processing method, and a computer program product.

BACKGROUND

speech recognition systems have been put to practical use, which recognize user's spoken commands to operate devices. Such a system detects speech of a certain keyword as a trigger for starting speech recognition and performs speech recognition to voice after the trigger.

In the case of continuous speech, however, it may be unable to detect a trigger and perform speech recognition after the trigger.

It is preferable to provide an information processing apparatus, an information processing method, and an information processing program that enable improvement in speech recognition.

DETAILED DESCRIPTION

According to one embodiment, generally, an information processing apparatus includes one or more processors configured to detect a trigger from a voice signal, the trigger indicating start of speech recognition; and to perform speech recognition of a recognition sound section subsequent to a trigger sound section including the detected trigger, referring to a trigger and speech recognition dictionary corresponding to the trigger.

Exemplary embodiment of an information processing apparatus, an information processing method, and a computer program product will be described in detail below with reference to the accompanying drawings.

FIG. 1is an exemplary functional block diagram of an information processing apparatus10according to the present embodiment. The information processing apparatus10recognizes voice from voice signals.

The information processing apparatus10includes a controller12, a receiver15, an output17, an input22, a audio data storage24, and a storage26. The controller12, the receiver15, the output17, the input22, the audio data storage24, and the storage26are connected to one another to be able to transmit and receive data and signals.

The receiver15receives a voice signal. A voice signal refers to a signal representing voice. The voice signal is represented by a time-series set of sound signals. A sound signal refers to a signal representing sound collected at certain timing. Specifically, a voice signal is represented by a time-series set of sound signals collected at each timing.

The present embodiment illustrates the voice signal representing voice uttered by the user, as an example. The voice signal may include sound generated from an object, such as a machine. As another example, the voice signal may include both voice uttered by the user and sound generated from an object.

The receiver15includes at least one of a microphone14and a communicator16. The microphone14collects voice, converts the voice into an electrical signal, and outputs the signal as a voice signal to the controller12. The communicator16communicates with external devices through a network in a wired or wireless manner. When the communicator16functions as the receiver15, the communicator16receives a voice signal of voice stored in or collected by an external device, from the external device.

The output17outputs various kinds of information. In the present embodiment, the output17outputs a result of speech recognition by the controller12, as described in detail later.

The output17includes at least one of the communicator16, a display18, and a speaker20. When the communicator16functions as the output17, the communicator16transmits a result of speech recognition to the external device through a network, for example. The display18displays information representing a result of speech recognition. The display18represents a known liquid crystal display or organic electroluminescence (EL) display. The display18may be a touch panel integrally including both an input function and a display function.

The input22receives operation inputs from the user. The input22represents a keyboard, a mouse, and/or a pointing device.

At least one of the microphone14, the display18, the speaker20, and the input22may be separately provided from the information processing apparatus10. For example, at least one of the microphone14, the display18, the speaker20, and the input22may be communicably connected to the information processing apparatus10in wired or wireless manner through the network. As another example, the microphone14or the display18may be incorporated in a terminal device connected with the information processing apparatus10through the network, for example.

The audio data storage24stores various types of data. The audio data storage24represents a known storage medium. In this embodiment, the audio data storage24functions as a buffer that stores therein voice signals received by the receiver15. The capacity of the audio data storage24may be arbitrary as long as it can store a voice signal of a length exceeding the length of the trigger sound section of the trigger contained in the voice signal. Herein, trigger refers to a command and/or a signal triggering any operation. The trigger and the trigger sound section will be described in detail later.

The storage26stores various types of data. The storage26represents a known storage medium. In the present embodiment, the storage26stores a trigger dictionary26A, a trigger and speech recognition dictionary26B, and a speech recognition dictionary26C in advance.

FIG. 2Ais a schematic diagram illustrating an exemplary data configuration of the trigger dictionary26A. The trigger dictionary26A represents a dictionary in which one or two or more triggers are registered in advance. The trigger refers to voice serving as a keyword that triggers speech recognition. The trigger may be a word (trigger word) representing a trigger, or a volume change pattern indicating a trigger. The present embodiment illustrates a trigger word as an example of the trigger. The trigger may indicate a command to an electronic device in addition to the start of speech recognition.

The storage26has a plurality of predetermined triggers registered in the trigger dictionary26A. The triggers registered in the trigger dictionary26A may be properly changeable in accordance with a user's operation to the input22.

FIG. 2Aillustrates “model number” and “please” as exemplary triggers. The triggers are not limited thereto.

The triggers may be spoken in stepwise manner. For example, the user may speak a trigger word representing an approximate instruction, and then speak trigger words representing a detailed instruction in stepwise manner. For this reason, the storage26may store a plurality of trigger dictionaries26A hierarchically in the order of utterance of the triggers.

