JP2018137682A - Dummy head and ear plug - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dummy head which emits sounds to the outside while inhibiting alteration, and to provide an ear plug attached to the dummy head.SOLUTION: A dummy head 1 includes: a housing 2 in which a space 20 is formed; and a speaker 3 which is disposed in the space 20 and generates sound waves by vibrating a diaphragm 31. The housing 2 is formed with a lip opening 25a allowing communication between the exterior of the housing 2 and the space 20. The speaker 3 is disposed so as to cover at least part of the lip opening 25a from the space 20 side and forms a gap between a peripheral edge part of the speaker 3 and an inner surface 20a of the housing 2. A dimension L of the gap ranges 1 mm to 10 mm at a maximum.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a dummy head and earplugs that emit sound to the outside.

  The human ear perceives sound by receiving sound waves that are diffracted and reflected in a complex manner by the pinna. If a sound wave affected by such a pinna is received by a microphone, recorded as it is, and reproduced, a sound with a more three-dimensional effect can be perceived by the listener. That is, it is possible to make the listener feel when listening to a sound close to the original sound.

  Recording / playback reflecting the influence of the pinna or the like is called binaural recording / playback, and is performed using, for example, a dummy head described in Patent Document 1. The dummy head has a housing simulating a human head, and a projection simulating the auricle and a passage simulating the external auditory canal are formed in the housing. In addition, an ear simulator having a microphone is disposed in a portion corresponding to a human inner ear.

  Such a dummy head receives a sound wave that has been diffracted / reflected by a housing or a projection and passed through a passage with an ear simulator, and thus a head according to an actual human head (hereinafter also referred to as “real head”). Head-related transfer function (HRTF) can be measured. Binaural recording can be performed by convolving the head-related transfer function or a head-related impulse response (HRIR) obtained by inverse Fourier transform of the head-related transfer function with a signal.

JP-A-5-153687

  By providing a speaker, the dummy head can have not only a head-related transfer function and head impulse response measurement function but also a speech function. In the dummy head, a speaker is disposed inside the housing, and an opening is formed in a portion corresponding to the lip of the housing. When the speaker generates sound waves, the sound waves are emitted to the outside through the opening.

  Most of the dummy heads equipped with the above-described speakers emit test sound such as a sine wave of a specific frequency. On the other hand, the inventor of the present application has researched and developed a dummy head that spontaneously utters from the opening simultaneously with sound collection and detects the utterance in a portion corresponding to a human inner ear. Because such a dummy head utters naturally with a voice close to the real head, it is mounted on a robot, performance evaluation of a mobile phone considering the influence of self-speech during a user's call, development of a hearing aid, auditory research, etc. Application to various purposes can be expected.

  However, the size of the opening that can be formed in the housing is extremely narrow, about 20 mm × 40 mm, which is equivalent to a human lip. For this reason, the inventor of the present application cannot transmit sound waves through a narrow opening and repeats reflection in the space inside the housing, or multiple sound waves are reflected between the speaker and the inner surface of the housing, resulting in sound quality. I faced the challenge of changing. As a result, the sound perceived by the listener is greatly different from the original sound.

  As a solution to the above problem, an approach to increase the size of the opening is conceivable in order to efficiently pass sound waves. However, a new problem arises that the opening becomes unnaturally larger than that of an actual human lip, impairing the design, and the position where sound waves are emitted is different from that of the human lip.

  The present invention has been made in view of such a problem, and an object thereof is to provide a dummy head capable of emitting sound to the outside while suppressing deterioration, and an earplug attached to the dummy head. .

  One aspect of the present invention for solving the above-described problems is a dummy head that emits sound to the outside, a housing having a space formed therein, and a sound wave generated by vibrating the diaphragm disposed in the space. And a speaker to be generated. The casing is formed with a lip opening that allows communication between the outside of the casing and the space. The speaker is arranged so as to cover at least a part of the lip opening from the space side and to form a gap between the peripheral edge of the speaker and the inner side surface of the housing. The size of the gap is 1 mm or more and 10 mm or less at the maximum.

  According to this configuration, since the speaker is arranged so as to cover at least a part of the lip opening from the space side, at least a part of the sound wave generated by the speaker is directly emitted to the outside through the lip opening. The The remaining portion that cannot pass directly through the lip opening is reflected by a space formed between the inner surface of the casing around the lip opening and the diaphragm of the speaker.

