JP7255035B1 - sound equipment - Google Patents

Abstract

A sound device capable of outputting a sound that is easy to hear is provided. An acoustic device (10) includes a housing (20) having an internal space (21) and a signal processing section (40) having a function of amplifying high-frequency signals. Housing (20) comprises a vent (22) having one end (22a) and the other end (22b). One end (22a) of the vent (22) opens toward the outside of the housing (20), the other end (22b) is located inside the internal space (21), and the other end (22b) is provided with a partition (24). and communicates with the internal space (21) through a hole (25) formed in the partition (24). The housing (20) has a low resonant frequency and a high resonant frequency of this higher order as a resonator, and is configured such that the high resonant frequency is within the high frequency range. [Selection drawing] Fig. 1

Description

The present invention relates to acoustic devices.

Japanese Utility Model Registration No. 3165238 (hereinafter referred to as "Patent Document 1") describes a technique for amplifying the high frequency band, which is considered difficult for elderly people to hear, by about 15 dB compared to other frequency bands. A signal amplification section is described (particularly paragraph [0015] thereof). Elderly people can listen to the sound in which the treble range is supplemented by this treble signal amplifier (same paragraph [0017]). It is known that speech can be divided into fundamental frequency, vowel (excluding fundamental frequency), and consonant components (see, for example, paragraph [0025] of WO2009/110243).

Utility Model Registration No. 3165238

Persons with low hearing in the high frequency range (about 2 kHz to 4 kHz) within the audible range (the range of about 20 Hz to 20 kHz that humans can hear) have difficulty hearing consonants in the high range among speech components. Become. For this reason, it has been thought that hearing in the high frequency range can be compensated for by increasing the sound pressure level in the high frequency range using a high frequency signal amplifier (signal processing unit) as described in Patent Document 1. In other words, it has been thought that what is necessary is to make it easier to hear high-pitched sounds for which hearing is impaired.

An object of the present invention is to provide an acoustic device capable of outputting sounds that are easy to hear.

An acoustic device according to one solution means of the present invention includes a housing having an internal space and a speaker unit having a front portion and a rear portion. The acoustic device may include a signal processing section having a function of amplifying a signal in a predetermined frequency band. The housing may comprise a vent having one end and the other end. One end of the vent may open toward the outside of the housing, and the other end of the vent may be positioned within the internal space. The vent may have a partition at the other end of the vent. The vent may communicate with the interior space through a hole formed in the partition. The housing may have a low resonant frequency and this high-order high resonant frequency as a resonator. The housing may be configured such that the high resonant frequency is within the predetermined frequency band.

According to one solution means of the present invention, it is possible to provide an acoustic device capable of outputting a sound that is easy to hear.

1 is an explanatory diagram of an audio device according to an embodiment of the present invention; FIG. FIG. 2 is an explanatory diagram of an application example of the acoustic device shown in FIG. 1; 3 is an explanatory diagram of the configuration of the device shown in FIG. 2; FIG. FIG. 3 is an explanatory diagram of a main part of the apparatus shown in FIG. 2; 3 is another explanatory diagram of the main part of the apparatus shown in FIG. 2; FIG. 3 is another explanatory diagram of the main part of the apparatus shown in FIG. 2; FIG. FIG. 4 is an explanatory diagram of frequency characteristics of the acoustic device according to one embodiment of the present invention; FIG. 5 is an explanatory diagram of frequency characteristics of an acoustic device according to another embodiment of the present invention; FIG. 10 is an explanatory diagram of an audio device according to another embodiment of the present invention;

In the embodiments according to the present invention below, description will be divided into a plurality of sections when necessary, but in principle they are not unrelated to each other, and one part or all of the other may be modified, detailed, etc. in a relationship. For this reason, members having the same function are denoted by the same reference numerals in all the drawings, and repeated description thereof will be omitted. In addition, the number of components (including number, numerical value, amount, range, etc.) is limited to a specific number, unless otherwise specified or clearly limited to a specific number in principle. It may be more than or less than a certain number. In addition, when referring to the shape of a component, etc., it shall include things that are substantially similar to or similar to the shape, etc., unless otherwise specified or in principle clearly considered otherwise .

