Audio output apparatus, document reading method, and mobile terminal

An audio output apparatus includes an audio output unit and a storage unit which stores a predetermined word and a type associated with the word. A controller, upon outputting an electronic document as audio from the audio output unit using speech synthesis, when the electronic document contains the word stored in the storage unit, controls the audio output from the audio output unit according to the type associated with the word.

CROSS REFERENCE TO RELATED APPLICATION

This application claims foreign priority based on Japanese Patent application No. 2005-158213 filed on May 30, 2005, the content of which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

This invention relates to an audio output apparatus and a document reading method.

Recently, in information communication terminals (audio output apparatuses), such as mobile telephones and personal computers (PCs), attention is being given to a function for analyzing character strings in an electronic document, such as an electronic mail, and using a speech synthesis technique to convert texts in the electronic document into speech. An information communication terminal including such a function enables a user to check the contents of an electronic document (message), such as an electronic mail, by means of sound. This increases the convenience of the information communication terminals by enabling the user to, for example, check the contents of an electronic document, such as an electronic mail by means of sound, while performing another operation on a mobile telephone or a PC monitor.

However, a text-to-speech function using a conventional speech synthesis technique outputs flat sound regardless of the content of the electronic document. This lack of speech intonation makes it uncomfortable for a user to listen to. To solve this problem, Japanese Unexamined Patent Application, First Publication No. 2004-289577 discloses a technique whereby, when transmitting an electronic mail from a sender mobile communication terminal, such as a mobile telephone, to a recipient mobile communication terminal, emotion identification information is appended to the electronic mail in accordance with its contents.

However, the aforementioned technique has shortcomings in that appending the emotion identification information to the electronic mail increases the data size of the electronic mail, and the user may be charged more fees for using electronic mail the data size of which increases. Moreover, when the emotion identification information is appended to a header of an electronic mail, the mail service system must be modified for being accommodated to this change of the header, requiring considerable network modification.

Another issue is that, if the mobile sender communication terminal is not equipped with a function for appending the emotion identification information, the recipient mobile communication terminal cannot determine any emotion.

The present invention has been made in consideration of the above problems, and the object thereof is to realize an audio output apparatus and a document reading method which include a text-to-speech function with a highly conventional emotional expression.

SUMMARY OF THE INVENTION

To achieve the aforementioned objects, this invention provides an audio output apparatus including: an audio output unit which outputs an audio, a storage unit which stores predetermined words and types associated with the words, and a controller which, upon outputting an electronic document as an audio from the audio output unit, when the electronic document contains the word stored in the storage unit, controls the audio output from the audio output unit according to the type associated with the word.

A first aspect of the present invention provides an audio output apparatus comprising: an audio output unit which outputs an audio; a storage unit which stores a predetermined word and a type associated with the word; a controller which, upon outputting an electronic document as an audio from the audio output unit using a speech synthesis, when the electronic document contains the word stored in the storage unit, controls the audio output from the audio output unit according to the type associated with the word.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, embodiments according to the present invention will be described with reference to the appended figures.

As an example of an audio output apparatus, the explanation of this embodiment describes a mobile communication terminal, for example a mobile telephone and the like, which is equipped with a function for transmitting and receiving electronic mails (messages).FIG. 1is a block diagram illustrating a functional configuration of a mobile communication terminal according to an embodiment of this invention. As shown inFIG. 1, the mobile communication terminal includes a wireless communication unit1, a key input unit2, a display unit3, a storage unit4, a controller5, and an audio output unit9. The controller5includes an emotion type determining unit6, a sound quality setting unit7, and a speech synthesizer8as its functional configuration elements.

The wireless communication unit1is controlled by the controller5, and uses a predetermined communication technique, such as a code division multiple access (CDMA) technique, to exchange audio signals and data signals, such as electronic mails, via wireless communications with a mobile communication base station. The key input unit2includes dial key buttons, function key buttons, a power key button, and the like, and outputs operation statuses of these buttons as operation signals to the controller5. The display unit3comprises, for example, a liquid crystal display apparatus which displays various types of messages, telephone numbers, images, and so on, based on display signals input from the controller5.

