JP5729771B2 - Echo generation prevention device, telephone apparatus including the device, echo generation prevention method, and echo generation prevention program - Google Patents

Description

  The present invention relates to an echo generation prevention device, a telephone device including an echo generation prevention device, an echo generation prevention method, and an echo generation prevention program for preventing echo generation in a device such as a telephone.

  Echo cancellers are widely used to remove echoes in devices that input and output audio such as hands-free telephones.

  Here, there are two types of echo cancellers used in hands-free phones: acoustic echo canceller (AEC: Acoustic echo canceller) and line echo canceller (LEC: Line echo canceller) that cancels line echo. Commonly used.

  An example of a telephone provided with such an echo canceller is described in Patent Document 1. In the technique described in Patent Document 1, an input of a telephone number is received by voice when in a hands-free call state. Then, AEC is used as an echo canceller to remove the echo generated at this time.

  The echo canceller estimates the echo and synthesizes it with the transmission signal or the reception signal by shifting the phase of the signal having the same shape as the estimated echo by 180 °. The principle is that the echo estimated in this way is subtracted from the transmission signal or reception signal. And since it is such a principle, the echo canceller requires some time for the process of estimating and canceling the echo.

  For this reason, a large echo or howling due to this echo occurs at the start of a hands-free call. In this respect, the line echo varies greatly depending on the line used, but the acoustic echo does not change significantly unless the installation environment of the telephone is changed. Therefore, for acoustic echo, by estimating the echo at the time of the first call and storing the estimated value, appropriate estimation based on the measured value at the time of the previous call is made for the second and subsequent calls. The value can be used again, and a large echo and howling caused by this echo can be suppressed.

  For example, Patent Document 2 describes a technique for acquiring an appropriate filter coefficient of an acoustic echo canceller more quickly without delaying the start of voice processing such as a call. Specifically, the filter coefficient for removing the echo component between the speaker and the microphone is learned based on the sound transmitted from the content in the videophone device. The echo component is removed by using this filter coefficient at the start of a call with the other party. As a result, it is possible to remove the echo component from the start of the call.

JP-A-6-054042 JP 2012-134923 A

  However, the estimated values and filter coefficients as described above are values optimized for the removal of echo components during a call state. Therefore, when these numbers are used when inputting the dial number, the following problems have occurred.

  For example, consider a case where a dial number is input by pressing a button. In this case, as shown in FIG. 1, the user's hand 2000 presses the dial button 1001. Then, since an acoustic short-circuit transmission path is formed between the speaker 1002 and the microphone 1003, the sound output from the speaker 1002 is reflected on the user's hand 2000 and input to the microphone 1003 as it is. In this case, a hand shield exists in a space that does not originally have a shield, reflection is increased, and the attenuation is also reduced. Therefore, the acoustic echo 3000 is increased as compared with a call state. Accordingly, the telephone having such a structure has a problem that howling occurs if the amount of increase in the acoustic echo 3000 is large even if the estimated value or filter coefficient stored during the previous call is used. . Even when the telephone recognizes a phone number uttered from the mouth of a person close to the microphone and thereby obtains a signal of the phone number, a face close to them is placed between the speaker 1002 and the microphone 1003. An acoustic short circuit transmission line is formed, and the same phenomenon occurs.

  In addition, when receiving an input of a telephone number by voice as in Patent Document 1, there is a problem that howling occurs because the estimated values and filter coefficients stored during the previous call are not always appropriate. It was.

  In addition, if the estimated value or filter coefficient is corrected to a value corresponding to a special situation such as an increase in acoustic echo due to reflection by hand, the estimated value saved during the previous call or The filter coefficient changes and is not a value appropriate for the call state. For this reason, an echo occurs at the beginning of the call after the dial number is entered.

  Therefore, the present invention provides an echo that can suppress echo generated at the time of dial input or the like and howling associated therewith even under special circumstances such as an increase in acoustic echo compared to during a call. It is an object of the present invention to provide a generation prevention device, a telephone device including an echo generation prevention device, an echo generation prevention method, and an echo generation prevention program.

According to a first aspect of the present invention, there is provided an echo generation preventing device for preventing echo generation in a telephone device including a sound collection unit and a voice output unit, the sound collected by the sound collection unit. Mute means for muting so that a signal representing sound including at least the sound output from the audio output unit is not transmitted to a telephone line connected to the telephone device, the sound collection unit, and the audio output unit, The mute means is configured to perform the mute during a predetermined period including at least a period in which an acoustic short-circuit transmission path is formed by a user's human body close to these parts for inputting a telephone number. Control means for controlling, when the input of the telephone number is started, the control means converts all digits of the telephone number based on the first predetermined number of digits of the inputted telephone number. Predict and all the digits Echo prevention device forces characterized that you finished the predetermined time period when the ends are provided.
According to a second aspect of the present invention, there is provided an echo generation preventing device for preventing echo generation in a telephone device comprising a sound collection unit and a sound output unit, wherein the sound collected by the sound collection unit A mute means for muting so that a signal representing a sound including at least the sound output from the audio output unit is not transmitted to a telephone line connected to the telephone device, the sound collecting unit, and the audio output The mute is performed for a predetermined period including at least a period in which an acoustic short-circuit transmission line is formed by a user's human body close to these parts for inputting a telephone number. Control means for controlling the means, wherein the control means specifies the call destination and starts to speak a series of voices for making a call to the call destination to the sound collection unit. And then The user echo prevention device, characterized in that to end the predetermined time period if the detected that finished talking the series of speech is provided.

Furthermore, according to a third aspect of the present invention, there is provided a telephone device including a sound collecting unit and an audio output unit, and in order to prevent the occurrence of echo, the first aspect of the present invention or the present invention There is provided a telephone device characterized by further comprising an echo generation preventing device provided by the second aspect.

