JP7423836B1 - sound equipment - Google Patents

Abstract

An object of the present invention is to provide an audio device that can output easy-to-listen sounds. An acoustic device (10) includes a casing (20) having an internal space (21) and a signal processing section (40) having a function of amplifying high-frequency signals. The housing (20) includes a vent (22) having one end (22a) and another end (22b). The vent (22) has one end (22a) open toward the outside of the housing (20), the other end (22b) located inside the internal space (21), and the other end (22b) provided with a partition (24). It communicates with the internal space (21) through a hole (25) formed in the partition (24). The housing (20) is configured as a resonator to have a low resonant frequency and a higher-order high resonant frequency, with the high resonant frequency being within the treble range. [Selection diagram] Figure 1

Description

The present invention relates to an audio device.

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

Utility model registration No. 3165238

People who have poor hearing in the high frequency range (frequency range of 2kHz to 4kHz) within the audible range (range of about 20Hz to 20kHz that humans can hear) have difficulty hearing consonants in the high frequency range of voice 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 amplification unit (signal processing unit) as described in Patent Document 1. In other words, it has been thought that all that is needed is to make it easier to hear high-pitched sounds where hearing ability has deteriorated.

One object of the present invention is to provide an audio device that can output easy-to-listen sounds.

An audio device according to one solution of the present invention includes a housing having an internal space and a speaker unit having a front part and a rear part. The audio device may include a signal processing section having a function of amplifying a signal in a predetermined frequency band. The housing may include a vent having one end and an opposite end. One end of the vent may be open toward the outside of the housing, and the other end of the vent may be located 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 a higher-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 of the present invention, it is possible to provide an audio device that can output easy-to-listen sounds.

FIG. 1 is an explanatory diagram of an acoustic device according to an embodiment of the present invention. FIG. 2 is an explanatory diagram of an example of application of the acoustic device shown in FIG. 1; 3 is an explanatory diagram of the configuration of the apparatus shown in FIG. 2. FIG. 3 is an explanatory diagram of a main part of the apparatus shown in FIG. 2. FIG. FIG. 3 is another explanatory diagram of the main parts of the device shown in FIG. 2; FIG. 3 is another explanatory diagram of the main parts of the device shown in FIG. 2; FIG. 2 is an explanatory diagram of frequency characteristics of an audio device according to an embodiment of the present invention. FIG. 7 is an explanatory diagram of frequency characteristics of an audio device according to another embodiment of the present invention. FIG. 3 is an explanatory diagram of an acoustic device according to another embodiment of the present invention.

The following embodiments of the present invention will be explained in multiple sections if necessary, but in principle, they are not unrelated to each other, and one may include variations, details, etc. of some or all of the other. In a relationship. Therefore, in all the figures, members having the same functions are designated by the same reference numerals, and repeated explanations thereof will be omitted. Furthermore, the number of constituent elements (including numbers, numerical values, amounts, ranges, etc.) shall not be limited to a specific number unless otherwise specified or in principle clearly limited to a specific number. The number may be greater than or less than a specific number. Furthermore, when referring to the shape of a component, etc., it shall include anything that substantially approximates or resembles that shape, etc., unless specifically specified or if it is clearly considered otherwise in principle. .

(First embodiment)
Embodiments according to the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram of the outline of the audio device according to the present embodiment, and shows a state where a predetermined portion is cut and viewed from the side. FIG. 2 is an explanatory diagram of an application example of the acoustic device, and is shown as viewed from the front. Further, FIG. 3 is an explanatory diagram (block diagram) of the configuration of the audio device shown in FIG. 2. Furthermore, FIGS. 4 to 6 are explanatory diagrams of the main parts (part of the housing) of the audio device shown in FIG. It shows. Further, FIG. 7 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).

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

The housing 20 includes a vent 22 and has a bass reflex structure. The housing 20 is configured as a Helmholtz resonance resonator. The speaker unit 30 emits sound directed toward the front (outside of the housing 20) and at the same time, sound directed toward the rear (inside the housing 20). According to the bass reflex structure, sound emitted from the rear of the speaker unit 30 can be extracted from the vent 22 to the front of the housing 20 through the internal space 21 of the housing 20. Therefore, in the acoustic device 10, by superimposing the sound from the vent 22 and the direct sound from the front of the speaker unit 30, the sound pressure level in the bass range in particular is reinforced, and as described later, the sound is easy to hear. can be output.