The storage unit4stores beforehand control programs executed by the controller5. In addition, the storage unit4is configured to sequentially store various types of data, such as telephone numbers and electronic mail addresses, under the control of the controller5, and to output these data to the controller5in response to requests from the controller5. The storage unit4also stores emotion type determination tables, such as those shown inFIGS. 2 to 4. As shownFIGS. 2 to 4, the emotion type determination tables list categories for each emotion type (affection, joy, comfort, displeasure, disappointment/unease, hardship, disappointment/annoyance, importance, and trouble), with words and weighted constants being stored for each category. The storage unit4also stores an urgency level determination table which stores categories relating to urgency levels, with words and weighted constants defined for each category, as shown inFIG. 5.

The controller5is configured to control the overall operation of the mobile communication terminal according to the predetermined control programs stored beforehand in the storage unit4, operation signals input from the key input unit2, the communication status of the wireless communication unit1, or the like. As characteristic control processing based on the control program, the controller5processes text data of the main text of an electronic mail received by the wireless communication unit1using the emotion type determining unit6and the speech synthesizer8.

The emotion type determining unit6compares the text data of the main text of the electronic mail with the emotion type determination table, extracts words corresponding to each emotion type from the text data, determines a sum of the weighted constant assigned to each word, determines the emotion type from the sum, and outputs an emotion type signal indicating the emotion type to the sound quality setting unit7. The emotion type determining unit6compares the text data with the urgency level determination table stored in the storage unit4, extracts the corresponding words, determines the urgency level from the sum of the weighted constants assigned in the words, and outputs an urgency level signal indicating the urgency level to the sound quality setting unit7. This processing operation of the emotion type determining unit6will be explained in detail later.

Based on the emotion type signal (i.e. the emotion type) sent from the emotion type determining unit6, the sound quality setting unit7sets the sound quality (pitch, volume, and intonation of speech) for reading an electronic mail, sets a reading speed for speech based on the urgency level signal (i.e. the urgency level), and outputs information related to the sound quality as speech setting information to the speech synthesizer8.

Based on the sound quality information, the speech synthesizer8converts the text data of the electronic mail to synthesized speech data, and outputs an audio signal representing this synthesized speech data to the audio output unit9. That is, the synthesized speech data is synthesized such that the electronic mail is read according to the urgency level and the emotion type determined by the emotion type determining unit6. The audio output unit9includes, for example, a speaker which converts the audio signal input from the speech synthesizer8to sound and outputs it to the outside.

Next, the text-to-speech conversion processing of electronic mails in a mobile communication terminal configured as described above will be explained using the flowchart ofFIG. 6.

In step S1, the mobile communication terminal (specifically, the wireless communication unit1) receives an electronic mail from another mobile communication terminal via a mobile communication base station. In this example, the received electronic mail (received mail) include text data of “after such a long hard time, finally we are meeting for a fun date. I have a present for you, so come quickly.” The text data may include the title of the electronic mail in addition to the main text thereof.

In step S2ofFIG. 7, the emotion type determining unit6in the controller5extracts words corresponding to each emotion type and the urgency level (in this case, “hard”, “fun”, “date”, “present”, and “quickly” are extracted) from the text data of the received mail according to the emotion type determination table and the urgency level determination table stored in the storage unit4. In step S3, the emotion type determining unit6determines the sum of the weighted constants assigned to the words as a sum (count value), and determines the emotion type and urgency level. For example, inFIG. 2, the word “fun” corresponds to the category “like” of the emotion type “affection”, and the weighted constant for “affection” is “20”, “fun” also corresponds to the category “joyful” related to the emotion type “joy”, and the weighted constant is “70”. As shown inFIG. 5, the word “quickly” corresponds to the urgency level category “urgent” and its weighted constant is “1”.

The emotion type determining unit6executes similar processing to fill in the table ofFIG. 7for each of the other words, and thereby calculates the sum of the weighted constants related to the emotion types and the urgency level. As shown inFIG. 7, since the largest sum of weighted constants in this embodiment is that related to the emotion type “joy”, the emotion type determining unit6determines “joy” as the emotion type of the received mail and “1” as its urgency level.