Further, according to a fourth aspect of the present invention, there is provided an echo generation preventing method for preventing echo generation in a telephone device comprising a sound collection unit and a sound output unit, wherein the sound collected by the sound collection unit A mute step for muting so that a signal representing a sound including at least the sound output from the audio output unit is not transmitted to a telephone line connected to the telephone device, and the sound collecting unit and the between an audio output unit, a predetermined period including at least a period in which the acoustic short circuit transmission line is formed by the body of the user in proximity to these parts for telephone number input, it performs the mute, When the input of the telephone number is started, all the digits of the telephone number are predicted based on the first predetermined number of digits of the input telephone number, and when the input of all the digits is completed, the predetermined number to terminate the period of time Echo prevention and wherein is provided.
Furthermore, according to a fifth aspect of the present invention, there is provided an echo generation preventing method for preventing echo generation in a telephone device comprising a sound collection unit and an audio output unit, the sound collected by the sound collection unit A mute step for muting so that a signal representing a sound including at least the sound output from the audio output unit is not transmitted to a telephone line connected to the telephone device, and the sound collecting unit and the The mute is performed for a predetermined period including at least a period in which an acoustic short-circuit transmission path is formed by a user's human body close to these parts for inputting a telephone number between the voice output unit, and It is detected that the user has specified a call destination and started to speak a series of voices for making a call to the call destination to the sound collecting unit, and further, the user plays the series of voices. Detecting that you ’ve finished speaking Echo prevention method characterized by terminating the predetermined period is provided if the.

Furthermore, according to a sixth aspect of the present invention, there is provided an echo generation prevention program for causing a computer to function as an echo generation prevention device for preventing echo generation in a telephone device comprising a sound collection unit and a voice output unit, The computer is configured so that a signal representing a sound collected by the sound collecting unit and including at least a sound output from the sound output unit is not transmitted to a telephone line connected to the telephone device. A period in which an acoustic short-circuit transmission line is formed between the sound collecting unit and the sound output unit by a user's human body close to these parts for inputting a telephone number. during a predetermined period including at least, and a control means for controlling said muting means to perform the mute, the control means, if the input of the telephone number has been initiated, Based on the first predetermined number of digits of the telephone number that is a force, to predict all the digits of the telephone number, the function as an echo prevention device exit the predetermined time period when all the digits of the input is terminated An echo generation prevention program is provided.
Furthermore, according to a seventh aspect of the present invention, there is provided an echo generation prevention program for causing a computer to function as an echo generation prevention device for preventing echo generation in a telephone device comprising a sound collection unit and an audio output unit, The computer is configured so that a signal representing a sound collected by the sound collecting unit and including at least a sound output from the sound output unit is not transmitted to a telephone line connected to the telephone device. A period in which an acoustic short-circuit transmission line is formed between the sound collecting unit and the sound output unit by a user's human body close to these parts for inputting a telephone number. Control means for controlling the mute means to perform the mute for a predetermined period including at least the control means, wherein the control means specifies the call destination and calls the call If it is detected that a series of voices for making a call to the sound collection unit has started to be spoken, and if it is detected that the user has finished speaking the series of voices, the predetermined voice There is provided an echo generation prevention program that functions as an echo generation prevention device for ending a period.

  According to the present invention, it is possible to suppress echo generated at the time of dial input or the like and howling associated therewith even under a special situation such as an increase in acoustic echo compared to during a call.

It is a conceptual diagram showing generation | occurrence | production of the acoustic echo by a user's hand. It is a block diagram showing the fundamental composition of the 1st embodiment of the present invention. It is a flowchart (1/2) showing the basic operation | movement of the 1st Embodiment of this invention. It is a flowchart (2/2) showing the basic operation | movement of the 1st and 2nd embodiment of this invention. It is a block diagram showing the basic composition of the 2nd Embodiment of this invention. It is a flowchart (1/2) showing the basic operation | movement of the 2nd Embodiment of this invention.

  First, an outline of an embodiment of the present invention will be described. In the embodiment of the present invention, a button detection unit for detecting dial input caused by pressing a dial button and a DTMF signal detection unit for detecting dial input by sound such as a DTMF (Dual-Tone Multi-Frequency) dialer are provided. Detect dial input. Also, since the total number of digits of the phone number can be determined by the first few digits, the total number of digits of the phone number is determined based on the detected dial input information. The transmission signal representing the input voice from the microphone being dialed is muted, and the acoustic echo canceller and the line echo canceller remain in a stopped state. Thereby, the echo at the time of dialing or a telephone call start, and the howling accompanying this can be suppressed. On the other hand, the DTMF signal is generated by the DTMF signal generation unit based on the dial detection information and is input to the line side from the transmission mute unit, so that only the DTMF signal can be transmitted to the line.

  The above is the outline of the embodiment of the present invention.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 2 shows the hands-free telephone 100 and the line 116 to which the hands-free telephone 100 is connected according to the first embodiment of the present invention.

  Referring to FIG. 2, the hands-free telephone 100 includes a dial button 101, a button detection unit 102, a microphone 103, a speaker 104, an AEC 106, a control unit 108, a storage unit 109, a count unit 110, and a mute. A switch 111, a DTMF signal generation unit 112, an LEC 113, and a line interface unit 114 are included. Further, FIG. 2 illustrates a transmission signal 105, a reception signal 115, an acoustic echo 117, and a line echo 118.

  Each of these parts functions as follows.

  The dial button 101 is a button for inputting a telephone number or the like, and accepts an input of a telephone number or the like from a user. The dial button 101 may be realized by assigning a number to each physical key, but may be realized as a soft key displayed on the touch panel, for example.