The basic formula (1) of Helmholtz resonance is shown. Here, 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 casing. It 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, when the cross-sectional area S and the volume V are constant, the resonant frequency fn can be lowered by increasing the length L of the vent 22. Note that, in general, the basic equation is corrected depending on the shape of the vent 22.

The vent 22 has one end 22a and the other end 22b. One end 22a of the vent 22 is open toward the outside of the housing 20. Further, the other end 22b of the vent 22 is located within the internal space 21. Further, the vent 22 has a partition 24 at the other end 22b, and communicates with the internal space 21 through a hole 25 formed in the partition 24. In FIG. 1, a vent 22 is shown that is comprised of a hollow body (also referred to as a "duct") having a straight tubular length. 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 due to Helmholtz resonance.

As will be described later, the housing 20 serves as a resonator and has a low resonant frequency and a higher-order high resonant frequency, and the housing 20 is designed so that the high resonant frequency is within a predetermined sound range (treble range) that is amplified by the signal processing unit 40. It is composed of In the present embodiment, when manufacturing the acoustic device 10, the structure of the casing 20, particularly the structure of the vent 22 included in the casing 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.

The speaker unit 30 has a front portion 31 (also referred to as “front”) and a rear portion 32 (also referred to as “back”). The speaker unit 30 is attached to the housing 20 with the front part 31 facing outside of the housing 20 and the rear part 32 located within the internal space 21. The speaker unit 30 is, for example, a dynamic type, and includes a cone-shaped vibration member 33 and a driver 34 (transducer). The cone-shaped vibrating member 33 has a diameter increasing toward the outside of the housing 20. The driver 34 has a voice coil (not shown) that moves within a magnetic field due to a current flowing through the coil. The speaker unit 30 can vibrate the vibration member 33 using the driver 34 and output sound due to air vibration. Note 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. Note that the transmitting device is connected to, for example, an earphone terminal of a television, and transmits a signal taken in from the television to the speaker 10A using a frequency band of 2.4 GHz.

The speaker 10A includes a housing 20 and a speaker unit 30. The housing 20 is also a resonator with a bass reflex structure 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 includes a grill 35 and a frame 36. The grill 35 is formed in a mesh shape so that the sound from the speaker unit 30 can be output. According to the grille 35, the vibrating member 33 and the like can be protected. Further, according to the frame 36, the speaker unit 30 can be easily attached to the housing 20.

Further, the speaker 10A includes a handle 50. The 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 protruding holder 50A. For example, by providing a holder 50A at the top of the arched handle 50, earphones or headphones can be hung.

Further, the speaker 10A includes 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 turning off the power (switching between "on" and "off"). The button 51B is a switch for determining whether or not to slow down the conversation speed (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) (switching between "clear" and "normal").

Further, the speaker 10A includes a slider 52. The slider 52 is provided on the upper surface of the upper portion 20A of the housing 20. The slider 52 is a changeover switch for selecting the output of the speaker 10, and can select AM radio, FM radio, or television, for example. Further, the speaker 10A includes 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 a radio antenna 54. The antenna 54 is provided on the upper surface of the upper portion 20A of the 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 20C of the housing 20. The speaker 10A can be driven not only by direct power supply from an AC adapter but also by power supply from a primary battery (for example, a manganese dry battery) or a secondary battery (for example, a lithium ion battery) provided inside the housing 20. Further, the speaker 10A includes a housing portion 56 (for example, see FIG. 4) that is recessed from the upper portion 20A of the housing 20 to the middle portion 20B. This storage section 56 can store small items such as a television remote control and glasses, for example.

As shown in FIG. 3, the speaker 10A includes a speaker unit 30, a receiving section 37, and a signal processing section 40. The receiving unit 37 has a function of receiving signals from a transmitting device 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 amplifying section 41 (amplifying circuit) has a function of amplifying the entire sound range of the signal received by the receiving section 37.

