JP4467459B2 - Audio signal control method and apparatus - Google Patents

Description

  The present invention relates to an audio signal control method and apparatus, and more particularly, to an audio signal control method and apparatus for controlling an audio signal input to headphones or earphones based on a wearing state of these headphones with respect to ears.

As shown in FIG. 6, the headphones have a structure in which left and right housings 1L and 1R are attached to an adjustable head pad 2, and ear pads 3L and 3R with built-in speakers are attached to the housing. 1R incorporates a substrate 11 and a battery 12 on which an audio circuit including a DSP and an amplifier is mounted. There is also a structure in which an audio circuit is provided on the source side and an audio signal is input to a speaker by a cord or wirelessly. The ear pads 3L and 3R include a type that is pressed against the user's ear EAR as shown in FIG. 7A and a type that covers the ear as shown in FIG. 7B.
According to such headphones, music can be enjoyed even in environments where there is no sound or noisy surroundings, and it is possible to listen to clear sounds that are not found in speakers, regardless of room conditions. Has advantages.
However, when the headphone is normally placed on the head and set on the ear, if the head pad 2 is too long, the ear pad part indicated by 13 in FIG. 8 floats from the ear and the ear pad cannot be sealed, and the head pad 2 is short. If too large, the ear pad portions indicated by 14 and 15 in FIG. If the length of the head pad 2 is adjusted carefully, it can be prevented from floating, but there are few people who adjust in this way, and it is often used while floating.
However, when the ear pad portion is lifted, the bass is reduced as shown in FIG. (A) shows the frequency characteristics when the ear pad normally seals the ear. For this reason, the user increases the volume and listens, but the volume is increased too much, and there is a problem that the ear is damaged by long-time use.
There is a prior art technique for correcting an increase in the mid-high range that occurs when the distance between the ear and the sound unit in the headphones is shortened to raise the bass level (see, for example, Patent Document 1). However, this prior art does not prevent the volume from being raised excessively by automatically detecting the lift of the ear pad portion and raising the bass.
JP 10-32892 A

From the above, the object of the present invention is to automatically detect the misalignment of the ear pad part, that is, to lift the ear pad part to emphasize the bass.
Another object of the present invention is to automatically emphasize the bass when a misplacement (floating) of the ear pad portion is detected, thereby eliminating the need for volume operation.

According to the present invention, there is provided an audio signal control method for controlling an audio signal input to a headphone or an earphone according to the present invention. Sensors are attached to the left and right ear pads of the phon, and the left and right ear pads are monitored by comparing the detection signals of the left and right ear pads by comparing the sensing signals of the sensors. Emphasizes the low frequency range of the left channel audio signal when the mounting state of the abutment is shifted, and emphasizes the low frequency range of the audio signal of the right channel when the mounting state of the right ear pad is shifted. This is achieved by an audio signal control method. The low frequency emphasis control is performed by separating the low frequency component of the audio signal, boosting the low frequency component and adding it to the audio signal, or generating the low frequency harmonic component of the audio signal. This is done by adding to the signal.
In addition, according to the present invention, in the audio device for controlling an audio signal input to headphones or earphones, the left and right ear pads are attached to the left and right ears of the audio device that controls the audio signals input to the headphones or earphones. Two or more pressure sensing sensors for detecting the state of each, a wearing displacement detection unit for comparing the sensing signals of the sensors for each of the left and right ear pads, and checking whether the wearing state of the left and right ear pads of the phone is shifted; When the left ear pad is worn out, the low frequency of the left channel audio signal is emphasized. When the right ear pad is worn out, the right channel audio signal is low. This is achieved by an audio device including a low-frequency emphasis circuit that emphasizes . The low frequency emphasis circuit includes a separation unit that separates a low frequency component of the audio signal, a boost unit that boosts the low frequency component, an addition unit that adds the boosted low frequency component to the audio signal, or a low frequency component of the audio signal. A separation unit that separates a band component, a harmonic component generation unit that generates a harmonic component of the low-frequency component, and an addition unit that adds the harmonic component to the audio signal.

  According to the present invention, two or more pressure sensing sensors for detecting the wearing state of the headphones or earphones to the ears are attached to the ear pad portions of the headphones or earphones, and the sensing signals of the sensors are compared to compare the earphones of the headphones or earphones. Since the low frequency range of the audio signal is emphasized if it is floating, the low range of the audio signal can be automatically detected and the low sound can be emphasized. In addition, according to the present invention, it is possible to automatically emphasize the bass when the lifting of the ear pad portion is detected, thereby making the volume operation unnecessary. As a result, there is no problem that the volume is increased too much and the ear is damaged by long-term use.

  In an audio signal control method for controlling an audio signal input to a headphone, two or more pressure detection sensors (strain gauges) for detecting a mounting state of the headphone on an ear are attached to an ear pad portion (ear pad) of the headphone, The sensor signal is compared to monitor whether the ear pad is misaligned, that is, whether the ear pad is floating, and if it is floating, the low frequency range of the audio signal is emphasized. For example, separating a low frequency component of an audio signal, boosting the low frequency component and adding it to the audio signal, or generating a low harmonic component of the audio signal and adding it to the audio signal To emphasize the low range.