  The button detection unit 102 detects that the dial button 101 has been pressed, and recognizes which number is assigned to the pressed button. The recognized number is output to the control unit 108.

  The microphone 103 inputs a user's voice and converts the inputted voice into an electric signal. The converted electric signal is output to the mute switch 111 as the transmission signal 105. The transmission signal 105 is echo-removed by adding a cancel signal from the AEC 106 in the middle of the route output to the mute switch 111 by the adder 119.

  The speaker 104 converts the other party's voice received via the line 116 as the received signal 115 from an electrical signal to voice. The speaker 104 outputs the converted sound. The received signal 115 received via the line 116 is echo-removed by adding a cancel signal from the LEC 113 in the adder 120 in the middle of the route output to the speaker 104.

  The AEC 106 is an acoustic echo canceller. The AEC 106 estimates the acoustic echo 117 and generates a cancel signal having a phase opposite to that of the estimated value. The adder 119 removes the acoustic echo 117 from the transmission signal 105 by causing the cancel signal and the transmission signal 105 to interfere with each other.

  The control unit 108 controls the AEC 106, the storage unit 109, the count unit 110, the mute switch 111, and the LEC 113. Note that the control unit 108 may further control the entire hands-free telephone 100.

  The storage unit 109 is a storage unit that stores information on the total number of digits of the telephone number. Here, the total number of digits information of the telephone number will be described.

  The telephone number has a total number of digits corresponding to which number is the first one-digit or several-digit number. Taking Japan as an example, the total number of digits of a telephone number starting from “1” is 3 digits, the total number of digits of a telephone number starting from “080” or “090” is 11 digits, and so forth. In the present embodiment, it is assumed that the storage unit 109 stores a correspondence relationship indicating what number the total number of digits is when the first one-digit or several-digit number is.

  That is, the control unit 108 collates the information about which number is the first one-digit or several-digit number output from the button detection unit 102 with the information stored in the storage unit 109. Even when the user is entering the telephone number, the total number of digits of the telephone number that the user is about to call can be determined.

  The count unit 110 increments the count value by one via the control unit 108 every time the telephone number input is detected by the button detection unit 102. As a result, the control unit 108 can determine what number of the current telephone number has been input by referring to the count value of the count unit 110.

  The mute switch 111 mutes the transmission signal 105 according to the control of the control unit 108. The output signal of the mute switch 111 is equal to the input signal of the mute switch 111 when not muted, but represents zero as the mute state when muted. If the mute switch 111 handles analog signals, the unmuted state is a state in which the input terminal and the output terminal are connected, and the muted state is the state in which the input terminal and the output are output. The terminal is disconnected. If the mute switch 111 handles a digital signal, the state where the mute is not performed means that the output data is equal to the input data, and the state where the mute is performed means that the output data is zero. State. In the following description, the mute state is appropriately referred to as “mute state”, and the unmuted state is referred to as “non-mute state”.

  The DTMF signal generation unit 112 generates a DTMF signal corresponding to the telephone number detected by the button detection unit 102 under the control of the control unit 108. The generated DTMF signal is output to the line 116 via the line interface unit 114. Here, the DTMF signal generated by the DTMF signal generation unit 112 corresponds to a “calling signal” of the present invention.

  Adder 121 adds the signal output from mute switch 111 and the signal output from DTMF signal generator 112. Then, the addition unit 121 outputs the added signal to the line 116 via the line interface unit 114.

  Here, as described above, when the mute switch 111 is in the mute state, the output of the mute switch 111 represents zero. Therefore, when the mute switch 111 is in the mute state and the DTMF signal generation unit 112 outputs a DTMF signal, the output of the addition unit 121 is only the DTMF signal generated by the DTMF signal generation unit 112. On the other hand, when the mute switch 111 is in a non-mute state, the transmission signal 105 output from the microphone 103 is directly output from the adder 121. As will be described later in the description of the operation of the present embodiment, in the present embodiment, it is not assumed that the DTMF signal generator 112 outputs a DTMF signal when the mute switch 111 is in a non-muted state.

  The LEC 113 is a line echo canceller. The LEC 113 estimates the line echo 118, and generates a cancel signal having a phase opposite to that of the estimated value. The adder 120 removes the line echo 118 from the received signal 115 by causing the cancel signal and the line echo 118 to interfere with each other.

  The line interface unit 114 is an interface for connecting the handsfree telephone 100 and the line 116. The transmission signal 105 is output to the line via the line interface unit 114, and the reception signal 115 is similarly received via the line interface unit 114.

  The line 116 is an arbitrary telephone network, and generates a line echo 118 that is a reflected wave of a signal generated due to impedance mismatch of the terminal end of the transmission path or the conversion unit.

  Further, when the microphone 103 collects the sound output from the speaker 104, an acoustic echo 117 is generated. Also, howling occurs when the acoustic echo 117 increases.

  Each functional block described above can be realized by hardware. For example, the control unit 108 and the count unit 110 may be realized by a control IC (Integrated Circuit), and the AEC 106 and the LEC 113 may be realized by a digital signal processor (DSP). In addition, each functional block may be realized by cooperation of software and hardware.

  Note that only functional blocks directly related to the gist of the present embodiment are shown in FIG. 2, and other elements as a telephone such as a power source and a display unit are not shown. In addition, what is shown in FIG. 2 is merely an example of the configuration of the present embodiment, and the purpose of prohibiting the addition of other components or the replacement with other components is shown. Is not.

  Next, the basic operation of this embodiment will be described with reference to the flowchart of FIG. 3A and the flowchart of FIG. 3-2.