  Therefore, in the above configuration, a gap is further formed between the peripheral portion of the speaker and the inner side surface of the housing. For this reason, the sound wave reflected in the space formed between the inner side surface of the casing around the lip opening and the diaphragm of the speaker passes through the gap and is emitted to the outside of the space. That is, multiple reflections of sound waves in the space can be reduced, and the sound can be emitted from the lip opening while suppressing alteration of the sound.

  Furthermore, the dimension of the said clearance gap is 1 mm or more and 10 mm or less at maximum. As a result, it is possible to suppress multiple reflections and resonances of sound waves propagated in the gap, and to reduce peaks (peaks) and dip (valleys) that occur in the frequency response characteristics of sound.

  The dummy head includes a plate in which a through-hole is formed, and the peripheral edge of the plate is fixed to the inner side surface of the casing, so that the space communicates with the outside of the casing through the lip opening. The speaker is divided into a first space that is a portion and a second space that is a remaining portion, and the speaker is inserted into the through hole and fixed to the plate so that the diaphragm is disposed in the first space. The plate may divide the first space into a radiation space formed on the lip opening side of the diaphragm and an excess space formed on the side of the diaphragm.

  According to this structure, it becomes possible to suppress the diffraction of the sound wave to the back side of the speaker by the plate. As a result, the sound wave generated by the speaker can be efficiently emitted to the outside. Furthermore, it is possible to suppress a situation in which the low-frequency reproduction limit frequency decreases due to the sound waves radiated from the back surface of the speaker to the second space in the housing being emitted from the lip opening through the gap.

  The first space is divided into a radiation space formed on the lip opening side with respect to the diaphragm and an excess space formed on the side of the diaphragm. Thereby, the sound wave radiated and reflected from the speaker to the radiation space is guided to the surplus space through the gap, so that the sound wave can be suppressed from being emitted from the lip opening. As a result, it is possible to suppress a situation where the low frequency reproduction limit frequency is lowered.

  The plate may include a sound absorbing material at a portion arranged in the surplus space.

  According to this configuration, by adjusting the amount of the sound absorbing material together with the size of the through hole, the multiple reflection of sound waves in the surplus space is reduced, and the frequency response characteristics of sound waves emitted from the lip opening are adjusted to the optimum ones It becomes possible to do.

  The dummy head may include a diffuser having a curved outer surface in the lip opening.

  According to this configuration, the sound wave passing through the lip opening is diffracted on the outer surface of the diffuser, and is emitted to the outside of the housing while changing its directivity. A sound wave having a low frequency diffracts along the curved surface, and a sound wave having a high frequency tends to diffuse due to interference with the diffuser. Therefore, according to this configuration, the directivity of the sound wave passing through the lip opening can be adjusted by the diffuser, and the frequency response characteristic of the sound wave, particularly the frequency response characteristic in the high sound range can be adjusted.

  The dummy head may include a sound absorbing material in the radiation space.

  According to this configuration, it is possible to reduce multiple reflection and resonance of sound waves in the radiation space. In particular, it is possible to reduce the peak and dip in the middle and high sound range of the frequency response characteristic and to flatten the frequency response characteristic.

  The lip opening may be shielded by a film-like member formed of a sound transmissive material.

  According to this configuration, it is possible to perform blindfolding in the housing while allowing sound waves to be emitted through the lip opening. As the membrane member, a metal fiber plate, a perforated metal plate with a large aperture ratio, a grid-like grille, etc. can be adopted, but the inside of the lip opening is hidden and sound waves are almost completely transmitted over the entire frequency band. Any material can be used as long as it is a permeating material. Since such a film-like member has a slight sound absorption property and an acoustic diffusibility (scattering property) like a diffuser, it can also be used for sound quality adjustment and fine adjustment of frequency response characteristics.

  The dummy head is disposed in a space, has a sound collection port, and includes an ear simulator that detects sound waves taken from the sound collection port, and the case is formed with a passage that communicates the outside of the case with the space, The sound collection port may be disposed so as to take in sound waves emitted from the lip opening to the outside of the housing through the passage.