 FIG. 1 is an external view of a headphone according to the present invention, in which left and right housings 51L and 51R are attached to a head pad 52 whose length can be adjusted, and ear pads 53L and 53R with built-in speakers are attached to the housing. The housings 51L and 1R incorporate a substrate 54 and a battery 55 on which an audio circuit including a DSP and an amplifier is mounted. Further, each of the ear pads 53L and 53R has two or more pressure sensors such as strain gauges A, B,... For detecting the displacement of the ear pads, that is, the state where the ear pads are floating at the ear. . . Is provided. Note that an audio circuit may be provided on the source side, and an audio signal may be input to the speaker by code or wirelessly.

  For example, as shown in FIG. 2A, four strain sensors A to D are arranged at intervals of 90 degrees, and the ear pads are connected to the upper strain gauges A and D. The pressure contact state to the upper ear is detected, and the pressure contact state to the ear below the ear pad is detected by the lower strain gauges B and C. If the upper and lower strain sensors detect the same strain, it is determined that there is no wearing deviation (floating) and the ear pad is in close contact with the ear, otherwise it is determined that there is a lift. Alternatively, as shown in FIG. 2 (B), two strain sensors A to B are arranged at an interval of 180 degrees, and the upper strain gauge A detects the pressure contact state to the ear on the upper side of the ear pad, and the lower strain gauge B Then, the pressure contact state of the ear pad on the lower side of the ear pad is detected, and the presence or absence of floating is determined as in the case of (A). Alternatively, as shown in FIG. 2 (C), three strain sensors A to C are arranged at intervals of 120 degrees, and these three strain sensors A to C are used for pressure contact at the upper part of the ear pad, diagonally lower left, and diagonally lower right. If the state is detected and each strain sensor detects an equivalent strain, it is determined that there is no float and the ear pad is in close contact with the ear, otherwise it is determined that there is a float.

FIG. 3 is a block diagram of the audio apparatus of the present invention. SP _L and SP _R are left and right speakers accommodated in the ear pads 53L and 53R in FIG. 1, and S _{A to SD} are shown in FIG. It is a strain signal of strain gauges A to D. The left and right mounting state detection units 61 _L and 61 _R have the same configuration, detect the presence or absence of mounting displacement (floating) between the left and right ear pads, and input a floating detection signal to the microcomputer 71. For example, in the left ear pad wearing state detection unit 61 _L , the differential amplifier 62a calculates the difference between the distortion signals S _A and S _C , and the differential amplifier 62b calculates the difference between the distortion signals S _D and S _B , The absolute value circuits 63a and 63b calculate and output the absolute value of each difference signal. Comparing unit 64a, 64b compares the respective absolute value and the threshold value L _R, OR gate 65 is the absolute value of any of the difference signal is greater than the threshold L _R, the left ear pad is attached in close contact with the peripheral ear However, it is determined that a float is generated above or below, and a float detection signal is input to the microcomputer 71. Similarly, the right ear pad wearing state detection unit 61 _R determines that the right ear pad is lifted and inputs a lift detection signal to the microcomputer 71.
The microcomputer 71 instructs the DSP (Digital Signal Processor) 72 to emphasize the low frequency component due to the occurrence of floating when a floating detection signal indicating that floating has occurred in the left or right ear pad. DSP 72 is if lifting occurs in the left ear pad, enter the left amplifier 73 to emphasize the low frequency component of an audio signal AS _L of the left channel, if lifting occurs in the right ear pad, right inputting right amplifier 74 to emphasize the low frequency component of an audio signal AS _R channels. By emphasizing this low frequency component, the decrease in the low frequency component due to the floating of the ear pad is automatically compensated, and the volume operation becomes unnecessary.

FIG. 4 shows an embodiment of the DSP 72, which shows the configuration of the left channel, but the configuration of the right channel is the same. The output switching unit 81 and the selector 82 perform output switching and audio signal selection in accordance with instructions MC1 and MC2 from the microcomputer 71. That is, if there are floating is generated on the left side of the ear pad, the output switching unit 81 outputs the audio signal AS _L to the output terminal OUT1, the selector 82 selects the audio signal to be output from the output switching unit 81 DSP Input to the processing unit 83. The DSP processing unit 83 performs normal DSP processing such as equalizing processing and volume processing, and inputs the result to the amplifier 73.
On the other hand, if the float is generated on the left side of the ear pad, the output switching unit 81 outputs the audio signal AS _L to the output terminal OUT2. The high-pass filter 84 extracts and outputs a high frequency component of a predetermined frequency or higher (for example, 100 Hz or higher) of the audio signal input from the output terminal OUT2, and the low-pass filter 85 extracts a low frequency component of the audio signal of 100 Hz or lower. Output. The low-frequency boost circuit 86 boosts (emphasizes) the power of the low-frequency component in accordance with the bass emphasis instruction from the microcomputer 71, and the synthesis unit 87 outputs the high-frequency component output from the high-pass filter 84 and the low-frequency boost circuit 86. The low frequency components are synthesized and input to the selector 82. The selector 82 selects the output signal of the synthesizing unit 87 because the float is generated, and the DSP processing unit 83 performs normal DSP processing of the sound quality and volume on the audio signal output from the synthesizing unit 87 to the amplifier 73. input. The high-pass filter 84 is not always necessary, and the degree of bass boost can be controlled according to the degree of floating (the output levels of the absolute value circuits 63a and 63b).