FIG. 2Bis a schematic diagram illustrating an exemplary data configuration of trigger dictionaries26A. The storage26registers triggers representing approximate instructions to an electronic device in a trigger dictionary26A1, for example. The storage26stores therein trigger dictionaries26A2(26A2aand26A2b) in which triggers to be spoken next representing instructions more detailed by one level are registered, in association with the triggers registered in the trigger dictionary26A1. In addition, the storage26stores therein trigger dictionaries26A3in which triggers to be spoken next representing instructions more detailed by one more level are registered, in association with the triggers registered in the trigger dictionaries26A2.

Thus, the storage26may store the trigger dictionaries26A in a hierarchical manner.

Returning toFIG. 1, the trigger and speech recognition dictionary26B and the speech recognition dictionary26C are described next.

The storage26stores therein in advance the trigger and speech recognition dictionary26B and the speech recognition dictionary26C for each of the triggers. In the present embodiment, the storage26stores therein in advance the trigger and speech recognition dictionary26B and the speech recognition dictionary26C for each of the triggers registered in the trigger dictionary26A.

For example, the storage26stores the trigger and voice speech recognition dictionaries26B and the voice speech recognition dictionaries26C in advance, in association with triggers ID for identifying the triggers registered in the trigger dictionary26A.

The trigger and voice speech recognition dictionary26B is a dictionary for deriving a result of voice speech recognition of a recognition sound section from a trigger sound section and a recognition sound section.

Specifically, the trigger and voice speech recognition dictionary26B represents grammar data that defines the grammar to be used for voice speech recognition. The trigger and voice speech recognition dictionary26B is a dictionary to which the trigger sound section and the recognition sound section are input as input data. That is, the trigger sound section and the recognition sound section are input to the trigger and voice speech recognition dictionary26B as input data, which allows voice speech recognition of the trigger sound section and the recognition sound section contained in the input data, to acquire a result of voice speech recognition of the recognition sound section.

The voice speech recognition dictionary26C is a dictionary for deriving a result of voice speech recognition of a sound section from the sound section. The term “sound section” refers to a section containing voice in a voice signal. The expression “containing voice” signifies containing sound of volume equal to or larger than a preset threshold. The threshold may be any volume value to distinguish between no sound and sound, and may be preset. That is, the sound section is represented by a time-series set of sound signals indicating sound.

The voice speech recognition dictionary26C represents grammar data that defines the grammar to be used for voice speech recognition. The voice speech recognition dictionary26C refers to a dictionary to which the sound sections are input as input data. That is, a sound section is input to the voice speech recognition dictionary26C as input data, which allows voice speech recognition of the sound section referring to the voice speech recognition dictionary26C, to acquire a result of the voice speech recognition of the sound section.

In the present embodiment, the trigger and voice speech recognition dictionary26B and the voice speech recognition dictionary26C are prepared for each of the triggers registered in the trigger dictionary26A, and stored in advance in the storage26in association with the triggers ID of the triggers. Thus, the storage26stores the trigger and voice speech recognition dictionary26B and the voice speech recognition dictionary26C therein in advance for each of the triggers registered in the trigger dictionary26A.

The voice audio data storage24and the storage26may be integrated as one storage. As another example, at least part of data stored in the storage26may be stored in an external device, such as an external server.

The controller12will be described next. The controller12controls the information processing apparatus10. The controller12includes a voice acquirer12A, a detector12B, a voice speech recognizer12C, an output controller12D, and a receiver12E.

The voice acquirer12A, the detector12B, the voice speech recognizer12C, the output controller12D, and the receiver12E can be implemented by, for example, one or two or more processors. For example, each of the elements described above may be implemented by software, i.e., by causing a processor such as a central processing unit (CPU) to execute a program. The elements may be implemented by hardware, e.g., a processor such as a dedicated integrated circuit (IC). The elements may be implemented by both software and hardware. In the case of using a plurality of processors, each of the processors may implement one or two or more of the elements.

The voice acquirer12A acquires a voice signal. In the present embodiment, the voice acquirer12A acquires a voice signal from the microphone14or the communicator16. The voice acquirer12A stores the acquired voice signal in the voice audio data storage24.

As described above, the voice audio data storage24has the capacity to store a voice signal of a length exceeding the length of a trigger sound section, and a voice signal is a time-series set of sound signals. For this reason, when the voice audio data storage24becomes full in capacity, the voice acquirer12A deletes the sound signals from the voice signal in the voice audio data storage24in order from the most previous sound signal, and overwrites the signal with a new sound signal for storage. Thus, the voice audio data storage24stores the latest voice signal.

The detector12B detects a trigger for starting voice speech recognition from the voice signal. The detector12B reads the voice signal from the voice audio data storage24in time series, and detect the trigger by identifying a time-series set of sound signals matching any of the triggers registered in the trigger dictionary26A. The detector12B may detect triggers by any known method. For example, the detector12B may detect a trigger by reading the voice signal from the head in time-series, comparing the voice signal with a signal being a time-series set of sound signals converted from each of the triggers stored in the trigger dictionary26A and determining whether there is any section matching the converted signal.