The emotion type determining unit6then determines whether an emotion type can be determined in step S4. If the largest sum of weighted constants calculated in step S2is known, the emotion type can be determined in step S3. Therefore, the determination in step S4is “Yes” and the emotion type determining unit6outputs an emotion type signal representing “joy” as the emotion type of the received mail and an urgency level signal representing “1” as its urgency level to the sound quality setting unit7. In step S5, the sound quality setting unit7sets the pitch, volume, and intonation of speech according to the emotion type “joy”, sets the reading speed according to the urgency level “1”, and outputs this information as sound quality setting information to the speech synthesizer8. The larger the value representing the urgency level is, the faster the reading speed becomes; the smaller the value, the slower the reading speed.

In step S6, based on the sound quality setting information, the speech synthesize8converts the text data of the received mail to synthesized speech data and outputs it as an audio signal to the audio output unit9. The audio output unit9converts the audio signal to sound and outputs it to the outside. This enables the received mail to be read aloud as an emotional speech.

There are cases where the maximum value cannot be determined among the total weighted constants related to the emotion types in step S3; that is, where there exists a plurality of emotion types with two or more categories whose sums are equal and are largest compared to other categories. Since it is difficult to determine the emotion type of the received mail in such cases, the emotion type determining unit6determines in step S4that an emotion type cannot be determined for such received mails, and proceeds to step S7.

In step S7, the emotion type determining unit6checks whether a transmission history corresponding to the received mail is stored in the storage unit4. That is, in step S7, it is determined whether the received mail is a reply mail to an electronic mail which was transmitted from the mobile communication terminal to another mobile communication terminal (transmitted mail).

If a determination of “No” is made in step S7(i.e. if the received mail is not a reply mail to a transmitted mail send from the mobile communication terminal), in step S8, the emotion type determining unit6outputs an emotion type signal indicating that an emotion type cannot be determined and an urgency level signal indicating the urgency level of the received mail to the sound quality setting unit7.

When the emotion type determining unit6determines that no emotion type can be determined for the received mail, in step S9, the sound quality setting unit7selects a standard setting (default setting), which does not express emotion as the speech setting information, and outputs it to the speech synthesizer8. This default setting uses only a setting related to an emotion type as the standard setting, the urgency level being set according to the urgency level of the received mail. In step S6, based on the default settings, the speech synthesizer8converts the text data of the received mail to synthesized speech data and outputs it as an audio signal to the audio output unit9. The audio output unit9converts the audio signal to sound and outputs it to the outside. Thus, when it is determined that an emotion type cannot be determined for a received mail and the received mail is not a reply mail, text-to-speech conversion is performed without emotional expression.

On the other hand, when a determination of “Yes” is made in step S7, that is, when the received mail is a reply mail to a mail transmitted from the mobile communication terminal, such as when the received mail has the same mail title as a mail retained in the history of transmitted mails, in step S10, the emotion type determining unit6obtains the text data of the transmitted mail stored in the transmitted mail folder of the storage unit4as a related message and, in step S11, determines an emotion type and an urgency level of the transmitted mail based on the text data thereof. The processing to determine the emotion type and the urgency level is the same as that of step S3and will not be explained further. In step S12, the emotion type determining unit6determines whether and emotion type can be determined for the transmitted mail.

If a determination of “Yes” is made in step S12, that is, if it is determined that an emotion type can be determined for the transmitted mail, the emotion type determining unit6outputs an emotion type signal indicating an emotion type and an urgency level signal indicating an urgency level of the transmitted mail to the sound quality setting unit7. In step S13, the sound quality setting unit7sets the pitch, volume, and intonation of speech according to the emotion type of the transmitted mail, sets the reading speed according to the urgency level of the transmitted mail, and outputs this information as sound quality setting information to the speech synthesizer8.