  According to this configuration, a passage imitating the human external auditory canal is formed in the housing, and sound waves emitted from the mouth of the person by his / her mouth are emitted simultaneously with the sound wave emission by the speaker and the detection by the ear simulator. A dummy head capable of evaluating the influence on hearing can be provided. Such a dummy head can be expected to be applied to various applications such as performance evaluation of mobile phones, development of hearing aids, and auditory research in consideration of the influence of the utterance of the user during a call.

  The dummy head includes a cylindrical member having a bottomed cylindrical shape and a vibration isolating member that attenuates vibration. The cylindrical member is disposed in a space, and the inside of the cylindrical member is a housing through a passage. The ear simulator may be disposed inside the cylindrical member and may be supported by the cylindrical member via a vibration isolating member.

  According to this configuration, since the cylindrical member has a bottomed cylindrical shape, the ear simulator is shielded by the cylindrical member in the space in the housing. For this reason, it is suppressed that the sound wave radiated from the speaker to the space in the housing reaches the ear simulator. As a result, it is possible to configure so that the ear simulator does not detect sound waves reflected in the space in the housing, so-called air propagation sound.

  By the way, a sound wave coming from the outside of the human body and a sound wave (self-speech) emitted from the mouth of a human reach the ear of the person mainly through two kinds of routes. The first path is a path through which sound waves propagate in the air and reach the ear. The sound perceived through the route is referred to as “air conduction sound”. The second path is a path through which sound waves are propagated by solid vibrations such as bone, cartilage, and muscle of the head and reach the ear. The sound perceived through the route is referred to as “bone conduction sound”.

  Returning to the above configuration, the cylindrical member is fixed to the housing, but the ear simulator is supported by the cylindrical member via the vibration isolating member. According to this configuration, even when the vibration of the speaker is propagated to the plate, the casing, and the cylindrical member when the speaker generates a sound wave, the propagation of the vibration to the ear simulator can be suppressed. Become. As a result, it is possible to eliminate the influence of the bone conduction sound and evaluate only the air conduction sound.

  The dummy head may include a fixing member capable of fixing the ear simulator to the cylindrical member and releasing the fixing.

  According to this configuration, the vibration can be solid-propagated from the cylindrical member to the ear simulator by fixing the ear simulator to the cylindrical member using the fixing member. Further, by releasing the fixation of the ear simulator with respect to the cylindrical member, it is possible to suppress the propagation of vibration from the cylindrical member to the ear simulator. That is, according to the above configuration, by appropriately selecting the fixed state of the ear simulator, when detecting the sound wave by the ear simulator, the state reflecting the influence of the bone conduction sound and the state excluding the influence of the bone conduction sound And can be switched.

  Another aspect of the present invention is an earplug attached to a dummy head. The earplug includes a rod-shaped member and a sound insulation member that has elasticity and is connected to the tip of the rod-shaped member. The rod-shaped member has a recess formed on the outer surface thereof. The sound insulation member shields the sound collection port of the ear simulator by inserting the rod-shaped member into the passage.

  According to this configuration, by shielding the sound collection port of the ear simulator with the sound insulation member, it is possible to eliminate the air conduction sound and evaluate only the bone conduction sound. Such a configuration can be effectively used for analysis and development of hearing and hearing aids.

  Further, the rod-shaped member has a recess formed on the outer surface thereof. Therefore, even if a projection imitating a human auricle is formed around the passage of the housing, a gap is formed between the rod-shaped member and the projection by the concave portion to suppress the interference between the two. It becomes possible. As a result, the earplug is inserted into the passage of the housing at an appropriate angle (that is, the angle at which the central axis of the earplug coincides with the central axis of the passage), and the sound collection port of the ear simulator is surely secured by the sound insulation member. It becomes possible to shield.

  The earplug may have a connecting portion that smoothly connects the outer surface of the sound insulating member and the outer surface of the distal end portion of the rod-shaped member in the vicinity of the portion to which the sound insulating member is connected.

  According to this configuration, when the earplug is inserted into the passage of the housing, it is possible to suppress the portion to which the sound insulating member is connected from being caught in the passage.

  ADVANTAGE OF THE INVENTION According to this invention, the dummy head which can emit an audio | voice outside while suppressing a quality change, and the earplug with which it is mounted | worn can be provided.

