JP6880862B2 - Headphones - Google Patents

Description

The present invention relates to headphones.

In recent years, portable external devices such as smartphones have become widespread. In many cases, the user wears headphones and listens to music or the like output from the external device at a volume set by the user himself / herself. In addition, so-called noise-canceling headphones that reduce ambient sounds and allow users to listen to music and the like are also becoming widespread (see Patent Document 1).

JP-A-2017-005413

By the way, a kind of acoustic trauma called headphone deafness is becoming a problem. This headphone deafness is a symptom in which the cochlea of the inner ear is impaired by listening to loud music or the like with headphones for a long period of time, resulting in a decrease in hearing.
The present invention has been made in view of such circumstances, and one of the objects thereof is to provide a technique capable of preventing headphone deafness.

In order to achieve the above object, the headphones according to one aspect of the present invention include an adjusting unit for adjusting the volume of an input signal, a sounding body for sounding based on the signal whose volume is adjusted by the adjusting unit, and the sounding. When the sound pressure of the output sound by the sounding body is estimated based on the microphone that collects the output sound by the body and the sound collection signal by the microphone, and the integrated value of the estimated sound pressure becomes equal to or more than a predetermined threshold value. Also includes a volume changing unit that instructs the adjusting unit to change the volume to a small value.

It is a figure which shows the headphone which concerns on embodiment. It is a block diagram which shows the structure of a headphone. It is a figure which shows an example of the time threshold table. It is a figure which shows the operation example of a headphone.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a headphone 1 according to an embodiment. As shown in this figure, the headphone 1 has a substantially cylindrical shape, and includes a headphone unit 5L for the left ear, a headphone unit 5R for the right ear, and a headband 3 for connecting the headphone units 5L and 5R. Have.

The headband 3 is formed of an elastic metal, resin, or the like to form an outer shape that draws an arc in the longitudinal direction. In each of the headphone units 5L and 5R, an annular and elastic ear pad 10 is provided inside the arc in the headband 3.

In the headphone unit 5L, the sounding body 12L is provided substantially in the center of the annulus on the ear pad 10. The microphone 14L is provided in the ring of the ear pad 10 and in the vicinity of the sounding body 12L.
Further, a dial 16a and an LED (Light Emitting Diode) 19 are provided on the side surface of the cylinder in the headphone unit 5L, and the cord 18 is pulled out from the side surface. The code 18 inputs a stereo signal supplied from an external device. In the present embodiment, the stereo signal is input by wire via the code 18, but it may be received wirelessly by infrared rays, wirelessly, or the like.

Further, in the headphone unit 5R, the sounding body 12R is provided at substantially the center of the annulus of the ear pad 10, and the microphone 14R is provided in the annulus of the ear pad 10 and in the vicinity of the sounding body 12R.
Each of the sounding bodies 12L and 12R converts an electric signal into a sound of physical vibration and outputs it, and a speaker is typically used.

The dial 16a is a knob for adjusting the volume set by the user. In the example shown in the figure, the volume is set by the user rotating the dial 16a. For example, a push button for increasing the volume and a push button for decreasing the volume are provided, and the number of times the push button is pressed or the pressing time of the push button is provided. The volume may be set according to the above.

When wearing the headphone 1, the user holds the headphone units 5L and 5R to widen the arc of the headband 3 and puts each of the ear pads 10 on his or her auricle. The ear pads 10 attached to each of the headphone units 5L and 5R generate a restoring force that tries to bring the ends closer to each other due to the elasticity of the headband 3, so that a lateral pressure is applied to the user's head. Due to this lateral pressure, the headphone 1 is held in a predetermined position when worn.

When the user wears the headphone 1 in this way, the sounding body 12L and the microphone 14L are located in the closed space of the ear pad 10, so that the microphone 14L picks up the sound output by the sounding body 12L. It will be. Similarly, the microphone 14R also collects the sound output by the sounding body 12R when the user wears the headphone 1.

FIG. 2 is a block diagram showing an electrical configuration of the headphone 1. As shown in this figure, the headphone 1 includes sounding bodies 12L, 12R, microphones 14L, 14R, code 18, LED 19, adjusting unit 30, volume changing unit 40, amplifiers 55L and 55R.