As described above, the voice audio data storage24may store multiple trigger dictionaries26A in a hierarchical manner. In this case, the detector12B preferably reads the voice signal in time series, and, upon each detection of a trigger, uses the trigger dictionary26A (for example, the trigger dictionary26A2) of a lower level corresponding to the detected trigger for detection of the next trigger. Thus, the detector12B reads the hierarchically stored trigger dictionaries26A in order from the upper level to the lower level for the next trigger detection, thereby reducing the number of trigger candidates to detect and improving the accuracy of trigger detection.

Upon detection of a trigger, the detector12B notifies the voice speech recognizer12C of the trigger ID of the detected trigger and head information representing the head of the trigger sound section of the trigger. The head of the trigger sound section refers to the most upstream end of the trigger sound section in time series. The head information of the trigger sound section may be any information as long as it represents the head of the trigger sound section. The head information is, for example, represented by start time indicating the head of the trigger sound section. In the following, the head and the head information may be referred to as start time.

The voice speech recognizer12C recognizes voice from the recognition sound section subsequent to the trigger sound section of the detected trigger in the voice signal, referring to the trigger and voice speech recognition dictionary26B corresponding to the trigger detected by the detector12B. In other words, the voice speech recognizer12C performs voice speech recognition of the trigger sound section of the detected trigger and the recognition sound section subsequent to the trigger sound section in accordance with the trigger and voice speech recognition dictionary26B corresponding to the trigger in the trigger sound section, to acquire a result of the voice speech recognition of the recognition sound section. In the present embodiment, the detector12B and the voice speech recognizer12C execute the detection and the voice speech recognition in parallel.

More specifically, the voice speech recognizer12C reads voice signals from the voice audio data storage24in chronological order, in parallel with reading and detection of the voice signals by the detector12B. When receiving the trigger ID and the head information of the trigger sound section from the detector12B, the voice speech recognizer12C determines detection of a trigger. The voice speech recognizer12C reads, from the storage26, the trigger and voice speech recognition dictionary26B corresponding to the trigger ID received from the detector12B.

The voice speech recognizer12C performs voice speech recognition of the recognition sound section subsequent to the trigger sound section in a unitary section, referring to the read trigger and voice speech recognition dictionary26B. The unitary section ranges from the head of the trigger sound section of the detected trigger to a predetermined end after the trigger sound section in the voice signal.

The unitary section serves as unit of voice speech recognition by the voice speech recognizer12C, referring to the trigger and voice speech recognition dictionary26B. In other words, the unitary section refers to the unit of section of a voice signal40to be input to the voice speech recognition dictionary26C when the voice speech recognizer12C performs voice speech recognition referring to the trigger and voice speech recognition dictionary26B. The end of the unitary section may be arbitrarily set after the trigger sound section of the detected trigger.

FIG. 3is an explanatory drawing illustrating an exemplary trigger detection and voice speech recognition. Suppose that the voice acquirer12A acquire the voice signal40representing “model number AA, voltage 20 V” from speech of a user U, by way of example. In addition, suppose that the words “model number” and “voltage” in the voice signal40be trigger words representing triggers, and that these triggers be registered in advance in the trigger dictionary26A.

The detector12B reads the voice signal40from the head in chronological order for trigger detection (see arrow A1). The detector12B detects the trigger “model number” from a trigger sound section T1including the trigger “model number” in the voice signal40. The trigger sound section T1is an exemplary trigger sound section T. The detector12B notifies the voice speech recognizer12C of the trigger ID of the detected trigger “model number” and the start time t1of the trigger sound section T1.

Upon receiving the trigger ID of the detected trigger “model number” and the start time t1of the trigger sound section T1from the detector12B, the voice speech recognizer12C reads a unitary section B1ranging from the start time t1of the trigger sound section T1to the end after the trigger sound section T1from the voice signal40. The unitary section B1is an exemplary unitary section B. The voice speech recognizer12C performs voice speech recognition of the unitary section B1including the trigger sound section T1, referring to the trigger and voice speech recognition dictionary26B corresponding to the trigger ID of the trigger “model number”, to output a result of the voice speech recognition of a recognition sound section S1of the unitary section B1. The recognition sound section S1is an exemplary recognition sound section S subsequent to the trigger sound section T1in the unitary section B1.

Meanwhile, the detector12B reads and detects the voice signal40in parallel (see arrow A2). The detector12B reads and detects the trigger “voltage” from a trigger sound section T2containing the trigger “voltage”. The detector12B notifies the voice speech recognizer12C of the trigger ID of the detected trigger “voltage” and the start time t3of a trigger sound section T2. The trigger sound section T2is an exemplary trigger sound section T. In addition, the detector12B continues reading and detecting the voice signal40(see arrow A3).

Upon receiving the trigger ID of the detected trigger “voltage” and the start time t3of the trigger sound section T2from the detector12B, the voice speech recognizer12C reads a unitary section B2ranging from the start time t3of the trigger sound section T2to the end after the trigger sound section T2in the voice signal40. The unitary section B2is an exemplary unitary section B. The voice speech recognizer12C performs voice speech recognition of the unitary section B2, referring to the trigger and voice speech recognition dictionary26B corresponding to the trigger ID of the trigger “voltage”, to output a result of the voice speech recognition of a recognition sound section S2in the unitary section B2. The recognition sound section S2is an exemplary recognition sound section S subsequent to the trigger sound section T2in the unitary section B2.