  First, when the handsfree telephone 100 is activated, the control unit 108 stops the operations of the AEC 106 and the LEC 113 (steps S11 and S13), and sets the respective echo estimation values to initial values (steps S12 and S14). In the flowchart of FIG. 3A, the process for the AEC 106 is performed after the process for the AEC 106 is performed. However, this is an example, and the process for the AEC 106 may be performed after the process for the LEC 113 is performed. The processing for and the processing for the LEC 113 may be performed in parallel.

  Next, the control unit 108 clears the counter of the count unit 110 (step S15) and sets the mute switch 111 to the transmission mute state (step S16). It should be noted that any of the processes in steps S15 and S16 may be performed in the same manner as in steps S11 to S14. That is, step S16 may be performed after performing step S16, or may be performed in parallel.

  Thereafter, it waits until the hands-free telephone 100 is off-hooked (No in step S17). When hands-free telephone 100 is off-hooked (Yes in step S17), hands-free telephone 100 is connected to line 116 and enters a telephone number input waiting state (No in step S18).

  At this time, since the transmission is muted by the mute switch 111, howling does not occur even if the acoustic echo 117 is increased by the hand pressing the dial button 101. Further, since the operation of the AEC 106 is stopped, echo estimation in a state where the acoustic echo 117 is increased is not performed. Thereby, the correction of the estimated value according to a special situation in which the acoustic echo increases due to reflection by the hand is not performed. Therefore, it is possible to prevent a situation in which a call starts with an estimated value corresponding to a special situation.

  When a telephone number is input by pressing dial button 101 (Yes in step S18), button detection unit 102 detects this input and transmits the detected telephone number information to control unit 108 (step S20).

  The control unit 108 transmits the telephone number information output from the button detection unit 102 to the DTMF signal generation unit 112. Furthermore, the DTMF signal generation unit 112 generates a DTMF signal based on the telephone number information output from the control unit 108, and transmits the DTMF signal to the line 116 via the line interface unit 114 (step S21). Thereby, telephone number information can be transmitted to the line 116 without generating howling.

  Further, the control unit 108 increments the telephone number digit count value of the counting unit 110 by one.

  Next, the control unit 108 compares the input telephone number information, the telephone number digit count value, and the total digit number information of the telephone number stored in the storage unit 109 to determine whether the telephone number input is completed. (Step S23). As described above, the control unit 108 can determine the total number of digits with the first few digits. If the telephone number input has not yet been completed, or if the total number of digits cannot be determined because the first few digits have not been reached, the process again waits for input of the telephone number (in step S23). No).

  On the other hand, when the input of the telephone number is completed up to the last digit (Yes in Step S23), the control unit 108 sets the mute switch 111 to the non-mute state (Step S24) and connects the transmission signal from the microphone 103 to the line 116. At the same time, the AEC 106 and the LEC 113 are operated to enable a call (steps S25 and S26). Note that the processing order of steps S25 and S26 is not limited and can be executed in any order.

  Thereafter, the call is started when the call partner captures the line (step S27).

  In this embodiment, if the input up to the last digit of the telephone number is completed by performing the determination in step S23, steps S24 to S26 are performed immediately. Therefore, the period until the process proceeds to step S27 is extended as much as possible. be able to. Therefore, during this period, AEC 106 and LEC 113 can be adjusted. That is, the AEC 106 and the LEC 113 can be adjusted to at least a predetermined level before a call is started.

  While the call is continuing, the AEC 106 and the LEC 113 cancel the echo while performing the echo estimation (No in step S28).

  When the hands-free telephone 100 is on-hooked (Yes in step S28), the line 116 and the hands-free telephone 100 are disconnected and the call is terminated. At the same time, the control unit 108 stops the operations of the AEC 106 and the LEC 113 (step S29 and step S29). S30) Only the LEC 113 sets the echo estimation value to the initial value (step S31). Here, the reason is that the echo estimation value of only the LEC 113 is reset to the initial value, but the line echo 118 varies greatly depending on the characteristics of the line for each line used depending on the other party, and is used this time. This is because, in many cases, it is more appropriate to use the preset initial value than to use the estimated value in the line as it is.

  On the other hand, the acoustic echo 117 does not change greatly unless the installation environment of the telephone is changed. Therefore, instead of resetting the echo estimation value of the AEC 106 to the initial value, the value estimated this time is stored. Thereby, a large echo and howling at the start of the next call can be suppressed. That is, when performing step S29 this time, the echo estimation value related to the AEC 106 is stored in the storage unit 109, and when performing the next step S25, the echo estimation value related to the AEC 106 stored in the storage unit 109 is read, Used as the initial value of the echo estimate.

  Thus, in this embodiment, even if the acoustic echo 117 increases by a hand pressing the dial button 101, the operation of the AEC 106 is stopped and no echo estimation is performed during dialing. Therefore, it is not corrected to an echo estimation value according to a special situation in which the acoustic echo 117 is increased by a hand pressing the dial button 101, and as a result that the echo estimation value at the end of the call can be reused, At the start, the influence of an increase in the acoustic echo 117 when dialing can be eliminated.

  The present embodiment described above has the following advantageous effects.

  The first effect is that it is possible to suppress howling and echo that may occur during dial input.

  This is because the sound input from the microphone is muted by the mute switch while dial input is being performed.

  A second effect is that the dial input is automatically detected and the mute switch can be brought into a non-mute state immediately after the dial input is completed.

  The reason is that the total number of digits of the telephone number that the user is trying to dial can be grasped based on the first few digits of the input dial. Further, the count is performed every time the dial is input, and it is monitored whether or not the total number of digits has been reached.

  A third effect is that large echoes and howling at the start of a call can be suppressed.