It is a perspective view which shows the external appearance of the dummy head which concerns on embodiment. It is sectional drawing which shows the II-II cross section of FIG. It is sectional drawing which shows the III-III cross section of FIG. It is a front view of a plate. It is an enlarged view of the lip part vicinity of FIG. It is explanatory drawing explaining the fixed state of an ear simulator. It is an enlarged view of the lip part vicinity of a dummy head. It is a perspective view of the earplug which concerns on embodiment. It is an enlarged view which shows the dummy head equipped with the earplug. It is a graph which shows the frequency response characteristic of the sound wave emitted from the lip opening of the dummy head. It is a graph which shows the frequency response characteristic of the sound wave emitted from the lip opening of the dummy head. It is a graph which shows the frequency response characteristic of the sound wave detected by the ear simulator of the dummy head. It is a graph which shows the frequency response characteristic of the sound wave detected by the ear simulator of the dummy head. It is a graph which shows the frequency response characteristic of the sound wave detected by the ear simulator of the dummy head.

  Hereinafter, embodiments will be described with reference to the accompanying drawings. In order to facilitate the understanding of the description, the same constituent elements in the drawings will be denoted by the same reference numerals as much as possible, and redundant description will be omitted.

  The outline of the dummy head 1 will be described with reference to FIG. FIG. 1 is a perspective view showing the appearance of the dummy head 1. The dummy head 1 includes a housing 2 that has a shape imitating an adult's head. The frame of the housing 2 is formed of a hard resin material, and the surface of the frame is covered with a soft material such as urethane.

  A protrusion simulating a human nose is formed on the front portion of the housing 2. Further, a lip portion 25 imitating the lips is formed below the protrusion. A lip opening 25 a is formed in the lip portion 25. The lip opening 25a penetrates the housing 2 and communicates the outside of the housing 2 with a space 20 inside the housing 2 described later. The vertical dimension of the lip opening 25a is about 20 mm, and the horizontal dimension is about 40 mm.

  The lip opening 25a is shielded by a blindfold cover 26 that is a film-like member formed of a sound-transmitting material. As the blind cover 26, for example, a metal fiber sheet, a metal fiber plate, a fluorine fiber sheet, or the like can be employed. The blind cover 26 has almost 100% sound transmission over a frequency band of 20 Hz to 20 kHz. Moreover, the blindfold cover 26 has a slight sound absorbing property. For this reason, the blindfold cover 26 can be used for adjusting the quality and frequency response characteristics of the sound emitted from the lip opening 25a together with the sound absorbing material 82 described later.

  An ear member 24 simulating a human ear is attached to the side surface of the housing 2. The ear member 24 is attached to both the left and right side surfaces of the housing 2, and FIG. 1 shows the ear member 24 imitating the right ear. The ear member 24 is made of a soft material such as urethane and has a base portion 24a and an auricle portion 24b. The base portion 24a has a rectangular shape in a side view, and the auricle portion 24b protrudes outward from the base portion 24a. The auricle portion 24b functions as a sound collector for sound waves coming from the outside, like a human auricle. A passage 24c simulating the external auditory canal is formed inside the auricle portion 24b. The passage 24c passes through the base 24a.

  Further, a concave portion 23 in which the base portion 24 a of the ear member 24 is mounted is formed on the side surface portion of the housing 2. The base 24a is attached to the recess 23 without a gap. An ear simulator 4 to be described later is disposed inside the recess 23.

  Next, the configuration of the dummy head 1 will be described in detail with reference to FIGS. 2 is a cross-sectional view showing a II-II cross section of FIG. 3 is a cross-sectional view showing a cross section taken along the line III-III in FIG. 2 and 3 schematically show the inside of the housing 2 and only the cross section of the housing 2 is hatched for simplicity. 2 and 3 show the dummy head 1 with the cover 26 shown in FIG. 1 removed. FIG. 4 is a front view of the plate 37. FIG. 5 is an enlarged view of the vicinity of the lip 25 in FIG. FIG. 6 is an explanatory diagram for explaining a fixed state of the ear simulator 4. FIG. 7 is an enlarged view of the vicinity of the lip 25 of the dummy head 1.

  As shown in FIGS. 2 and 3, a space 20 is formed inside the housing 2. A speaker 3, an ear simulator 4, and a cap 5 are arranged in the space 20. A diffuser 7 is disposed inside the lip opening 25a.

