JP2005086361A - Portable terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable terminal which automatically controls the call sound volume according to the level of the surrounding noise and the sending or receiving voice to/from a communication party. <P>SOLUTION: A controller 7 discriminates between a voice and noise in input electric signals from a microphone 2 thereto via an AD converter 6. When discriminating the noise in the input electric signals, the controller 7 controls the gain of an amplifier 4 for adjusting electric signals at the input side and that of an amplifier 3 for adjusting electric signals at the output side. When discriminating the voice in the input electric signals, the controller 7 controls the gain of the amplifier 4 for adjusting electric signals at the input side. When discriminating a voice in electric signals outputted from a codec 8, the controller 7 controls the gain of the amplifier 3 for adjusting electric signals at the output side. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a portable terminal device that automatically controls a call volume according to the level of ambient noise, the volume of sound transmitted to a communication partner, and the volume of sound received from the communication partner.

Conventionally, when a call is made with a mobile phone device or the like, the received voice is often difficult to hear due to ambient noise. For example, when the noise in a place where the mobile terminal device is used during a call increases, if the received sound volume is low, it becomes difficult for the caller to hear the call, and sometimes it is inaudible. On the other hand, when the noise at the place where the mobile terminal device is used is reduced during a call, if the received volume is high, the caller feels loud and the call leaks to the outside. Further, when the voice of the other party of the call is higher than the normal one, the call is leaked to the outside.

In an environment where such a mobile terminal device is used, it is possible to solve these problems by manually changing the volume of the call, but in an environment where the noise in the environment changes indefinitely over time, such as in a train or car When the volume of noise such as inside is changing every moment, or when the cause of noise such as trains, cars, and airplanes is approaching or leaving, the call volume must be changed manually. It is impossible to respond immediately to environmental changes.

Therefore, the difficulty in hearing the received volume is determined from the amount of change in the caller's transmitted voice level. When the amount of change in the transmitted voice level is large, the ambient noise level is detected, and the detected ambient noise level is determined. There has been disclosed a technique that can automatically set an optimum reception volume for a caller by setting the reception volume (see, for example, Patent Document 1).

JP-A-11-196174

However, Patent Document 1 requires a special microphone or the like for detecting the noise level separately, and there is a problem that the cost is increased.

The present invention solves the above-described problems and can automatically set an optimum reception volume for a caller with only a microphone for inputting an existing transmission sound and a speaker for outputting a reception sound. The purpose is to provide.

A portable terminal device according to claim 1 of the present invention is a control unit that determines whether a signal is an audio signal or a signal due to ambient noise based on a difference between a maximum level and a minimum level of an input signal level. When the control unit determines that the signal is an audio signal or a noise signal, the control unit performs a process of adjusting at least one signal level of the input or output signal according to the determination. Features.

According to the portable terminal device of the present invention, it is possible to automatically control the call volume according to the level of ambient noise, the volume of voice transmitted to the communication partner, and the volume of voice received from the communication partner. .

Hereinafter, the present invention will be described by way of examples. However, the following examples do not limit the claimed invention, and all combinations of features described in the examples serve as means for solving the invention. It is not always essential.

FIG. 1 is a diagram showing an example of the configuration of the main part of the mobile terminal device of the present invention. FIG. 1 shows a speaker unit 1 that converts an output electric signal into sound, a microphone unit 2 that converts sound into an electric signal and inputs it, and an AD converter 5 that converts the output electric signal from an analog level to a digital level. An AD converter 6 that converts an input electric signal from an analog level to a digital level, an amplifier unit 3 that adjusts the output electric signal, an amplifier unit 4 that adjusts the input electric signal, and an output Control of the amplifier unit 3 that reads the level of the AD converter 5 on the side and adjusts the electrical signal on the output side, and controls the amplifier unit 4 that reads the level of the AD converter 6 on the input side and adjusts the electrical signal on the input side. It comprises a control unit 7 that performs and a codec unit 8 that modulates and demodulates the audio signal.

Here, in the present invention, the configuration subsequent to the codec unit can be the same as that of a mobile terminal device that is generally distributed, and the configuration subsequent to the codec unit does not require any special configuration. Therefore, the configuration subsequent to the codec section is omitted, and in this case, the configuration upstream from the codec section necessary for applying the present invention will be described.

Next, the processing method of the present invention will be described. First, the electrical signal input from the microphone unit 2 is discriminated between voice and noise by the control unit 7 via the AD converter 6. Here, the voice and noise identification method will be described in detail later.