  The reason is that by stopping the echo canceller at the time of dial input, the estimated value is not erroneously corrected according to a special situation such as an increase in acoustic echo due to reflection by hand. In other words, a large echo value is estimated when the hand is close, and the corresponding cancel signal is large. On the other hand, when the hand is separated, the echo estimate is smaller than that, and the hand is close. If a large cancel signal corresponding to the above is applied to the signal, excessive cancellation occurs. However, according to the present embodiment, this can be avoided. That is, the estimated value optimized for the call state is not changed to an estimated value according to a special situation.

  Next, a second embodiment of the present invention will be described with reference to the block diagram of FIG. 4 and the flowchart of FIG.

  Referring to FIG. 4, the hands-free telephone 200 according to the second embodiment is different from the hands-free telephone 100 according to the first embodiment in that a DTMF signal detection unit 207 is added. Regarding the other parts, the hands-free telephone 200 and the hands-free telephone 100 are the same.

  In the hands-free telephone 200, the dial button 201 and the button detection unit 202 can be omitted. Therefore, in order to clarify this fact, in FIG. 4, the dial buttons 201, the button detection unit 202, and the lines representing the connection with these are all represented by broken lines.

  The hands-free telephone 200 acoustically receives a DTMF signal from the outside, and makes a call based on the received DTMF signal. The DTMF signal is generated by an external device called a tone dialer and is input from the microphone 203.

  Instead of accepting the DTMF signal, the user's voice may be accepted by the microphone 203, and the DTMF signal may be generated inside the hands-free telephone 200. That is, the name of the other party registered in the phone book is received as a voice from the user, or the number is received as a voice from the user, and the voice is recognized as voice and converted into a DTMF signal based on the recognition result. The function may be included in the hands-free telephone 200. In this case, a functional block for converting such sound into a DTMF signal is provided after the microphone 203 and before the DTMF signal detection unit 207.

  The DTMF signal detection unit 207 is a part that detects a DTMF signal from the transmission signal 205. The DTMF signal detection unit 207 notifies the control unit 208 of the contents each time a DTMF signal is detected.

  In this regard, in the first embodiment, the button detection unit 102 detects the telephone number corresponding to the button press, and notifies the control unit 108 of the detected telephone number. And the control part 108 grasped | ascertained the input telephone number by this notification.

  On the other hand, in the second embodiment, the DTMF signal detected by the DTMF signal detection unit 207 is notified to the control unit 208, and the control unit 208 grasps the input telephone number by converting the DTMF signal into a telephone number. Will be. Note that the function sharing may be changed, and the DTMF signal detection unit 207 may convert the DTMF signal into a telephone number and notify the control unit 208 of the converted telephone number.

  In any embodiment, the DTMF signal generation unit 212 (or DTMF signal generation unit 112) generates a DTMF signal based on the telephone number information output from the control unit 208 (or control unit 108), The data is transmitted to the line 116 via the line interface unit 214 (or the line interface unit 114).

  Next, the basic operation of this embodiment will be described with reference to the flowchart of FIG.

  Since steps S11 to S17 are the same as those in the first embodiment, the description thereof is omitted.

  Here, if Yes in step S17, the hands-free telephone 200 is connected to the line 116 as in the first embodiment, and enters a telephone number input waiting state.

  Then, when a telephone number is input by pressing the dial button 201 (Yes in step S18), the process is advanced to step S20 as in the first embodiment. On the other hand, even if there is no input of a telephone number by pressing the dial button 201 (No in step S18), if the DTMF signal detection unit 207 detects a DTMF signal from the transmission signal 205, the process proceeds to step S20. In this case, the DTMF signal detected by the DTMF signal detection unit 207 in steps S20 to S23 is processed as telephone number information. Thereby, even if it is a case where a DTMF signal is acoustically received from the outside, the process similar to 1st Embodiment is realizable.

  After that, the same processing as Step S24 to Step S31 shown in FIG. 3-2 is performed. Since the processing content itself is the same as that of the first embodiment, the description thereof is omitted. In this regard, of course, after step S23 in FIG. 5A is finished, steps S24 to S31 shown in FIG. 3-2 are performed, and the subsequent “circled number 1” in FIG. It will follow the “1” with a circle.

  In the second embodiment, step S18 can be omitted, and is represented by a broken line in FIG.

  Further, as described above, in the second embodiment, instead of accepting the DTMF signal, the user's voice is accepted by the microphone 203, and the DTMF signal may be generated inside the hands-free telephone 200. Is possible.

  In the case of such modification, Yes is determined in step S19 when it is detected that the user starts speaking the voice (for example, the name of the other party in the telephone directory or the telephone number itself). To do.

  Here, first consider the case where the user inputs the telephone number itself by voice. In this case, each time a number of telephone numbers is recognized, the processing from step S20 to step S22 is performed, and step S18 to step S23 are repeated until the answer is Yes in step S23.

  On the other hand, first consider a case where the user inputs the name of the other party in the telephone directory by voice. In this case, the total number of digits of the telephone number is not known until the other party is specified, but the total number of digits and the telephone number itself are known when the other party is specified.

  Therefore, the process of step S20 is continued until the other party is specified, and DTMF signals for all digits of the telephone number are generated and transmitted when the other party is specified. Thereafter, all the processes can be realized by continuing the process from step S24.

  The present embodiment described above can achieve the same effects as those of the first embodiment even when the DTMF signal is acoustically received from the outside.

  Moreover, although the above-described embodiment is a preferred embodiment of the present invention, the scope of the present invention is not limited only to the above-described embodiment, and various modifications are made without departing from the gist of the present invention. Implementation in the form is possible.

  Note that the above hands-free telephone can be realized by hardware, software, or a combination thereof. The echo generation prevention method performed by the above-described hands-free telephone can also be realized by hardware, software, or a combination thereof. Here, “realized by software” means realized by a computer reading and executing a program.