The sound range amplifying section 42 has a function of amplifying a predetermined sound range. For example, the sound range amplification unit 42 adjusts the frequency to a predetermined frequency (3kHz) so that the sound pressure (loudness) of the high frequency band (1.5kHz to 6kHz) is higher than the sound pressure of other frequency bands. It is possible to amplify the sound pressure centered on . As mentioned above, this high frequency band is a frequency band that is difficult for elderly people to hear, and corresponds to the consonant band. Therefore, it is possible to easily hear amplified sounds in a predetermined range. Such a range amplification section 42 is configured to include, for example, an equalizer (compensation circuit) having a bandpass filter and an amplification 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 converter 43 can, for example, extend only the voiced sections of the voice so that they become slow voices, and shorten (delete) the silent sections to a certain extent (to an extent that does not give an audible sense of discomfort). It is also possible to monitor the delay between the voice before conversion (original voice) and the voice after return. Therefore, by slowing down the speaking speed, it is possible to make the voice easier to hear, for example, for elderly people who find it difficult to hear voices that speak quickly. Such speech speed converter 43 is configured to include, for example, a DSP (digital signal processor) circuit.

Here, the bass reflex structure housing 20 having the internal space 21 in the speaker 10A will be described in more detail. As shown in FIGS. 4 to 6, the middle portion 20B of the housing 20 has a tubular vent 22. As shown in FIGS. Note that FIG. 4 is a side view of the middle portion 20B taken along line IV-IV in FIG. FIG. 5 is a view of the middle portion 20B taken along line VV in FIG. 4, viewed from above. FIG. 6 is a diagram of the middle portion 20B of FIG. 4 viewed diagonally from the rear.

The vent 22 has one end 22a and the other end 22b. The vent 22 has one end 22a opening toward the outside of the housing 20 (middle portion 20B), and the other end 22b located within the internal space 21. Further, the vent 22 has a partition 24 at the other end 22b. Further, the vent 22 communicates with the internal space 21 through a hole 25 formed in the partition 24.

Further, the inner diameter of the vent 22 increases (increases in diameter) 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 (flare shape), it is possible to reduce the generation of abnormal noise due to air discharged from the internal space 21 through the vent 22 to the outside. In addition, the vent 22 has an R-shaped peripheral edge at one end 22a, but as shown in FIG. It is larger than the radius of curvature Rf of the edge farthest from the front part 31) side. This makes it easier for the sound from the vent 22 to spread toward 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 bass range in particular is reinforced, and an easy-to-listen sound is output. be able to.

Furthermore, 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 surface of the other end 22b (specifically, the partition 24). The remaining four holes 25 (25s) are formed at equal intervals around the central axis, that is, around the center of the end surface of the other end 22b. In this way, the resonance frequency caused by the bass reflex housing 20 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.

With reference to FIG. 7, the frequency characteristics of the speaker 10A including the casing 20 having a bass reflex structure will be described. FIG. 7 shows a curve C1 when the button 51C is in the on state (a "clear" state in which high-frequency signals are amplified), a curve C2 when the button 51C is in an off state (a "normal" state), and a curve C2 when the button 51C is in an off state (a "normal" state). A curve C3 for a closed structure (a state in which the vent 22 is completely closed) is shown.

Comparing the curves C1 and C2 of the bass reflex structure with the curve C3 of the closed structure, the sound pressure increases around each of the resonant frequencies around 120 Hz, around 480 Hz, and around 1920 Hz. That is, the bass reflex structure of this embodiment generates a first-order resonance frequency (low resonance frequency) at 120Hz, a second-order resonance frequency (medium resonance frequency) at 480Hz, and a third-order resonance frequency (high resonance frequency) at 1920Hz. There is.

In such a voice distribution, by using a signal amplification section (electronic circuit), the sound pressure signals of high-pitched sounds (consonants), which are difficult for elderly people to hear, can be made higher than the sound pressure of other sound ranges. It has been considered effective to also amplify (reinforce) (see Patent Document 1). In the speaker 10A of this embodiment, due to the structure of the housing 20, in addition to the high sound range (consonants) due to high resonance frequency, the sound pressure of low sound range (fundamental frequency) due to low resonance frequency is increased , making it easier to listen. Easy speech 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 resonant frequency and a higher-order high resonant frequency, and further configured such that the high resonant frequency is within a treble range.