Thus, the voice speech recognizer12C uses not only the recognition sound section S of interest but also the unitary section B including both the trigger sound section T and the recognition sound section S as input data to the trigger and voice speech recognition dictionary26B corresponding to the trigger, to output a result of the voice speech recognition of the recognition sound section S in accordance with the trigger and voice speech recognition dictionary26B.

As described above, the unitary section B may be an arbitrary section as long as it ranges from the head of the trigger sound section T of the detected trigger to a predetermined end after the trigger sound section T in the voice signal40.

For example, the unitary section B has a predetermined length starting from the head of the trigger sound section T of the detected trigger and exceeding the length of the trigger sound section T. As another example, the unitary section B ranges from the head of the trigger sound section T of the detected trigger to a head of another trigger sound section T following the trigger sound section T. As another example, the unitary section B ranges from the head of the trigger sound section T of the detected trigger to a silence section following the trigger sound section T.

As illustrated inFIG. 4A, for example, the unitary section B has a predetermined length L starting from the head of the trigger sound section T of the detected trigger and exceeding the length of the trigger sound section T. In this case, the unitary section B1is a section having a length L starting from the start time t1of the trigger sound section T1containing the trigger “model number”. The unitary section B2has a length L starting from the start time t2of the trigger sound section T2. The length L may be preset to a length exceeding the length of the longest one of the trigger sound sections of the triggers registered in the trigger dictionary26A.

In the unitary section B having a predetermined length L from the head of the trigger sound section T of the detected trigger, the recognition sound section S (for example, recognition sound section S1) may include the trigger sound section T (for example, the trigger sound section T2) of the trigger to be detected next. In the present embodiment, the unitary section B may be any section as long as it includes a trigger sound section T at the head in time series, or the recognition sound section S subsequent to the trigger sound section T may include another trigger sound section T.

In this case, the voice speech recognizer12C can perform voice speech recognition of the unitary sections B having the same length L, each time the detector12B detects a trigger.

As illustrated inFIG. 4B, the unitary section B may range from the head of the trigger sound section T of the detected trigger to the head of another trigger sound section T following the trigger sound section T. In this case, the unitary section B1ranges from the start time t1of the trigger sound section T1to the start time t3of the subsequent trigger sound section T2. The unitary section B2ranges from the start time t3of the trigger sound section T2to the start time t4of the subsequent trigger sound section T3.

In the unitary section B ranging from the head of the trigger sound section T of the detected trigger to the head of another trigger sound section T following the trigger sound section T, the recognition sound section S (recognition sound section S1and recognition sound section S2) includes no other trigger sound sections T.

In this case, the voice speech recognizer12C can perform voice speech recognition of the recognition sound section S following each trigger and including no other triggers. That is, the voice speech recognizer12C can perform voice speech recognition of the recognition sound section S continuously following the trigger in unit of trigger.

The unitary section B may range from the head of the trigger sound section T of the detected trigger to the end of another trigger sound section T following the trigger sound section T. In this case, the recognition sound section S of the unitary section B includes another trigger sound section T.

As illustrated inFIG. 4C, the unitary section B may range from the head of the trigger sound section T of the detected trigger to a silence section N following the trigger sound section T. In this case, as illustrated inFIG. 4C, the unitary section B1ranges from the start time t1of the trigger sound section T1to a silence section N1following the trigger sound section T1. The silence section N1is an exemplary silence section N. The end of the unitary section B1may be set to any time from the start time t2to the end time t3of the silence section N1. The unitary section B2may be any section ranging from the start time t3of the trigger sound section T2to a silence section N2following the trigger sound section T2. The silence section N2is an exemplary silence section N. The end of the unitary section B2may be set to any time from the start time to the end time of the silence section N2, as with the unitary section B1.

In this case, the voice speech recognizer12C can divide the voice signal40by each silence section N for voice speech recognition.

The voice speech recognizer12C may determine the silence section N in the voice signal40by a known method. The detector12B may also detect the silence section N from the voice signal40. In this case, the voice speech recognizer12C may determine the silence section N, upon receipt of information on the silence section N from the detector12B. As another example, the information processing apparatus10may include a known detector that identifies the silence section N from the voice signal40. In this case, the voice speech recognizer12C may acquire a result of identification of the silence section N from the detector to determine the silence section N.

Returning toFIG. 1, according to the present embodiment, the voice speech recognizer12C performs voice speech recognition of the trigger sound section T of the detected trigger and the recognition sound section S subsequent to the trigger sound section T in the voice signal40, in accordance with the trigger and voice speech recognition dictionary26B corresponding to the detected trigger, to acquire a result of the speech recognition of the recognition sound section S.

Because of this, the information processing apparatus10according to the present embodiment can execute voice speech recognition of all the triggers in the voice signal40without omitting the recognition sound section S subsequent to the trigger sound section T of each trigger. That is, the information processing apparatus10according to the present embodiment can perform voice speech recognition of the recognition sound sections S continuously following all the triggers in the voice signal40of speech of continuous words containing multiple triggers.