In step S6, based on the sound quality setting information, the speech synthesizer8converts the text data of the received mail to synthesized speech data and outputs it as an audio signal to the audio output unit9, which converts the audio signal to sound and outputs it to the outside. This enables the received mail to be read aloud as an emotional speech. Thus even if an emotion type cannot be determined for the received mail, if the received mail is a reply mail to a transmitted mail transmitted from the mobile communication terminal, since there is a high possibility that the transmitted mail and the reply mail, being related messages, have the same emotion types, the received mail can be given emotional expression and text-to-speech conversion can be performed by referring to the emotion type of the transmitted mail.

On the other hand, when a determination of “No” is made in step S12, that is, if it is determined that an emotion type cannot be determined for the transmitted mail, the emotion type determining unit6outputs an emotion type signal indicating that an emotion type cannot be determined and an urgency level signal indicating an urgency level of the received mail (reply mail) to the sound quality setting unit7.

When it is determined that an emotion type cannot be determined for the transmitted mail in this way, in step S14, the sound quality setting unit7selects a standard setting (default setting) which does not express emotion as the speech setting information, and outputs it to the speech synthesizer8. This default setting uses only a setting related to an emotion type as the standard setting, an urgency level setting being made according to the urgency level of the received mail. In step S6, based on the default setting, the speech synthesizer8converts the text data of the received mail to synthesized speech data, and outputs it as an audio signal to the audio output unit9, which converts the audio signal to sound and outputs it to the outside. Thus, when it is determined that the received mail is a reply mail and that emotion types cannot be determined for the reply mail and the transmitted mail, text-to-speech conversion is performed without emotional expression.

In steps S11to S14, an urgency level may be determined from the time interval between the transmission time of the transmitted mail and the reception time of the reply mail which is transmitted in reply to the transmitted mail, and the reading speed may be changed in accordance with that urgency level. For example, when the time interval is long, a low urgency level is determined and the reading speed is set to a slow speed. Conversely, when the time interval is short, a high urgency level is determined and the reading speed is set to a fast speed.

As described above according to this embodiment, since the information communication terminal (audio output apparatus) which receives an electronic mail (message) determines the emotion type of that received mail, an emotional text-to-speech conversion can be performed without providing the communication terminal sending information with a function for appending emotion type information. Furthermore, there is no need to input emotion type information every time the user transmits an electronic mail. Moreover, since a header of an electronic mail is not used, it is not necessary to change the mail service system, whereby the mail usage cost for users can be reduced. According to this embodiment, a mobile communication terminal including a text-to-speech function which is capable of expressing emotions can be made more convenient.

The present invention is not limited to the embodiment described above, and modifications such as the following are conceivable.

While in the aforementioned embodiment, weighted constants of emotion types associated with each word extracted from the electronic mail (electronic document) are counted and an emotion type of the electronic mail is determined based on the maximum value of the sum (count value) of the weighted constants of each emotion type, which is not to be considered as limiting the present invention. It would be acceptable to count occurrences of words used in the electronic mail (electronic document) for each emotion type and determine the emotion type of the electronic mail according to the emotion type having the highest count value.

While the aforementioned embodiment is embodied in a mobile communication terminal, this is not to be considered as limiting the present invention. The electronic mail reading unit of the invention can also be applied in an information communication terminal, such as a personal computer which transmits and receives electronic mails using a communication unit.

While the aforementioned embodiment is described using an emotion type determination table and an urgency level determination table, such as those inFIGS. 2 to 4andFIG. 5, these are merely examples and are not limiting the present invention. It is of course possible to set other emotion types, and other words, and the like in correspondence with them.

While in the aforementioned embodiment, based on the emotion type and the urgency level of the electronic mail, text-to-speech conversion is performed, characters, animations, and the like, corresponding to the emotion type and the urgency level may also be displayed on the display unit3.

While the aforementioned embodiment has been described using an example of speech synthesis of an electronic mail, the invention is not limited to this and can be applied for any other types of electronic documents having text data. In addition to electronic mails, the invention can be similarly used in relation to messages that are transmitted and received via online chat and the like using a short message service, push-to-talk (PTT) technique, and the like, and also when browsing websites and the like on the Internet.