  The program may be stored using various types of non-transitory computer readable media and supplied to the computer. Non-transitory computer readable media include various types of tangible storage media. Examples of non-transitory computer readable media include magnetic recording media (for example, flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (for example, magneto-optical disks), CD-ROMs (Read Only Memory), CD- R, CD-R / W, semiconductor memory (for example, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (random access memory)). The program may also be supplied to the computer by various types of transitory computer readable media. Examples of transitory computer readable media include electrical signals, optical signals, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.

  A part or all of the above-described embodiment can be described as in the following supplementary notes, but is not limited thereto.

(Supplementary note 1) An echo generation preventing device for preventing echo generation in a telephone device including a sound collecting unit and a voice output unit,
Mute for muting so that a signal that is collected by the sound collecting unit and includes a sound that includes at least the sound output from the sound output unit is not transmitted to a telephone line connected to the telephone device Means,
A predetermined period including at least a period in which an acoustic short-circuit transmission line is formed between the sound collecting unit and the voice output unit by a user's human body close to these parts for inputting a telephone number, Control means for controlling the mute means to perform the mute;
An echo generation preventing apparatus comprising:

(Supplementary note 2) The echo generation preventing device according to supplementary note 1, wherein
When the input of the telephone number is started, the control means predicts all the digits of the telephone number based on the first predetermined number of digits of the input telephone number, and the input of all the digits is performed. An echo generation preventing apparatus, wherein the predetermined period is terminated when the period is terminated.

(Supplementary note 3) The echo generation preventing device according to supplementary note 2, wherein
The input of the telephone number is performed by the user's operation on the dial button,
An echo generation preventing apparatus, further comprising means for detecting the telephone number input by the user's operation on the dial button.

(Appendix 4) The echo generation prevention device according to appendix 2,
The telephone number is input by inputting a DTMF tone to the sound collection unit,
An echo generation preventing apparatus, further comprising means for detecting the telephone number input by inputting the DTMF tone to the sound collection unit.

(Supplementary note 5) The echo generation preventing apparatus according to supplementary note 1, wherein
The control means starts the predetermined period when detecting that the user starts to speak the sound for specifying the call destination to the sound collecting unit, and the user specifies the call destination The echo generation preventing apparatus is characterized in that the predetermined period is ended if it is detected that the voice for the purpose has been beaten against the sound collecting unit.

(Appendix 6) The echo generation preventing apparatus according to any one of appendices 1 to 5,
The echo generation preventing apparatus, wherein the control means starts the predetermined period when the telephone device is switched to a hands-free state or when the telephone device is in an on-hook state.

(Supplementary note 7) The echo generation preventing device according to any one of supplementary notes 1 to 6,
Signal generating means for generating a call signal corresponding to the telephone number input by the user;
An adding means for adding the signal for calling generated by the signal generating means and the output signal of the mute means;
Further comprising
In the predetermined period, a signal given from the mute means to the adder means is a mute signal, and the adder does not include a signal from the sound collecting unit and includes a signal including the calling signal. An echo generation preventing apparatus for outputting to the telephone line.

(Supplementary note 8) The echo generation preventing device according to any one of supplementary notes 1 to 7,
An echo canceling means for removing an echo generated by the sound collecting unit collecting the sound output from the sound output unit;
Means for stopping the echo cancellation function by the echo cancellation means in the predetermined period, and restarting the echo cancellation function by the echo cancellation means when the predetermined period ends;
An echo generation preventing apparatus, further comprising:

(Supplementary note 9) The echo generation preventing device according to supplementary note 8, wherein
The echo cancellation means includes at least an acoustic echo canceller,
The control means uses the echo estimation value estimated by the acoustic echo canceller when stopping the function of the acoustic echo canceller as the initial value of the echo estimation value when restarting the function of the acoustic echo canceller next time. An echo generation prevention device characterized by causing the echo to occur.

(Additional remark 10) It is a telephone apparatus provided with a sound collection part and an audio | voice output part, Comprising: As an echo generation | occurrence | production prevention apparatus for preventing generation | occurrence | production of an echo,
An echo generation prevention device for preventing echo generation in a telephone device including a sound collection unit and a voice output unit,
Mute for muting so that a signal that is collected by the sound collecting unit and includes a sound that includes at least the sound output from the sound output unit is not transmitted to a telephone line connected to the telephone device Means,
A predetermined period including at least a period in which an acoustic short-circuit transmission line is formed between the sound collecting unit and the voice output unit by a user's human body close to these parts for inputting a telephone number, Control means for controlling the mute means to perform the mute;
A telephone apparatus, further comprising an echo generation preventing apparatus.

(Supplementary note 11) The telephone device according to supplementary note 10,
When the input of the telephone number is started, the control means predicts all the digits of the telephone number based on the first predetermined number of digits of the input telephone number, and the input of all the digits is performed. The telephone device characterized in that the predetermined period ends when it is ended.

(Supplementary note 12) The telephone device according to supplementary note 11, wherein
The input of the telephone number is performed by the user's operation on the dial button,
The telephone apparatus further comprising means for detecting the telephone number input by the user operation on the dial button.

(Supplementary note 13) The telephone device according to supplementary note 11, wherein
The telephone number is input by inputting a DTMF tone to the sound collection unit,
The telephone apparatus, further comprising means for detecting the telephone number input by inputting the DTMF tone to the sound collecting section.

(Appendix 14)
The telephone device according to attachment 10, wherein
The control means starts the predetermined period when detecting that the user starts to speak the sound for specifying the call destination to the sound collecting unit, and the user specifies the call destination The telephone device is characterized in that the predetermined period is ended if it is detected that the voice for the purpose has been spoken to the sound collecting unit.