As described above, suppose that the unitary section B, serving as the unit of voice speech recognition by the voice speech recognizer12C referring to the trigger and voice speech recognition dictionary26B, range from the head of the trigger sound section T of the detected trigger to the silence section N following the trigger sound section T. Also, suppose that the voice signal40include, after the unitary section B, a sound section including no trigger sound section T at the head. In this case, the sound section is not subjected to voice speech recognition, referring to the trigger and voice speech recognition dictionary26B.

In view of this, the voice speech recognizer12C performs voice speech recognition, switching between the voice speech recognition dictionary26C and the trigger and voice speech recognition dictionary26B.

Specifically, the voice speech recognizer12C performs voice speech recognition of the recognition sound section S in the unitary section B ranging from the head of the trigger sound section T of the detected trigger to the silence section N following the trigger sound section T in the voice signal40, referring to the trigger and voice speech recognition dictionary26B corresponding to the detected trigger. The voice speech recognizer12C then performs voice speech recognition of the sound section subsequent to the silence section N in the voice signal40, referring to the voice speech recognition dictionary26C corresponding to the detected trigger.

FIG. 5illustrates an exemplary voice speech recognition, switching between the trigger and voice speech recognition dictionary26B and the voice speech recognition dictionary26C. As illustrated inFIG. 5, the detector12B reads and detects a trigger from the voice signal40from the head in chronological order (see arrow A1). The detector12B reads and detects the trigger “model number” from the trigger sound section T1containing the trigger “model number” in the voice signal40. The detector12B notifies the voice speech recognizer12C of the trigger ID of the detected trigger “model number” and the start time t1of the trigger sound section T1.

Upon receiving the trigger ID of the detected trigger “model number” and the start time t1of the trigger sound section T1from the detector12B, the voice speech recognizer12C reads the unitary section B1ranging from the start time t1of the trigger sound section T1to the silence section N1following the trigger sound section T1in the voice signal40. The voice speech recognizer12C performs voice speech recognition of the recognition sound section S1in the unitary section B1, referring to the trigger and voice speech recognition dictionary26B corresponding to the trigger ID.

The voice speech recognizer12C performs voice speech recognition of a sound section V1following the silence section N1at the end of the unitary section B1, referring to the voice speech recognition dictionary26C corresponding to the previously detected trigger “model number”. The sound section V1is an exemplary voice section V between the silence section N1and a silence section N2.

The voice speech recognizer12C performs voice speech recognition of each of the sound sections V (V1and V2) subsequent to the unitary section B1, referring to the voice speech recognition dictionary26C corresponding to the previously detected trigger “model number”, until the detector12B detects a next trigger (trigger “voltage” in the example ofFIG. 5).

The voice speech recognizer12C may determine the detection of the next trigger by the detector12B, when receiving a new trigger ID and the start time of the trigger sound section T of the trigger identified by the trigger ID from the detector12B.

Specifically, the detector12B reads and detects the voice signal40in parallel (see arrow A2), and reads and detects the trigger “voltage” from the trigger sound section T2containing the next trigger “voltage”. The detector12B notifies the voice speech recognizer12C of the trigger ID of the detected trigger “voltage” and the start time t3of the trigger sound section T2. The detector12B continues reading and detecting the voice signal40(see arrow A3).

Upon receipt of the trigger ID of the new trigger “voltage” and the start time t3of the trigger sound section T2, the voice speech recognizer12C ends voice speech recognition of the sound section V based on the voice speech recognition dictionary26C corresponding to the trigger “model number”. The voice speech recognizer12C reads the unitary section B2ranging from the start time t3of the trigger sound section T2to the silence section N following the trigger sound section T2in the voice signal40. The voice speech recognizer12C may perform voice speech recognition of the recognition sound section S2in the unitary section B2, referring to the trigger and voice speech recognition dictionary26B corresponding to the trigger ID of the trigger “voltage”, in the same manner as above.

Thus, for the unitary section B ranging from the head of the trigger sound section T to the silence section N following the trigger sound section T, the voice speech recognizer12C performs voice speech recognition, switching between the trigger and voice speech recognition dictionary26B and the voice speech recognition dictionary26C to be referred to. Thereby, the voice speech recognizer12C can perform voice speech recognition, without omission, of the recognition sound sections S continuously following all the triggers in the voice signal40and the sound sections V non-continuously following the triggers.

Returning toFIG. 1, the output controller12D outputs the result of voice speech recognition of the voice speech recognizer12C to the output17. For example, the output controller12D transmits the result of voice speech recognition to an external device through the communicator16. As another example, the output controller12D displays the result of voice speech recognition on the display18. As another example, the output controller12D outputs the result of voice speech recognition by sound from the speaker20.

As described above, the voice speech recognizer12C derives a result of voice speech recognition of the recognition sound section S succeeding the trigger sound section T of each of the triggers contained in the voice signal40. That is, the voice speech recognizer12C derives multiple results of voice speech recognition.