(First embodiment)
An embodiment according to the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram of the outline of the acoustic device according to the present embodiment, showing a state viewed from the side by cutting a predetermined portion. FIG. 2 is an explanatory diagram of an application example of the acoustic device, and shows a state viewed from the front. 3 is an explanatory diagram (block diagram) of the configuration of the acoustic device shown in FIG. 4 to 6 are explanatory diagrams of the main part (a part of the housing) of the acoustic device shown in FIG. is shown. FIG. 7 is an explanatory diagram of the frequency characteristics of the acoustic device according to this embodiment, with the horizontal axis representing frequency (Hz) and the vertical axis representing sound pressure level (dB).

As shown in FIG. 1, the acoustic device 10 includes a housing 20, a speaker unit 30, and a signal processing section 40. As shown in FIG. The housing 20 has an internal space 21 . In the case of the acoustic device 10 as a speaker, the housing 20 is called, for example, a speaker box or an enclosure. The signal processing unit 40 is configured, for example, on a circuit board, and is electrically connected to the speaker unit 30 by wiring (not shown). In this acoustic device 10, the signal from the signal processing section 40 can be output as sound from the speaker unit 30 attached to the housing 20. FIG.

The housing 20 has a vent 22 and has a bass reflex structure. The housing 20 is configured as a Helmholtz resonance resonator. From the speaker unit 30, a sound toward the front (outside the housing 20) and a sound toward the rear (inside the housing 20) are emitted at the same time. According to the bass reflex structure, the sound emitted from the rear of the speaker unit 30 can be taken out from the vent 22 to the front of the housing 20 through the internal space 21 of the housing 20 . Therefore, the sound from the vent 22 and the direct sound from the front of the speaker unit 30 are superimposed on the acoustic device 10, and the sound pressure level in the low range is reinforced. can be output.

The basic formula (1) of Helmholtz resonance is shown. where fn is the Helmholtz resonance frequency (Hz), c is the speed of sound (m/s), S is the cross-sectional area of the vent 22 (neck) (m ² ), L is the length of the vent 22 (m), and V is the housing is the volume (m ³ ) of the internal space 21 of the body 20; The acoustic device 10 can have a desired resonance frequency fn by adjusting the cross-sectional area S and length L of the vent 22 and the volume V of the internal space 21 to configure the housing 20 . For example, if the cross-sectional area S and the volume V are constant, the resonance frequency fn can be lowered by increasing the length L of the vent 22 . In general, the basic formula is corrected according to the shape of the vent 22 .

Vent 22 has one end 22a and the other end 22b. One end 22a of the vent 22 opens toward the outside of the housing 20 . Further, the other end 22b of the vent 22 is located inside the internal space 21. As shown in FIG. Also, the vent 22 has a partition 24 at the other end 22 b and communicates with the internal space 21 through a hole 25 formed in the partition 24 . FIG. 1 shows a vent 22 comprising a straight tubular length of hollow body (also called a "duct"). Such a housing 20 has a so-called bass reflex structure in which an internal space 21 communicates with the outside through a vent 22, and is configured as a resonator caused by Helmholtz resonance.

As will be described later, the housing 20 has a low resonance frequency and a higher resonance frequency as a resonator, and the high resonance frequency is within a predetermined sound range (high sound range) amplified by the signal processing unit 40. is configured to In the present embodiment, when manufacturing the acoustic device 10, the structure of the housing 20, particularly the structure of the vent 22 included in the housing 20, is adjusted based on the basic formula (1) of Helmholtz resonance. Specifically, a partition 24 is provided at the other end 22b of the vent 22, and the resonance frequency fn is adjusted by the shape, number, and arrangement of the openings (holes 25) of the partition 24. FIG.

The speaker unit 30 has a front portion 31 (also referred to as "front surface") and a rear portion 32 (also referred to as "back surface"). The speaker unit 30 is attached to the housing 20 with the front portion 31 facing the outside of the housing 20 and the rear portion 32 positioned within the internal space 21 . The speaker unit 30 is, for example, a dynamic type, and has a cone-shaped vibration member 33 and a driver 34 (transducer). The cone-shaped vibrating member 33 expands in diameter toward the outside of the housing 20 . A driver 34 moves its coil within a magnetic field due to current flowing through a voice coil (not shown). The speaker unit 30 can vibrate the vibrating member 33 with the driver 34 and output sound due to air vibration. It should be noted that the speaker unit 30 is generally attached to the housing 20 via a frame (not shown), for example.