In addition, in the speaker 10A, due to the structure of the housing 20, the sound pressure of the middle range (vowel) due to the middle resonance frequency (480Hz) between the low resonance frequency (120Hz) and the high resonance frequency (1920Hz) is increased. , outputs audio that is easier to hear (curves C1 and C2 relative to curve C3). That is, the housing 20 of the speaker 10A is configured to have a primary resonant frequency (low resonant frequency), a secondary resonant frequency (middle resonant frequency), and a tertiary resonant frequency (high resonant frequency).

In addition, in the speaker 10A, by amplifying the sound pressure of the middle range (vowels) due to the middle resonance frequency (480Hz) between the low resonance frequency (120Hz) and the high resonance frequency (1920Hz), it is possible to make the sound easier to hear. It is outputting (curves C1 and C2 for curve C3). That is, the housing 20 of the speaker 10A is configured to have a primary resonant frequency (low resonant frequency), a secondary resonant frequency (middle resonant frequency), and a tertiary resonant frequency (high resonant frequency).

In addition, in the speaker 10A, by increasing the sound pressure signal in the high frequency band (treble range) of 1.5 kHz to 6 kHz by the signal processing unit 40, the speaker 10A outputs a sound that is easier to hear (as shown in the curve with respect to the curve C2). C1). That is, the speaker 10A is equipped with the signal processing section 40 having a function of amplifying the audio signal in the high frequency band in the treble range, thereby making it possible to output audio that is easier to listen to.

(Second embodiment)
In the first embodiment, a case has been described in which a low resonant frequency (primary resonance) is generated in the bass range, a medium resonant frequency (secondary resonance) is generated in the middle range, and a high resonant frequency (tertiary resonance) is generated in the high range. In this embodiment, a case where a low resonant frequency (primary resonance) is generated in the bass range and a high resonant frequency (secondary resonance) is generated in the treble 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 this 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 audio device according to the present embodiment, showing a state where a predetermined portion is cut and viewed from the side.

FIG. 8 shows a curve C4 of the bass reflex structure of the present embodiment and a curve C5 of the closed structure of the comparative example (the vent of the bass reflex structure is completely closed). In the curve C4 of the bass reflex structure, the sound pressure increases around the resonance frequencies of around 120 Hz and around 3 kHz, compared to the curve C5 of the closed structure. That is, the bass reflex structure of this embodiment generates a first-order resonance frequency (low resonance frequency) at 120 Hz and a second-order resonance frequency (high resonance frequency) at 3 kHz. The manufacturing method of such a bass reflex acoustic device is based on the basic equation (1) of Helmholtz resonance, and can be adjusted by adjusting the vent structure.

For example, FIG. 9 shows an acoustic device 110 including a housing 120 having a vent 122 having a structure different from the vent 22 of the first embodiment. Specifically, the housing 120 includes a vent 122 having one end 122a and the other end 122b. The vent 122 has one end 122a opening toward the outside of the housing 120, the other end 122b located within the internal space 121 of the housing 120, and the other end 122b having a partition 124.

Furthermore, the housing 120 includes a tubular body 126 having one end 126a and the other end 126b. The tubular body 126 has a cross-sectional area (end area) at one end 126a smaller than a cross-sectional area (end area) at the other end 122b of the vent 122, one end 126a opens to the vent 122 side via the partition 124, and the other end 126b is open and located in the internal space 121.

Note that the tubular body 126 can also be said to have one end 126a open toward the vent 122 through a hole formed in the partition 124. Further, 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 a bass reflex structure, they can be regarded as a vent as a whole. You can also do it.

The manufacturing method of the acoustic device 110 having such a bass reflex structure is based on the basic equation (1) of Helmholtz resonance, and after adjusting the structure of the vent 122, the shape (length, thickness) of the tubular body 126, Depending on the number and arrangement, it is possible to more easily adjust the resonant frequency caused by the casing 120 having a 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 embodiments and can be modified in various ways without departing from the gist thereof.