In the headphone 1, the signal processing of the left channel and the signal processing of the right channel in the stereo signal are almost the same. Therefore, first, the system for processing the left channel will be described first.
Of the stereo signals input via the code 18, the signal Lin for the left channel is supplied to the adjusting unit 30. The adjusting unit 30 includes multipliers 32L and 32R and a coefficient output unit 34. The signal Lin supplied to the adjusting unit 30 is supplied to the multiplier 32L. The multiplier 32L multiplies the signal Lin by the coefficient supplied from the coefficient output unit 34 and supplies the signal to the amplifier 55L.
The coefficient output unit 34 outputs a coefficient corresponding to the volume set by the dial 16a. The coefficient output unit 34 changes the coefficient when instructed by the volume changing unit 40 as described later, regardless of the setting of the dial 16a.

The amplifier 55L amplifies the multiplication signal by the multiplier 32L at a predetermined amplification factor and supplies it to the sounding body 12L.
On the other hand, the microphone 14L collects the sound output by the sounding body 12L as described above, and supplies the sound collecting signal to the volume changing unit 40.

The system for processing the right channel in the stereo signal is the same as that for the left channel. That is, the multiplier 32R multiplies the right channel signal Rin by the coefficient from the coefficient output unit 34 among the stereo signals input via the code 18, and the amplifier 55R multiplies the multiplier signal by the multiplier 32R. It is amplified at a predetermined amplification factor and supplied to the sounding body 12R. On the other hand, the microphone 14R collects the sound output by the sounding body 12R and supplies the sound collecting signal to the volume changing unit 40.

The volume changing unit 40 includes a conversion unit 42 and a discriminating unit 44.
The conversion unit 42 inputs the sound collection signals of the microphones 14L and 14R, converts the amplitude value of each sound collection signal into a sound pressure value, and supplies the sound pressure value to the discrimination unit 44. Specifically, the conversion unit 42 has, for example, a table in which the amplitude value and the sound pressure value are associated in advance, converts the amplitude value of the sound collection signal into the sound pressure value with reference to the table, and converts the sound into the sound pressure value. The pressure value is supplied to the discrimination unit 44. The conversion unit 42 may calculate the amplitude value of the sound pick-up signal by a predetermined calculation instead of the table.

The discrimination unit 44 executes a process including the following discrimination on the sound pressure value supplied from the conversion unit 42, and gives an instruction according to the result of the discrimination.
Specifically, first, the discriminating unit 44 measures the usage time (elapsed time) from the start of use of the headphone 1 (for example, when the power is turned on). Secondly, the discriminating unit 44 calculates the time average value (sound pressure average value) over the elapsed time for the left and right sound pressure values supplied from the conversion unit 42. Specifically, the discrimination unit 44 integrates the left and right sound pressure values supplied from the conversion unit 42 at predetermined time intervals (for example, every 1 second) from the start of use, and divides the integrated value by the elapsed time. To calculate the average sound pressure value. Third, the discriminating unit 44 determines whether or not the elapsed time is equal to or greater than the time threshold value corresponding to the average sound pressure value.

FIG. 3 is a diagram showing an example of a table that defines the relationship between the average sound pressure value and the time threshold value. In this figure, for example, if the average sound pressure value is 92 dB or more and less than 94 dB, the time threshold value is 1 hour, and if the average sound pressure value is less than 85 dB, the time threshold value is 8 hours. It is shown that.
This table is provided to prevent headphone deafness that may occur when listening at an excessive volume, and is defined from the viewpoint that it is not preferable for a person to be exposed to noise for a longer period of time. Will be done. Note that this table is just an example, and is actually set in consideration of various test results and safety margins.

Fourth, if the discriminating unit 44 determines that the elapsed time is less than the time threshold value, the discriminating unit 44 instructs the adjusting unit 30 to output a coefficient having a value corresponding to the setting of the dial 16a, while the elapsed time. If it is determined that the time is equal to or greater than the time threshold value, the coefficient output unit 34 is instructed to output a coefficient of zero regardless of the setting of the dial 16a, and the LED 19 is turned on.

Next, the operation of the headphone 1 will be described.
FIG. 4 is a diagram for explaining the operation of the headphone 1. In the figure, X indicates a change over time in the average sound pressure value.
If the average sound pressure value is not 101 dB or more at the start of use of the headphone 1, the determination unit 44 determines that the elapsed time from the start of use is less than the time threshold value corresponding to the average sound pressure value. Therefore, the coefficient output unit 34 outputs a coefficient corresponding to the value set by the dial 16a. Therefore, the user wearing the headphone 1 can listen to music or the like by an external device at a volume adjusted by the dial 16a by himself / herself.