When the electrical signal input by the control unit 7 is identified as noise during the discrimination between the voice and the noise (this case is assumed to be (1)), the control unit 7 adjusts the electrical signal on the input side. Gain control of the amplifier unit 4 to be performed and the amplifier unit 3 to perform adjustment of the electric signal on the output side is performed. On the other hand, when the electrical signal input by the control unit 7 is identified as a voice (this case is (2)), the control unit 7 performs gain control of the amplifier unit 4 that adjusts the electrical signal on the input side. Do. Further, when the electrical signal output from the 7 codec unit 8 is identified as voice by the control unit (this case is referred to as (3)), the control unit 7 adjusts the electrical signal on the output side. Perform gain control. By performing the above processing, it is possible to perform gain control according to the discrimination between voice and noise. A detailed description of the input / output signal control method in the cases (1) to (3) in the parentheses will be given later.

Next, a method for discriminating between voice and noise will be described in detail with reference to FIG. FIG. 2 is a diagram showing signal levels of voice and noise. (A) of the figure shows the audio signal level, and (b) shows the noise signal level. Here, the vertical axis in the figure represents the signal level, the horizontal axis represents the time axis, and the arrow represents the sampling interval.

When the audio signal level (a) and the noise signal level (b) are compared on a specific time axis, the audio (a) is intonated. The level in time has a wide difference between the maximum value and the minimum value. In addition, since the noise (b) is not inflated, when the signal level is sampled, the level at the specific time becomes a value with a narrow difference between the maximum value and the minimum value.
Utilizing this, the electric signal level on the input side at a specific fixed time is always sampled at a specific time, and the difference between the maximum value and the minimum value of the level is detected, thereby detecting the electric signal. Can be identified as voice or noise.

Next, a method for controlling the input / output signal when the input electrical signal in the case (1) is identified as noise will be described in detail with reference to FIG. FIG. 3 is a diagram illustrating an example of a noise signal level. Here, (a) in FIG. 3 represents the noise signal level for a certain period, and (b) in FIG. 3 represents the noise signal level in the period following (a) in FIG. 3A and 3B, the vertical axis represents the signal level, the horizontal axis represents the time axis, and the dotted line represents the average of the noise signal level. 3C shows the average signal level of noise, FIG. 3D shows the output gain level of the amplifier unit 3 on the output side, and FIG. 3E shows the input of the amplifier unit 4 on the input side. Represents the gain level.

When the input electrical signal of the case (1) is identified as noise, the average signal level of noise at a certain time can be measured by measuring the signal level for the noise and averaging it. This operation is always repeated at regular intervals, and the average signal level of noise at a certain time (FIG. 3A) is compared with the average signal level of noise at the next time (FIG. 3B). The gain control of the amplifier unit 3 that adjusts the electric signal on the output side in proportion to the amount of change in the average signal level is performed. Similarly, the gain control of the amplifier unit 4 that adjusts the electric signal on the input side is performed in inverse proportion to the amount of change in the average signal level of the noise.

As a result, when the average signal level of noise increases, by increasing the gain of the amplifier 3 on the output side, it is possible to increase the volume of the call from the other party during noise and to prevent call interruption during noise It becomes. Similarly, when the average signal level of noise increases, by reducing the gain of the amplifier unit 4 on the input side, it is possible to reduce the volume of the call to the other party during noise and to prevent the other party from transmitting noise. It becomes. On the contrary, when the average signal level of noise is reduced, it is possible to set an optimum call environment by reducing the gain of the amplifier unit 3 on the output side and increasing the gain of the amplifier unit 4 on the input side in the same manner. it can.

When such processing is viewed as a change in the average noise signal level on the time axis as shown in FIG. 3C, the gain of the amplifier unit 3 on the output side is proportional to the average noise signal level (FIG. 3). (D)), and the gain of the amplifier 4 on the input side is inversely proportional to the noise level (FIG. 3 (e)). In this way, by adjusting the gain of the output-side amplifier unit 3 and the gain of the input-side amplifier unit 4 based on the average signal level of the noise that is always input, an optimal call environment is set. Is possible.

Next, a method for controlling the input signal when the input electrical signal in the above-described case (2) is identified as voice will be described in detail with reference to FIG. FIG. 4 is a diagram illustrating an example of a sound signal level. Here, (a) in FIG. 4 represents the audio signal level for each certain period, and (b) in FIG. 4 represents the audio signal level in the period following (a) in FIG. 4A and 4B, the vertical axis represents the signal level, the horizontal axis represents the time axis, and the dotted line represents the average of the audio signal levels. (C) in FIG. 4 represents the average signal level of audio, and (d) in FIG. 4 represents the input gain level of the amplifier unit 4 on the input side.