A case where this acoustic device 10 is applied to a speaker 10A (acoustic device 10A) shown in FIG. 2 will be described. The speaker 10A has, for example, a function of receiving a signal transmitted by a transmitting device (not shown) and outputting it as sound, and a function of receiving AM radio/FM radio. The transmitting device is connected to, for example, an earphone terminal of a television, uses a frequency band of 2.4 GHz, and transmits a signal received from the television to the speaker 10A.

The speaker 10A includes a housing 20 and a speaker unit 30. As shown in FIG. The housing 20 is also a bass reflex structure resonator and has a vent 22 . The housing 20 includes an upper portion 20A, a middle portion 20B, and a lower portion 20C, which are assembled together. The speaker unit 30 has a grill 35 and a frame 36. - 特許庁The grille 35 is formed in a mesh shape so that sound from the speaker unit 30 can be output. The grill 35 can protect the vibrating member 33 and the like. Moreover, the frame 36 allows the speaker unit 30 to be easily attached to the housing 20 .

The speaker 10A also has a handle 50. As shown in FIG. A handle 50 is provided on the upper surface of the upper portion 20A. The handle 50 allows the user to easily carry the speaker 10A. The handle 50 has a projecting holder 50A. For example, by providing a holder 50A at the top of the arch-shaped handle 50, earphones or headphones can be hung.

The speaker 10A also has three buttons 51A, 51B, and 51C. These buttons 51 are provided on the upper surface of the upper portion 20A of the housing 20 . The button 51A is a switch for turning on or off the power (switching between "on" and "off"). The button 51B is a switch for slowing down the speed of conversation (switching between "slow" and "normal"). The button 51C is a switch for determining whether or not to amplify a signal in a predetermined frequency band (sound range) ("clear"/"normal" switching).

The speaker 10A also has a slider 52. As shown in FIG. The slider 52 is provided on the top surface of the upper portion 20A of the housing 20 . A slider 52 is a changeover switch for selecting the output of the speaker 10, and can select, for example, AM radio, FM radio or television. The speaker 10A also has two knobs 53A and 53B. The knob 53A is for adjusting the volume. The knob 53B is for adjusting the radio frequency. The speaker 10A also includes an antenna 54 for radio. Antenna 54 is provided on the upper surface of upper portion 20A of housing 20 .

The speaker 10A also includes an external connection section 55 having an AC adapter terminal and a headphone/earphone terminal. This external connection portion 55 is provided on the side surface of the lower portion 20</b>C of the housing 20 . The speaker 10A can be driven by power supply from a primary battery (for example, manganese dry battery) or a secondary battery (for example, lithium ion battery) provided inside the housing 20 in addition to direct power supply from an AC adapter. In addition, the speaker 10A includes a housing portion 56 (see FIG. 4, for example) recessed from the upper portion 20A of the housing 20 to the middle portion 20B. Small items such as a TV remote control and eyeglasses can be stored in the storage unit 56 .

As shown in FIG. 3, the speaker 10A includes a speaker unit 30, a receiver 37, and a signal processor . The receiver 37 has a function of receiving a signal from a transmitter or the like. The signal processing section 40 includes an amplification section 41 , a predetermined sound range amplification section 42 , and a speech speed conversion section 43 . The amplifier 41 (amplifier circuit) has a function of amplifying the entire range of the signal received by the receiver 37 .

The sound range amplifier 42 has a function of amplifying a predetermined sound range. The sound range amplifier 42, for example, so that the sound pressure (loudness) of the high frequency band (1.5 kHz to 6 kHz) is higher than the sound pressure of other frequency bands, a predetermined frequency (3 kHz) The sound pressure can be amplified around This high frequency band is a frequency band that is difficult for the elderly to hear, as described above, and corresponds to the consonant band. Therefore, it is possible to make it easier to hear the amplified voice in the predetermined sound range. Such a range amplifying unit 42 includes, for example, an equalizer (compensation circuit) having a bandpass filter and an amplifier circuit.