As explained with reference toFIG. 4A, the voice speech recognizer12C may use a section of a predetermined length L starting from the head of the trigger sound section T of the detected trigger and exceeding the length of the trigger sound section T, as the unitary section B. In this case, the recognition sound section S in one unitary section B may include a trigger sound section T to be detected next and/or a recognition sound section S succeeding the trigger sound section T. Thus, the result of voice speech recognition derived for each of the triggers may include that of an overlapping section in the voice signal40.

In view of this, the output controller12D may remove a result of voice speech recognition of a section after the section concerned in the voice signal40from each of the results of voice speech recognition for output.

Specifically, as illustrated inFIG. 4A, the output controller12D may remove the results of voice speech recognition of the subsequent trigger sound section T2and the recognition sound section S2from the result of voice speech recognition of the recognition sound section S1to set the resultant as a result of voice speech recognition of the recognition sound section S1succeeding the trigger “model number”.

Returning toFIG. 1, the output controller12D may select one of the results of voice speech recognition, and output the selected result to the output17.

In this case, the receiver12E receives input of the selected result of voice speech recognition to output from the input22. For example, the output controller12D displays a list of the results of the voice speech recognition by the voice speech recognizer12C on the display18. The user operates the input22to select a result of voice speech recognition to output from the results of voice speech recognitions displayed on the display18. It is preferable that a user different from the speaker of the voice signal40select the result of voice speech recognition to output. Specifically, the user who selects the result of voice speech recognition to output is preferably an administrator of the information processing apparatus10.

When the receiver12E receives the input of the selected result of voice speech recognition to output from the input22, the output controller12D outputs, to the output17, the result of voice speech recognition received by the receiver12E among the results of voice speech recognition recognized by the voice speech recognizer12C.

When speaking, the user may speak an erroneous trigger word, for example, and then restate a correct trigger word. In such a case, the administrator issues an operation command through the input22to select a result of voice speech recognition to output, which enables the output controller12D to selectively output a proper result of voice speech recognition.

Next, an exemplary voice speech recognition by the information processing apparatus10according to the present embodiment is described.

FIG. 6is a flowchart illustrating an exemplary voice speech recognition procedure by the information processing apparatus10.FIG. 6illustrates an example that the voice acquirer12A sets a section ranging from the head of the trigger sound section T of the detected trigger to the silence section N following the trigger sound section T, as the unitary section B.

The voice acquirer12A acquires a voice signal40from the receiver15(Step S100), and stores the voice signal40in the voice audio data storage24(Step S102). Each time the receiver15receives a voice signal40, the voice acquirer12A continuously stores (overwrites) the voice audio data signal40in the voice audio data storage24.

Then, the detector12B starts reading the voice signal40from the voice audio data storage24in time series (Step S104). The detector12B repeats negative determination (No at Step S106) until detecting any of triggers registered in the trigger dictionary26A. Upon detecting a trigger (Yes at Step S106), the detector12B notifies the voice speech recognizer12C of the trigger ID of the detected trigger and the start time of the trigger sound section T.

Upon every detection of a new trigger by the detector12B, the speech recognizer12C repeats the processing from Step S110to Step S112.

Specifically, the voice speech recognizer12C acquires the trigger and voice speech recognition dictionary26B corresponding to the detected trigger from the storage26(Step S110). The voice speech recognizer12C reads and acquires the trigger and voice speech recognition dictionary26B, corresponding to the trigger ID previously received from the detector12B, from the storage26.

The voice speech recognizer12C performs voice speech recognition of the recognition sound section S in the unitary section B ranging from the start time of the previously received trigger sound section T from the detector12B to the silence section N following the trigger sound section T in the voice signal40, referring to the trigger and voice speech recognition dictionary26B acquired at Step S110(Step S112).

The output controller12D outputs the result of voice speech recognition of Step S112or Step S122to the output17(Step S114).

The voice speech recognizer12C determines whether a new trigger has been detected (Step S116). The voice speech recognizer12C makes the determination at Step S116by determining whether to have received a new trigger ID and the start time of the trigger sound section T from the detector12B.

When no new trigger is detected (No at Step S116), the voice speech recognizer12C proceeds to Step S118. At Step S118, the voice speech recognizer12C determines whether in the voice signal40, there is any sound section V subsequent to the unitary section B or the sound section V subjected to the previous voice speech recognition (Step S118).

With a negative determinations made at Step S118(No at Step S118), the voice speech recognizer12C returns to Step S116. When an affirmative determination at Step S118(Yes at Step S118), the voice speech recognizer12C proceeds to Step S120.

At Step S120, the voice speech recognizer12C acquires the voice speech recognition dictionary26C corresponding to the previously detected trigger from the storage26(Step S120).

The voice speech recognizer12C performs voice speech recognition of the sound section V identified at Step S118, referring to the voice speech recognition dictionary26C acquired at Step S120(Step S122). The voice speech recognizer12C then returns to Step S114.