When the input electrical signal in case (2) is identified as voice, the average signal level of the voice at a certain time can be measured by measuring and averaging the level of the voice. This operation is always repeated at regular time intervals, and the average signal level of the voice at a certain time (FIG. 4 (a)) is compared with the average signal level of the voice at the next time (FIG. 4 (b)). The gain control of the amplifier unit 4 that adjusts the electric signal on the input side according to the amount of change in the average signal level is performed.

Thereby, when the average signal level of the voice increases, it is possible to send a certain level of voice to the other party by reducing the gain of the amplifier 4 on the input side. On the other hand, when the average signal level of the voice is reduced, the optimum call environment can be set by increasing the gain of the amplifier 4 on the input side.

When such processing is viewed as a change in the average audio signal level on the time axis as shown in FIG. 4C, the gain of the amplifier unit 4 on the input side is inversely proportional to the audio level (FIG. 4D ))become. In this way, by adjusting the gain of the amplifier unit 4 on the input side based on the average signal level of the sound that is always input, it is possible to set an optimal call environment.

Finally, a method for controlling the output signal when the electrical signal output from the 7 codec unit 8 in the above-described case (3) is identified as speech will be described in detail with reference to FIG. FIG. 5 is a diagram illustrating an example of the audio signal level. Here, (a) in FIG. 5 represents the audio signal level for each period, and (b) in FIG. 5 represents the audio signal level in the period following (a) in FIG. 5A and 5B, the vertical axis represents the signal level, the horizontal axis represents the time axis, and the dotted line represents the average of the audio signal levels. (C) in FIG. 5 represents the average signal level of the sound, and (d) in FIG. 5 represents the output gain level of the amplifier unit 3 on the output side.

When the electrical signal output from the codec unit 8 in the case (3) is identified as voice, the average signal level of the voice at a certain time can be measured by measuring the level of the voice and averaging it. it can. This operation is always repeated at regular intervals, and the average signal level of the sound at a certain time (FIG. 5A) is compared with the average signal level of the sound at the next time (FIG. 5B), and the sound is The gain control of the amplifier unit 3 that adjusts the electrical signal on the output side is performed in accordance with the amount of change in the average signal level.

As a result, when the average signal level of the sound increases, the sound output from the speaker unit 1 can be kept at a constant level by reducing the gain of the amplifier unit 3 on the output side. On the other hand, when the average signal level of the voice is reduced, an optimum call environment can be set by increasing the gain of the amplifier unit 3 on the output side.

When such processing is viewed as a change in the average audio signal level on the time axis as shown in FIG. 5C, the gain of the amplifier unit 3 on the output side is inversely proportional to the average audio signal level (FIG. 5). (C)). In this way, by adjusting the gain of the amplifier unit 3 on the output side based on the average signal level of the sound that is always output, it is possible to set an optimal call environment.

As described above, according to the best embodiment of the present invention, by automatically increasing / decreasing the sound level from the other party according to the amount of noise in the environment where the mobile terminal device is used, It is possible to prevent the telephone call from being interrupted.

Further, during a call, the volume of the call to the other party can be made constant by automatically increasing or decreasing the level of the sound according to the volume of the voice sent to the other party. Similarly, by automatically increasing / decreasing the level of the voice according to the volume of the voice from the other party, the call volume from the other party can be made constant. As a result, it is possible to prevent problems such as voice leakage to the outside due to a change in the call volume from the other party, and troubles such as a call volume being low to the other party.

The figure which shows an example of a structure of the main part of the portable terminal device of this invention. The figure which shows the signal level of an audio | voice and noise. The figure which shows an example of the signal level of noise. The figure which shows an example of the signal level of an audio | voice. The figure which shows an example of the signal level of an audio | voice.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Speaker part 2 Microphone part 3, 4 Amplifier part 5, 6 AD converter 7 Control part 8 Codec part

Claims (1)

A mobile terminal device comprising a control unit for determining whether a signal is an audio signal or a signal due to ambient noise based on a difference between a maximum level and a minimum level of an input signal level,
When it is determined that the control unit is an audio signal or a noise signal, the control unit performs a process of adjusting a signal level of at least one of an input signal and an output signal according to the determination.

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