The speech speed converter 43 has a function of slowing down the speech speed without changing the pitch (pitch) of the sound. The speech speed conversion unit 43 can, for example, extend only the sounded sections of the voice so as to make the sound slow, and shorten (delete) the silent sections to some extent (to the degree that does not cause discomfort in terms of hearing). It is also possible to monitor the delay between the voice before conversion (original voice) and the voice after conversion. Therefore, by slowing down the speaking speed, it is possible to make it easier for elderly people, for example, who have difficulty hearing fast-spoken voices, to hear the voices. Such a speech speed conversion unit 43 is configured with, for example, a DSP (digital signal processor) circuit.

Here, the housing 20 of the bass reflex structure having the internal space 21 in the speaker 10A will be described more specifically. As shown in FIGS. 4 to 6, the central portion 20B forming the housing 20 has a tubular vent 22. As shown in FIG. 4 is a side view of the middle portion 20B cut along line IV-IV in FIG. FIG. 5 is a top view of the middle portion 20B cut along line VV in FIG. FIG. 6 is a diagram of the central portion 20B of FIG. 4 as viewed obliquely from the rear.

Vent 22 has one end 22a and the other end 22b. One end 22a of the vent 22 opens toward the outside of the housing 20 (middle portion 20B), and the other end 22b is located inside the internal space 21 . Also, the vent 22 has a partition 24 at the other end 22b. Also, the vent 22 communicates with the internal space 21 through a hole 25 formed in the partition 24 .

Also, the vent 22 has an inner diameter that expands (diameter expansion) from the other end 22b toward the one end 22a. In this way, by forming the vent 22 into a shape with an enlarged diameter (flared shape), it is possible to reduce the generation of abnormal noise caused by the air discharged from the internal space 21 to the outside through the vent 22 . One end 22a of the vent 22 is chamfered in an R shape, but as shown in FIG. It is larger than the curvature radius Rf of the edge remote from the front portion 31) side. This makes it easier for the sound from the vent 22 to spread to the speaker unit 30 side. Therefore, in the speaker 10A, the sound from the vent 22 and the direct sound from the front of the speaker unit 30 overlap more, so that the sound pressure level in the low range is reinforced, and the sound that is easy to hear is output. be able to.

Further, in the speaker 10A, five holes 25 are formed in the partition 24 (see FIG. 2). One of the holes 25 (25c) is formed on the central axis of the tubular vent 22, that is, at the center of the end face (specifically, the partition 24) of the other end 22b. The remaining four holes 25 (25s) are formed around the central axis, that is, around the center of the end surface of the other end 22b at regular intervals. In this manner, the resonance frequency caused by the housing 20 having a bass reflex structure can be adjusted by adjusting the number (one or more) and arrangement of the holes 25 formed in the partition 24 at the other end 22b of the vent 22. FIG.

The frequency characteristics of the speaker 10A including the housing 20 having the bass reflex structure will be described with reference to FIG. FIG. 7 shows a curve C1 when the button 51C is on (“clear” state in which the high frequency signal is amplified), a curve C2 when the button 51C is off (“normal” state), and the housing 20. is shown as curve C3 in a closed configuration (where vent 22 is completely blocked).

Comparing the curves C1 and C2 of the bass reflex structure and the curve C3 of the closed structure, the sound pressure increases around the resonance frequencies near 120 Hz, 480 Hz, and 1920 Hz. That is, the bass reflex structure of this embodiment generates a primary resonance frequency (low resonance frequency) at 120 Hz, a secondary resonance frequency (middle resonance frequency) at 480 Hz, and a tertiary resonance frequency (high resonance frequency) at 1920 Hz. there is

By the way, it is known that speech can be divided into fundamental frequency, vowel and consonant components. The fundamental frequency represents the pitch (height) of a human voice, and is distributed in a range (low range) around 120 Hz to 325 Hz. For example, the fundamental frequencies are distributed in the range of 120 Hz to 250 Hz for males and in the range of 210 Hz to 325 Hz for females. Vowel frequencies are widely distributed around 250 Hz to 650 Hz (middle range), and consonant frequencies are distributed over 1500 Hz (high range).