(Supplementary note 15) The telephone device according to any one of supplementary notes 10 to 14,
The telephone device characterized in that the control means starts the predetermined period when the telephone device is switched to a hands-free state or when the telephone device is in an on-hook state.

(Supplementary note 16) The telephone device according to any one of supplementary notes 10 to 14,
Signal generating means for generating a call signal corresponding to the telephone number input by the user;
An adding means for adding the signal for calling generated by the signal generating means and the output signal of the mute means;
The echo generation prevention device further comprises
In the predetermined period, a signal given from the mute means to the adder means is a mute signal, and the adder does not include a signal from the sound collecting unit and includes a signal including the calling signal. A telephone device that outputs to the telephone line.

(Supplementary note 17) The telephone device according to any one of supplementary notes 10 to 16,
An echo canceling means for removing an echo generated by the sound collecting unit collecting the sound output from the sound output unit;
Means for stopping the echo cancellation function by the echo cancellation means in the predetermined period, and restarting the echo cancellation function by the echo cancellation means when the predetermined period ends;
The telephone apparatus further comprising the echo generation preventing device.

(Supplementary note 18) The telephone device according to supplementary note 17,
The echo cancellation means includes at least an acoustic echo canceller,
The control means uses the echo estimation value estimated by the acoustic echo canceller when stopping the function of the acoustic echo canceller as the initial value of the echo estimation value when restarting the function of the acoustic echo canceller next time. A telephone device characterized in that the telephone device is characterized.

(Supplementary note 19) An echo generation prevention method for preventing echo generation in a telephone device including a sound collection unit and an audio output unit,
Mute for muting so that a signal that is collected by the sound collecting unit and includes a sound that includes at least the sound output from the sound output unit is not transmitted to a telephone line connected to the telephone device Has steps,
A predetermined period including at least a period in which an acoustic short-circuit transmission line is formed between the sound collecting unit and the voice output unit by a user's human body close to these parts for inputting a telephone number, An echo generation prevention method, wherein the mute is performed.

(Supplementary note 20) The echo prevention method according to supplementary note 19, wherein
When the input of the telephone number is started, all the digits of the telephone number are predicted based on the first predetermined number of digits of the input telephone number, and when the input of all the digits is completed, the predetermined number An echo generation preventing method characterized by ending the period.

(Supplementary note 21) The echo generation preventing method according to supplementary note 20,
The input of the telephone number is performed by the user's operation on the dial button,
An echo generation preventing method, further comprising means for detecting the telephone number input by the user's operation on the dial button.

(Supplementary note 22) The echo generation preventing method according to supplementary note 20,
The telephone number is input by inputting a DTMF tone to the sound collection unit,
An echo generation preventing method, further comprising means for detecting the telephone number input by inputting the DTMF tone to the sound collecting unit.

(Appendix 23)
An echo generation preventing method according to appendix 19,
If it is detected that the user has started to speak the sound for specifying the call destination to the sound collecting unit, the predetermined period is started, and the sound for the user specifying the call destination is An echo generation preventing method, comprising: ending the predetermined period if it is detected that the sound collecting unit has been beaten.

(Supplementary note 24) The echo generation preventing method according to any one of supplementary notes 19 to 23, wherein
An echo generation prevention method, wherein the predetermined period is started when the telephone method is switched to a hands-free state or when the telephone method is in an on-hook state.

(Supplementary note 25) The echo generation preventing method according to any one of supplementary notes 19 to 24, wherein
A signal generation step of generating a call signal corresponding to the telephone number input by the user;
An adding step of adding the call signal generated by the signal generating means and the output signal of the mute means;
Further comprising
In the predetermined period, a signal given from the mute means to the adder means is a mute signal, and the adder does not include a signal from the sound collecting unit and includes a signal including the calling signal. An echo generation prevention method, characterized by outputting to the telephone line.

(Supplementary note 26) The echo generation preventing method according to any one of supplementary notes 19 to 25,
An echo cancellation step for removing echo generated by the sound collecting unit collecting the sound output from the sound output unit;
Further comprising
Stopping the echo cancellation function by the echo cancellation step in the predetermined period, and restarting the echo cancellation function by the echo cancellation means when the predetermined period ends,
An echo generation prevention method characterized by that.

(Supplementary note 27) The echo generation preventing method according to supplementary note 26,
The telephone includes at least an acoustic echo canceller;
When stopping the function of the acoustic echo canceller, the echo estimation value estimated by the acoustic echo canceller is used as an initial value of the echo estimation value when the acoustic echo canceller function is restarted next time. Echo generation prevention method.

  The present invention can be applied to any telephone as long as it is used for suppressing the occurrence of echo and howling.

100, 200 Hands-free telephone 101, 201 Dial button 102, 202 Button detector 103, 203 Microphone 104, 204 Speaker 105, 205 Transmission signal 106, 206 AEC
108, 208 Control unit 109, 209 Storage unit 110, 210 Count unit 111, 211 Mute switch 112, 212 DTMF signal generation unit 113, 213 LEC
114, 214 Line interface unit 115, 215 Received signal 116, 216 Line 117, 217 Acoustic echo 118, 218 Line echo 119, 120, 121, 219, 220, 221 Adder 207 DTMF signal detection unit 1001 Dial button 1002 Speaker 1003 Microphone 2000 User's Hand

Claims (11)