On the other hand, when the time T elapses from the start of use, when the determination unit 44 determines that the elapsed time is equal to or greater than the time threshold value corresponding to the sound pressure average value at that time, the coefficient output unit 34 outputs a coefficient of zero regardless of the setting of the dial 16a.
As a result, the user wearing the headphones 1 will not be able to listen to music or the like from an external device thereafter, so that it is possible to prevent headphone deafness due to excessive listening. Further, when it is determined that the elapsed time is equal to or greater than the time threshold value corresponding to the average sound pressure value, the LED 19 lights up to warn the user, so that the user can know the state of over-listening.

If the average sound pressure value is 101 dB or more at the start of use, the discriminating unit 44 immediately determines that the sound pressure is equal to or higher than the time threshold value, so that the headphones 1 cannot listen to music or the like.

The present invention is not limited to the above-described embodiment, and various applications and modifications as described below are possible, for example. It should be noted that one or a plurality of arbitrarily selected modes of application / modification described below can be appropriately combined.

In the above-described embodiment, the sound pick-up signals by the microphones 14L and 14R are used only for calculating the average sound pressure value, but may be used for other purposes such as noise cancellation. Specifically, the sound picked up signal by the microphone 14L is reversed in phase (polarity is inverted) and added to the reverse phase signal and the signal Lin, while the sound picked up signal by the microphone 14R is reversed in phase. It may be configured to add the opposite phase signal and the signal Rin. According to this configuration, the ambient sound perceived by the user can be reduced.

In the embodiment, when it is determined that the elapsed time is equal to or greater than the time threshold value corresponding to the average sound pressure value, the volume is reduced to zero. However, the volume may be halved, for example. A plurality of time threshold values may be provided to gradually reduce the volume.
The signal processing in FIG. 2 may be digitally processed or analog may be processed.
Further, in the embodiment, the state of over-listening is notified to the user by lighting the LED 19, but the user may be notified in various modes such as sounding of an alarm or notification by voice synthesis.

In the above-described embodiment, the following aspects are grasped from the viewpoint of preventing headphone deafness.

First, an adjustment unit that adjusts the volume of the input signal, a sounding body that produces sound based on the signal whose volume is adjusted by the adjusting unit, a microphone that collects the output sound of the sounding body, and a sound collection by the microphone. The sound pressure of the output sound produced by the sounding body is estimated based on the signal, and when the integrated value of the estimated sound pressure exceeds a predetermined threshold value, the adjusting unit is made to change the volume to a small value. A headphone characterized by having a volume changing unit for instructing is grasped. According to the above-mentioned headphones, the user can reduce the possibility of headphone deafness due to over-listening.

In the headphones, the volume changing unit has a conversion unit that converts the sound pick-up signal by the microphone into sound pressure, and a time threshold value in which the elapsed time from the start of use corresponds to the average value of the converted sound pressure. It may be configured to have a discriminating unit for determining whether or not the above is achieved, and instruct to change the volume to a small value when the elapsed time exceeds the time threshold value.

Further, the headphones may be configured to have a warning unit that outputs a predetermined warning when the integrated value of the sound pressure becomes equal to or higher than the threshold value. With this configuration, the user can know the state of listening too much.

1 ... Headphones, 3 ... Headband, 5L, 5R ... Headphone unit, 10 ... Ear pads, 12L, 12R ... Sounding body, 14L, 14R ... Microphone, 30 ... Adjustment unit, 40 ... Volume change unit, 42 ... Conversion unit, 44 … Discriminating part.

Claims (3)

An adjustment unit that adjusts the volume of the input signal,
A sounding body that produces a sound based on a signal whose volume has been adjusted by the adjusting unit, and
A microphone that collects the output sound from the sounding body, and
The sound pressure of the output sound produced by the sounding body is estimated based on the sound picked up signal by the microphone, and when the integrated value of the estimated sound pressure becomes equal to or higher than a predetermined threshold value, the volume is set to the adjusting unit. A volume change section that instructs you to make a small change,
Equipped with
The volume change section
A conversion unit that converts the sound pick-up signal from the microphone into sound pressure,
A discriminator that determines whether or not the elapsed time from the start of use is equal to or greater than the time threshold value corresponding to the average value of the converted sound pressure.
Have,
Headphones characterized in that when the elapsed time exceeds the time threshold value, an instruction is given to change the volume to a small value. The headphone according to claim 1 , further comprising a warning unit that outputs a predetermined warning when the integrated value of the sound pressure becomes equal to or higher than the threshold value. The volume change section
The headphone according to claim 1 or 2 , wherein if the average value of the sound pressure is equal to or higher than a predetermined value, the adjusting unit is instructed to change the volume to zero.

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