With an affirmative determination made at Step S116(Yes at Step S116), the detector12B determines whether the trigger detected at Step S116is an end trigger indicating the end of the voice speech recognition (Step S124). With a negative determination made at Step S124(No at Step S124), the voice speech recognizer12C returns to Step S108. With an affirmative determination made at Step S124(Yes at Step S124), the voice speech recognizer12C proceeds to Step S126.

At Step S126, the output controller12D outputs the result of voice speech recognition to the output17(Step S126), completing the routine.

As described above, the information processing apparatus10according to the present embodiment includes the detector12B and the voice speech recognizer12C. The detector12B detects a trigger indicating start of voice speech recognition from the voice signal40. The voice speech recognizer12C performs voice speech recognition of the recognition sound section S subsequent to the trigger sound section T including the trigger, referring to the trigger and voice speech recognition dictionary26B corresponding to the detected trigger.

Thus, in the information processing apparatus10according to the present embodiment, the voice speech recognizer12C acquires a result of voice speech recognition of the recognition sound section S subsequent to the trigger sound section T of the detected trigger in the voice signal40through the voice speech recognition of the trigger sound section T and the recognition sound section S, in accordance with the trigger and voice speech recognition dictionary26B corresponding to the detected trigger. In addition, the trigger and voice speech recognition dictionary26B is intended for deriving a result of voice speech recognition of the recognition sound section S not only from the trigger sound section T but from the trigger sound section T and the recognition sound section S.

Thus, the information processing apparatus10according to the present embodiment can perform voice speech recognition, without omission, of the recognition sound sections S subsequent to the trigger sound sections T of all the triggers included in the voice signal40. That is, for continuous utterance of multiple words including multiple triggers, the information processing apparatus10according to the present embodiment can perform voice speech recognition of the recognition sound sections S continuously following all the triggers contained in the voice signal40of the utterance.

Conventionally, it is difficult to perform voice speech recognition of the voice signal40of the continuous utterance of multiple words including multiple triggers.

FIG. 7AandFIG. 7Bare explanatory drawings illustrating conventional voice speech recognition. Suppose that the user U speak, “please turn on the air conditioner, please temperature 28° C.” and a voice signal400of the speech be subjected to voice speech recognition, for example. Also, suppose that the word “please” in the voice signal400be a trigger.

As illustrated inFIG. 7A, for example, the triggers and the words other than the triggers are intermittently spoken. In this case, conventionally, the voice signal400is read from the head in chronological order. After the trigger “please” in the voice signal400is detected (see arrow A10), the words “turn on the air conditioner” following the trigger are recognized (see arrow S10). Then, after another trigger “please” is detected (see arrow A11), the words “temperature 28° C.” following the trigger are recognized (see Arrow S11). Thus, as for the triggers and the words other than the triggers intermittently spoken, the words spoken after the triggers are conventionally recognized.

However, it is difficult to perform voice speech recognition of the voice signal400of continuous utterance of words including multiple triggers, as illustrated inFIG. 7B. Specifically, upon detection of the first trigger “please” from the voice signal400, the words “turn on the air conditioner, please temperature 28° C.” are recognized from the next voice signal. Thus, although information on the detection of the trigger “please” can be displayed on the screen, the detection of the second trigger “please” cannot be displayed. In addition, referring toFIG. 3, the first trigger is “model number”, the second trigger is “voltage”, the “model number” is alphabets, and the “voltage” is expressed in numbers and unit. To be able to improve voice speech recognition accuracy, the model number “AAB” needs to be recognized referring to a voice speech recognition dictionary for alphabets only, and the voltage “20 V” needs to be recognized referring to a voice speech recognition dictionary for numbers and unit only. However, the model-number part and the voltage part are recognized, referring to the same voice speech recognition dictionary, therefore, voice speech recognition accuracy cannot be improved.

For another example, upon detection of the trigger “please” from the voice signal400(see arrow A10), voice speech recognition of a section S10′ subsequent to the trigger “please” starts. Upon detection of the subsequent trigger “please” (see arrow A11) during the voice speech recognition of the section S10′, the voice speech recognition of the section S10′ is nullified, so that a section S11′ subsequent to the second detected trigger “please” is not recognized.

In addition, conventional voice speech recognition may not deal with continuous speech without pause between the trigger and the speech after the trigger and between the speech and the next trigger, and it may fail to detect the triggers and perform voice speech recognition of the speech after the trigger.

Thus, as for continuous speech of words including multiple triggers, conventional voice speech recognition may fail to recognize at least part of the words following the triggers from the voice signal400, resulting in decrease in voice speech recognition accuracy with respect to the speech following the triggers.

Further, conventional voice speech recognition uses only a dictionary containing no trigger sound sections (corresponding to the voice speech recognition dictionary26C of the present embodiment) for the voice signal400. Because of this, conventional voice speech recognition may fail to recognize words following the triggers due to failure in identification of the end of the trigger or the head of the word caused by missing in the head of the word or entry of noise.