In such a sound distribution, by using a signal amplifier (electronic circuit), the sound pressure signal of the high range (consonants), which is difficult for the elderly to hear, is reduced from the sound pressure of other ranges. It has been considered effective to amplify (reinforce) also (see Patent Document 1). In the speaker 10A of the present embodiment, due to the structure of the housing 20, in addition to the high range (consonant) due to the high resonance frequency, the sound pressure of the low range (fundamental frequency) due to the low resonance frequency is amplified (sound is composed). By sharpening the high and low ranges, an easy-to-listen sound is output (curves C1 and C2 relative to curve C3). That is, the housing 20 of the speaker 10A is configured as a resonator to have a low resonance frequency and this high-order high resonance frequency, and furthermore, is configured so that this high resonance frequency is within the treble range.

In addition, the speaker 10A amplifies the sound pressure of the middle range (vowels) by the medium resonance frequency (480 Hz) between the low resonance frequency (120 Hz) and the high resonance frequency (1920 Hz), thereby producing a more audible voice. output (curves C1, C2 against curve C3). That is, the housing 20 of the speaker 10A is configured to have a primary resonance frequency (low resonance frequency), a secondary resonance frequency (middle resonance frequency), and a tertiary resonance frequency (high resonance frequency).

In addition, in the speaker 10A, by increasing the sound pressure signal in the high frequency band (high range) of 1.5 kHz to 6 kHz by the signal processing unit 40, a more audible sound is output (the curve C1). That is, the speaker 10A is provided with the signal processing section 40 having a function of amplifying the audio signal in the high-frequency band in the high-pitched range, thereby outputting a more audible sound.

(Second embodiment)
In the first embodiment, a low resonance frequency (primary resonance), a middle resonance frequency (secondary resonance) in the midrange, and a high resonance frequency (tertiary resonance) in the high range have been described. In this embodiment, a case in which a low resonance frequency (primary resonance) is generated in a low frequency range and a high resonance frequency (secondary resonance) in a high frequency range will be described with reference to the drawings. FIG. 8 is an explanatory diagram of the frequency characteristics of the acoustic device according to the present embodiment, with the horizontal axis representing frequency (Hz) and the vertical axis representing sound pressure level (dB). FIG. 9 is an explanatory diagram of the outline of the acoustic device according to the present embodiment, showing a state viewed from the side by cutting a predetermined portion.

FIG. 8 shows the curve C4 of the bass reflex structure of this embodiment and the curve C5 of the closed structure of the comparative example (with the vents of the bass reflex structure completely closed). In the curve C4 of the bass reflex structure, the sound pressure increases around the resonance frequencies near 120 Hz and 3 kHz as compared to the curve C5 of the closed structure. That is, the bass reflex structure of this embodiment generates a primary resonance frequency (low resonance frequency) at 120 Hz and a secondary resonance frequency (high resonance frequency) at 3 kHz. A method of manufacturing such an acoustic device having a bass reflex structure can be adjusted by the structure of the vent based on the basic formula (1) of Helmholtz resonance.

For example, FIG. 9 shows an acoustic device 110 with a housing 120 having a vent 122 with a different structure than the vent 22 of the first embodiment. Specifically, housing 120 includes a vent 122 having one end 122a and another end 122b. One end 122a of the vent 122 opens toward the outside of the housing 120, the other end 122b is located inside the internal space 121 of the housing 120, and the other end 122b has a partition 124. As shown in FIG.

Housing 120 also includes a tubular body 126 having one end 126a and another end 126b. The tubular body 126 has a cross-sectional area (end area) of one end 126a smaller than that of the other end 122b of the vent 122, the end 126a opening toward the vent 122 through the partition 124, and the other end 126b. is open and located in the internal space 121 .

One end 126 a of the tubular body 126 can be said to open toward the vent 122 through a hole formed in the partition 124 . Also, in this embodiment, the vent 122 and the tubular body 126 are explained separately, but since both the vent 122 and the tubular body 126 have the function of a vent (duct, port) in the bass reflex structure, they can be regarded as a vent as a whole. can also

The method of manufacturing the acoustic device 110 having such a bass reflex structure is based on the basic formula (1) of Helmholtz resonance, and after adjusting the structure of the vent 122, further, the shape (length, thickness) of the tubular body 126, Depending on the number and arrangement, it is possible to make it easier to adjust the resonance frequency caused by the housing 120 having the bass reflex structure.