In the above embodiment, when a case with a bass reflex structure is used as a resonator in which a high-order high-order resonance frequency of the low resonance frequency is within a predetermined sound range (for example, a high frequency band of 1.5 kHz to 6 kHz). explained. The present invention is not limited to this, and a housing having a low resonance frequency at least within the fundamental frequency band (100 Hz to 250 Hz) of audio may be used. It is possible to output a sound that is easy to hear simply by reinforcing the sound pressure level in the fundamental frequency band (bass band).

In the embodiment, the case where the audio device includes the signal processing section has been described. However, the present invention is not limited to this, and a signal from an external signal processing section may be transmitted to the audio device by wire or wirelessly, and output as audio from the speaker unit.

In the embodiment described above, a case has been described in which a vent is used as a buff-lev structure that causes Helmholtz resonance. This vent also includes a hole (also called a "port") made in a thick plate or the like.

In the embodiment described above, a case was described in which a dynamic type speaker unit was used. The present invention is not limited to this, and a capacitor type, an excitation type, etc. may also be used. Furthermore, a case has been described in which a cone-shaped vibration member is used as the vibration member of the speaker unit. The shape is not limited to this, and 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 audio device comprising a housing having an internal space, a speaker unit having a front part and a rear part, and a signal processing section having a function of amplifying a signal in a predetermined frequency band with a peak,
The speaker unit is attached to the housing with the front portion facing outside the housing and the rear portion located within the internal space,
The housing includes a vent having one end and an opposite end,
The vent has one end thereof open toward the outside of the casing, the other end of the vent located within the internal space, and a partition formed at the other end of the vent. communicating with the interior space through a hole;
The housing has a first-order low resonant frequency and a higher-order high resonant frequency as a resonator, the low resonant frequency is within the fundamental frequency band of audio, and the high resonant frequency is within the predetermined frequency band. and is configured such that the sound pressure at the high resonant frequency is higher than the sound pressure at the low resonant frequency,
The increase in the sound pressure of the frequency characteristic from when the signal processing section is not activated to when it is activated is such that the increase in the sound pressure at the peak is larger than the increase in the sound pressure at the low resonance frequency.
A sound device characterized by: An audio device comprising a housing having an internal space, a speaker unit having a front part and a rear part, and a signal processing section having a function of amplifying a signal in a predetermined frequency band with a peak,
The speaker unit is attached to the housing with the front portion facing outside the housing and the rear portion located within the internal space,
The housing includes a vent having one end and an opposite end,
The vent has one end thereof open toward the outside of the housing, the other end of the vent located within the internal space, and a partition formed at the other end of the vent. communicating with the interior space through a hole;
The housing has a first-order low resonant frequency and a first-order high resonant frequency as a resonator, the low resonant frequency is within a 100 to 325 Hz band, and the high resonant frequency is It is configured to be within the frequency band that is amplified above .5kHz,
The increase in the sound pressure of the frequency characteristic when the signal processing section is activated from when it is not activated is larger than the increase in the sound pressure at the low resonance frequency. The increase is large,
A sound device characterized by: An acoustic device comprising a speaker unit, a casing with a buffleaf structure in which the speaker unit is provided, and a signal processing section having a function of amplifying a signal in a predetermined frequency band with a peak,
The housing has a first-order low resonant frequency and a higher-order high resonant frequency, the low resonant frequency is within the fundamental frequency band of audio, and the high resonant frequency is within the predetermined frequency band. It is configured as follows.
The increase in the sound pressure of the frequency characteristic from when the signal processing section is not activated to when it is activated is such that the increase in the sound pressure at the peak is larger than the increase in the sound pressure at the low resonance frequency.
A sound device characterized by: speaker unit,
The speaker unit is provided with a bass reflex structure housing having a first-order low resonance frequency and a higher-order high resonance frequency,
The housing is configured such that the low resonant frequency is within a fundamental frequency band of speech, and the high resonant frequency is within a consonant frequency band higher than the fundamental frequency band,
outputting an amplified signal having a peak in the consonant frequency band as audio so that the increase in sound pressure in the consonant frequency band is larger than the increase in sound pressure in the fundamental frequency band;
A sound device characterized by: comprising a signal processing unit having a function of amplifying the signal in the consonant frequency band;
The acoustic device according to claim 4.

Images