By contrast, in the information processing apparatus10according to the present embodiment, the voice speech recognizer12C performs voice speech recognition of the trigger sound section T of the detected trigger and the recognition sound section S subsequent to the trigger sound section T in the voice signal40, in accordance with the trigger and voice speech recognition dictionary26B corresponding to the detected trigger, to thereby acquire a result of voice speech recognition of the recognition sound section S. In addition, the trigger and voice speech recognition dictionary26B is for deriving the result of voice speech recognition of the recognition sound section S not only from the trigger sound section T but both the trigger sound section T and the recognition sound section S.

Thus, the information processing apparatus10according to the present embodiment can perform voice speech recognition, without omission, of the recognition sound sections S subsequent to the trigger sound sections T of all the triggers included in the voice signal40. That is, for continuous utterance of multiple words including multiple triggers, the information processing apparatus10according to the present embodiment can perform voice speech recognition of the recognition sound sections S continuously following all the triggers contained in the voice signals40of the utterance, referring to the dictionary corresponding to the detected triggers.

As a result, the information processing apparatus10according to the present embodiment can provide improved voice speech recognition.

FIG. 8AandFIG. 8Bare explanatory drawings of voice speech recognition of a first modification. For example, suppose that the user U speak “please turn on the air conditioner and set at 28° C.” and a voice signal41of the speech be subjected to voice speech recognition. Also, suppose that the words “please” and “set” in the voice signal41serve as triggers.

In this case, the detector12B reads the voice signal41from the head in chronological order, and executes trigger detection (see arrow A20). The detector12B reads the trigger sound section of the trigger “please” in the voice signal41and detects the trigger “please”. The voice speech recognizer12C performs voice speech recognition of a unitary section B10including the trigger sound section, referring to the trigger and voice speech recognition dictionary26B corresponding to the trigger ID of the detected trigger “please”, in the same manner as in the above embodiment.

The detector12B continues trigger detection (see arrow A21), and reads and detects the trigger “set”. The voice speech recognizer12C performs voice speech recognition of the unitary section including the trigger sound section, referring to the trigger and voice speech recognition dictionary26B corresponding to the trigger ID of the detected trigger “set” in the same manner as in the above embodiment.

Thereby, in the first modification, the information processing apparatus10can switch the trigger and voice speech recognition dictionaries26B for the voice speech recognition of terms representing devices such as “air conditioner” after the trigger “please” and for the voice speech recognition of the number “28” after the trigger “set”, thereby achieving accurate voice speech recognition.

The triggers (trigger words) may be set in advance or added by the user. For example, the output controller12D displays a list of less frequently used voices and/or words on the display18. With the display, the output controller12D presents the list of the voices and/or words to the user. The controller12may set voices and/or words selected in accordance with a user's operation to the input22as the triggers.

Second Modification

When a speaker emitting voice can be estimated, the information processing apparatus10may prepare combinations of triggers and speakers in advance. Speaker estimation refers to identifying the individual who has emitted the voice from the voice signal acquired by the voice acquirer12A. Due to the prepared combinations of triggers and speakers, the controller12can change the voice speech recognition dictionaries (trigger and voice speech recognition dictionary26B and voice speech recognition dictionary26C) for the same trigger word, if a different speaker speaks the trigger word.

Further, the information processing apparatus10may additionally include the combinations of triggers and speakers to thereby validate or invalidate the result of voice speech recognition in accordance with speaker information. For example, the controller12may output a result of recognition as a control signal without change when the speaker is the administrator and speaks the control of a device, but may terminate voice speech recognition for a certain period of time when detecting the trigger spoken by the speaker being a general user.

Hardware Configuration

Next, the hardware configuration of the information processing apparatus10according to the embodiment will be described.FIG. 9is a block diagram illustrating an exemplary hardware configuration of the information processing apparatus10according to the embodiment.

The information processing apparatus10according to the embodiment has a hardware configuration of a general computer, including a CPU80, a read only memory (ROM)82, a random access memory (RAM)84, a HDD86, and an interface (I/F)88mutually connected through a bus90.

The CPU80is an arithmetic unit that controls information processing of the information processing apparatus10according to the embodiment. The RAM84stores therein data required for various types of processing performed by the CPU80. The ROM82stores therein a program for implementing various types of processing by the CPU80. The HDD86stores therein data to be stored in the voice audio data storage24and the storage26. The interface88is an interface for transmitting and receiving data to and from other devices.

The program to execute the various types of processing by the information processing apparatus10according to the embodiment is incorporated and provided in advance in the ROM82, for example.

Programs to be executed by the information processing apparatus10according to the embodiment may be recorded and provided in installable or executable file format on a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, a digital versatile disc (DVD).

Programs to be executed by the information processing apparatus10according to the embodiment may be stored on a computer connected to a network such as the Internet, and downloaded and provided through the network. The program to execute the various types of processing by the information processing apparatus10according to the embodiment may be provided or distributed through a network, such as the Internet.

The program to execute the various types of processing in the information processing apparatus10according to the embodiment is configured to generate the above elements on the main storage device.

The various types of information may be stored in an external device in place of the HDD86. In this case, the external device and the CPU80are connected through a network.