FIG. 5 shows another embodiment of the DSP 72, and the same components as those in FIG. The difference is that the high-pass filter 84 is deleted, a delay circuit 90 is provided instead, and a harmonic generation circuit 91 is provided instead of the low-frequency boost circuit 86 to emphasize the low sound. If lifting occurs in the left ear pad, the output switching unit 81 outputs the audio signal AS _L to the output terminal OUT2. The low-pass filter 85 extracts a low frequency component of a predetermined frequency or lower, for example, 100 to 200 Hz or lower, and the harmonic overtone generation circuit 91 doubles the frequency of the extracted low frequency component in accordance with the bass emphasis instruction MC3 from the microcomputer 71. The overtone signal is generated, the delay circuit 90 delays the audio signal for the time required for overtone generation, and the synthesis unit 87 synthesizes the overtone signal of the low frequency component output from the overtone generation circuit 91 with the delayed audio signal and supplies it to the selector 82. input. The selector 82 selects the output signal of the synthesizing unit 87 because the float has occurred, and the DSP processing unit 83 performs normal DSP processing on the audio signal output from the synthesizing unit 87 and inputs it to the amplifier 73.
Harmonics generating circuit 91, for example, temporarily store the digital audio data AS _L of the sampling frequency fs in the memory, and thereafter, the harmonic signal by reading the digital audio data from the memory at twice the sampling frequency 2fs 2 consecutive times Is generated. Even if the low frequency component disappears from the audio signal, if the overtone is included in the audio signal, it sounds as if the low frequency component is present in the sense of hearing. As a result, with the configuration of FIG. 5, even if the low frequency component is reduced due to the floating of the ear pad, it can be compensated by adding overtones.
In FIG. 5, it is possible to control the amplitude of the harmonic overtone according to the degree of floating of the ear pad (the output level of the absolute value circuits 63a and 63b).
As described above, according to the present invention, it is possible to automatically detect the float of the ear pad and emphasize the bass, and the volume operation becomes unnecessary, and the problem of damaging the ear by excessively increasing the volume can be eliminated.
The headphone has been described above, but the same can be applied to the earphone.

It is an external view of the headphones of the present invention. It is explanatory drawing of the attachment method of a strain gauge. It is a block diagram of the audio apparatus of this invention. This is an embodiment of a DSP. It is another Example of DSP. It is an external view of the conventional headphones. It is type explanatory drawing of an ear pad. It is floating explanatory drawing from the ear | edge of an ear pad. It is a frequency characteristic figure when an ear pad floats.

Explanation of symbols

51L, 51R Left and right housing 52 Head pad 53L, 53R Ear pad 54 Audio circuit board mounted
A, B Pressure sensor, eg strain gauge

Claims (6)

In an audio signal control method for controlling an audio signal input to a headphone or an earphone,
Two or more pressure sensitive sensors which detect the mounting state of the left and right ear parts of the left and right ears of the Hong attached to ear portions of the left and right of the Hong,
For each of the left and right ear pads , compare the sensing signals of each sensor and monitor whether the left and right ear pads of the phone are worn out of place,
When the left ear pad is worn out, the low frequency of the left channel audio signal is emphasized . When the right ear pad is worn out, the right channel audio signal is low. the emphasis,
An audio signal control method. 2. The audio signal control method according to claim 1, wherein the low frequency component of the audio signal is emphasized by separating the low frequency component of the audio signal, boosting the low frequency component and adding the boosted component to the audio signal. 2. The audio signal control method according to claim 1, wherein a low frequency overtone component of the audio signal is generated and added to the audio signal to emphasize the low frequency range of the audio signal. In an audio device that controls audio signals input to headphones or earphones,
2 or more pressure detection sensor attached to the ear portions of the left and right of the Hong respectively detect the mounting state of the left and right ears of the ear portions of the left and right,
For each left and right ear pad, a mounting displacement detector that compares the sensing signals of each sensor and checks whether the left and right ear pads of the phone are misaligned,
When the left ear pad is worn out, the low frequency of the left channel audio signal is emphasized . When the right ear pad is worn out, the right channel audio signal is low. low-frequency emphasis circuit to emphasize,
An audio device comprising: The low frequency emphasis circuit is
A separation unit that separates low-frequency components of the audio signal;
A boost unit for boosting the low frequency component,
An additional part that adds the boosted low frequency component to the audio signal,
The audio apparatus according to claim 4, further comprising: The low frequency emphasis circuit is
A separation unit that separates low-frequency components of the audio signal;
A harmonic component generator for generating a harmonic component of the low frequency component;
An adding unit for adding the harmonic component to the audio signal;
The audio apparatus according to claim 4, further comprising:

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