Although the present invention has been specifically described above based on the embodiments, it goes without saying that the present invention is not limited to the above-described embodiments, and can be variously modified without departing from the scope of the invention.

In the above embodiment, when using a case with a bass reflex structure as a resonator in which a high-order high resonance frequency of a low resonance frequency is within a predetermined sound range (for example, a high frequency band of 1.5 kHz to 6 kHz) explained. Without being limited to this, a housing having a low resonance frequency at least within the fundamental frequency band (100 Hz to 250 Hz) of sound may be used. Even if the sound pressure level of the fundamental frequency band (bass band) is only reinforced, it is possible to output sound that is easy to hear.

In the above embodiment, the case where the audio device includes the signal processing unit has been described. Not limited to this, a signal from an external signal processing unit may be transmitted to the audio device by wire or wirelessly, and output as sound from the speaker unit.

In the above embodiment, the case of using a vent as a baffle structure that causes Helmholtz resonance has been described. The vent includes a thick plate or the like with a hole (also called a "port").

In the above embodiment, the case of using a dynamic speaker unit has been described. Not limited to this, a capacitor type, an excitation type, or the like may also be used. Also, the case of using a cone-shaped vibration member for the speaker unit has been described. Not limited to this, a dome shape, a horn shape, or the like may be used.

10: Acoustic device, 20: Housing, 21: Internal space, 22: Vent, 22a: One end, 22b: Other end, 24: Partition, 25: Hole.

Claims (5)

An acoustic device comprising a housing having an internal space, a speaker unit having a front portion and a rear portion, and a signal processing section having a function of amplifying a signal in a predetermined frequency band,
the speaker unit is attached to the housing with the front portion facing the outside of the housing and the rear portion positioned within the internal space;
the housing comprises a vent having one end and the other end;
One end of the vent opens toward the outside of the housing, the other end of the vent is positioned in the internal space, and the other end of the vent has a partition formed in the partition. The vent communicates with the internal space through a hole, the peripheral edge portion of one end of the vent is chamfered in an R shape, and the radius of curvature of the edge portion closer to the front side is larger than the radius of curvature of the edge portion farther from the front side,
The housing has a low resonance frequency and a high-order high resonance frequency as a resonator, and is configured such that the high resonance frequency is within the predetermined frequency band.
An acoustic device characterized by: the housing is configured to have an intermediate resonant frequency between the low resonant frequency and the high resonant frequency;
The acoustic device according to claim 1. the housing comprises a tubular body having one end and the other end;
One end of the tubular body opens toward the vent through the hole, and the other end of the tubular body opens and is positioned within the internal space.
The acoustic device according to claim 1. An acoustic device comprising a housing having an internal space and a speaker unit having a front portion and a rear portion,
the speaker unit is attached to the housing with the front portion facing the outside of the housing and the rear portion positioned within the internal space;
the housing comprises a vent having one end and the other end;
One end of the vent opens toward the outside of the housing, the other end of the vent is positioned in the internal space, and the other end of the vent has a partition formed in the partition. The vent communicates with the internal space through a hole, the peripheral edge of one end of the vent is chamfered in an R shape, and the radius of curvature of the edge closer to the front side is larger than the radius of curvature of the edge farther from the front side.
An acoustic device characterized by: An acoustic device comprising a housing having an internal space and a speaker unit having a front portion and a rear portion,
the speaker unit is attached to the housing with the front portion facing the outside of the housing and the rear portion positioned within the internal space;
the housing comprises a vent and a tubular body having one end and the other end, respectively;
One end of the vent opens toward the outside of the housing, the other end of the vent is located in the internal space, the other end of the vent has a partition, and the one end of the vent has a peripheral edge. The portion is chamfered in an R shape, and the radius of curvature of the edge closer to the front side is larger than the radius of curvature of the edge farther from the front side,
The tubular body has an area of one end smaller than an area of the other end of the vent, one end of the tubular body opens toward the vent through the partition, and the other end of the tubular body opens. located within the interior space;
An acoustic device characterized by:

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