An echo generation prevention device for preventing echo generation in a telephone device including a sound collection unit and a voice output unit,
Mute for muting so that a signal that is collected by the sound collecting unit and includes a sound that includes at least the sound output from the sound output unit is not transmitted to a telephone line connected to the telephone device Means,
A predetermined period including at least a period in which an acoustic short-circuit transmission line is formed between the sound collecting unit and the voice output unit by a user's human body close to these parts for inputting a telephone number, Control means for controlling the mute means to perform the mute;
Equipped with a,
When the input of the telephone number is started, the control means predicts all the digits of the telephone number based on the first predetermined number of digits of the input telephone number, and the input of all the digits is performed. echo prevention device characterized that you finished the predetermined period upon completion. An echo generation prevention device for preventing echo generation in a telephone device including a sound collection unit and a voice output unit ,
Mute for muting so that a signal that is collected by the sound collecting unit and includes a sound that includes at least the sound output from the sound output unit is not transmitted to a telephone line connected to the telephone device Means,
A predetermined period including at least a period in which an acoustic short-circuit transmission line is formed between the sound collecting unit and the voice output unit by a user's human body close to these parts for inputting a telephone number, Control means for controlling the mute means to perform the mute;
With
The control means detects that the user has specified a call destination, starts to speak a series of voices for calling to the call destination to the sound collection unit, and further, the user The echo generation preventing apparatus, wherein the predetermined period is ended when it is detected that the series of voices has been spoken. The echo generation prevention device according to claim 1 or 2 ,
The echo generation preventing apparatus according to claim 1, wherein the control means starts the predetermined period when the telephone device is switched to a hands-free state or when the telephone device enters an on-hook state in the hands-free state. The echo generation preventing apparatus according to any one of claims 1 to 3 ,
Signal generating means for generating a call signal corresponding to the telephone number input by the user;
An adding means for adding the signal for calling generated by the signal generating means and the output signal of the mute means;
Further comprising
In the predetermined period, a signal given from the mute means to the adder means is a mute signal, and the adder does not include a signal from the sound collecting unit and includes a signal including the calling signal. An echo generation preventing apparatus for outputting to the telephone line. The echo generation preventing apparatus according to any one of claims 1 to 4 ,
An echo canceling means for removing an echo generated by the sound collecting unit collecting the sound output from the sound output unit;
Means for stopping the echo cancellation function by the echo cancellation means in the predetermined period, and restarting the echo cancellation function by the echo cancellation means when the predetermined period ends;
An echo generation preventing apparatus, further comprising: The echo generation preventing apparatus according to claim 5 ,
The echo cancellation means includes at least an acoustic echo canceller,
The control means uses the echo estimation value estimated by the acoustic echo canceller when stopping the function of the acoustic echo canceller as the initial value of the echo estimation value when restarting the function of the acoustic echo canceller next time. An echo generation prevention device characterized by causing the echo to occur. A telephone device including a sound collection unit and an audio output unit,
A telephone apparatus, further comprising the echo generation preventing apparatus according to any one of claims 1 to 6 , in order to prevent generation of echo. An echo generation prevention method for preventing echo generation in a telephone device including a sound collection unit and an audio output unit,
Mute for muting so that a signal that is collected by the sound collecting unit and includes a sound that includes at least the sound output from the sound output unit is not transmitted to a telephone line connected to the telephone device Has steps,
A predetermined period including at least a period in which an acoustic short-circuit transmission line is formed between the sound collecting unit and the voice output unit by a user's human body close to these parts for inputting a telephone number, When the input of the telephone number is started while the mute is performed , all the digits of the telephone number are predicted based on the first predetermined number of digits of the input telephone number, and the input of all the digits is performed. The echo generation preventing method is characterized in that the predetermined period is ended when the period ends .   An echo generation prevention method for preventing echo generation in a telephone device including a sound collection unit and an audio output unit,
  Mute for muting so that a signal that is collected by the sound collecting unit and includes a sound that includes at least the sound output from the sound output unit is not transmitted to a telephone line connected to the telephone device Has steps,
  A predetermined period including at least a period in which an acoustic short-circuit transmission line is formed between the sound collecting unit and the voice output unit by a user's human body close to these parts for inputting a telephone number, While performing the mute, it is detected that the user has specified a call destination, and has started to speak a series of voices for calling to the call destination to the sound collection unit, and further, the user The echo generation prevention method is characterized in that if it is detected that the voice has been spoken, the predetermined period is terminated. An echo generation prevention program for causing a computer to function as an echo generation prevention device for preventing echo generation in a telephone device including a sound collection unit and an audio output unit,
The computer,
Mute for muting so that a signal that is collected by the sound collecting unit and includes a sound that includes at least the sound output from the sound output unit is not transmitted to a telephone line connected to the telephone device Means,
A predetermined period including at least a period in which an acoustic short-circuit transmission line is formed between the sound collecting unit and the voice output unit by a user's human body close to these parts for inputting a telephone number, Control means for controlling the mute means to perform the mute;
Equipped with a,
When the input of the telephone number is started, the control means predicts all the digits of the telephone number based on the first predetermined number of digits of the input telephone number, and the input of all the digits is performed. echo prevention program for causing to function as an echo prevention device you exit the predetermined period upon completion. An echo generation prevention program for causing a computer to function as an echo generation prevention device for preventing echo generation in a telephone device including a sound collection unit and an audio output unit,
  The computer,
  Mute for muting so that a signal that is collected by the sound collecting unit and includes a sound that includes at least the sound output from the sound output unit is not transmitted to a telephone line connected to the telephone device Means,
  A predetermined period including at least a period in which an acoustic short-circuit transmission line is formed between the sound collecting unit and the voice output unit by a user's human body close to these parts for inputting a telephone number, Control means for controlling the mute means to perform the mute;
  With
  The control means detects that the user has specified a call destination, starts to speak a series of voices for calling to the call destination to the sound collection unit, and further, the user An echo generation preventing program that functions as an echo generation preventing apparatus that terminates the predetermined period if it is detected that the series of voices has been spoken.

Images