  The speaker 3 is a sound source that generates sound waves based on a control signal received from a control device (not shown). The speaker 3 can generate sound waves corresponding to various sounds such as binaurally recorded sound and test sound.

  The speaker 3 has a diaphragm 31 and a function unit 32. The function unit 32 accommodates various elements that function based on control signals, such as coils and magnets. When the functional unit 32 operates based on the control signal, the diaphragm 31 vibrates to generate sound waves. The speaker 3 is fixed with respect to the plate 37.

  The plate 37 shown in FIG. 4 is formed of a thin plate having a thickness of about 0.1 mm to 5 mm. The thickness of the thin plate is about 0.1 mm to 5 mm. The plate 37 has an annular portion 371 and four projecting portions 372. The four protruding portions 372 are formed so as to protrude from the central portion of the annular portion 371 toward one side. The protruding end portions of the four protruding portions 372 are bent so as to face each other, and a through hole 37a is formed between them. An adhesive 37b is attached to the end of each protruding portion 372. Further, glass wool 81 formed of glass fiber is attached to one side surface of the annular portion 371 and around the protruding portion 372. Glass wool 81 functions as a sound absorbing material. The speaker 3 is fixed to the plate 37 by the function portion 32 being inserted through the through hole 37a and adhering to the adhesive 37b.

  As shown in FIGS. 2 and 3, the plate 37 is disposed in a portion of the space 20 of the housing 2 near the lip opening 25 a, and the peripheral edge thereof is fixed to the inner side surface 20 a of the housing 2. . Thus, the space 20 is divided into a first space 21 on the lip opening 25a side and a second space 22 near the center of the space 20. The first space 21 communicates with the outside of the housing 2 through the lip opening 25a. The diaphragm 31 of the speaker 3 is disposed in the first space 21. Between the peripheral edge of the plate 37 and the inner side surface 20a, clay or putty material (not shown) is packed so as to fill the gap.

  Further, by arranging the plate 37 in the space 20 of the housing 2, the first space 21 is divided into a radiation space 21a and a surplus space 21b. The radiation space 21 a is a space formed on the lip opening 25 a side with respect to the diaphragm 31 of the speaker 3. The speaker 3 radiates sound waves to the radiation space 21 a by the vibration of the diaphragm 31. The surplus space 21 b is a space formed on the side of the diaphragm 31 of the speaker 3. The surplus space 21 b is defined by the annular portion 371 of the plate 37, the four projecting portions 372, and the inner side surface 20 a of the housing 2.

  Spacers 84 are arranged in the gaps between the four corners of the periphery of the diaphragm 31 of the speaker 3 and the inner side surface 20a of the housing 2. The spacer 84 is made of a rubber material and has a predetermined elasticity. The dimension L (see FIG. 5) of the gap between the peripheral edge of the diaphragm 31 and the inner side surface 20a of the housing 2 varies depending on the portion because the inner side surface 20a of the housing 2 is a curved surface. It is kept at 1 mm or more and 10 mm or less at the maximum.

  When the plate 37 is fixed to the inner surface 20a of the housing 2, the speaker 3 is arranged so as to cover at least a part of the lip opening 25a from the space 20 side. When the lip opening 25a is viewed from the front, the speaker 3 is arranged so that the center thereof substantially coincides with the center of the lip opening 25a.

  Glass wool 82 is disposed in the radiation space 21a. The glass wool 82 is made of glass fiber, and the thickness thereof is about 1 mm to 5 mm. The glass wool 82 functions as a frequency selective sound transmitting material. Further, glass wool 83a and 83b are arranged in the second space 22. The glass wool 83a and 83b are both made of glass fiber and function as a sound absorbing material.

  The ear simulator 4 is a sound wave detection device having a microphone. For example, a device compliant with IEC60268-7 that is a standard of the International Electrotechnical Commission can be adopted. As shown in FIG. 3, the ear simulator 4 is arranged in a portion corresponding to the inner ear of both ears in the second space 22. The ear simulator 4 includes a main body 41, a sound collection tube 42, and a microphone 43. The main body 41 is made of a metal such as stainless steel, and has a waveguide (not shown) therein. The sound collection cylinder 42 is a cylindrical portion protruding from the main body 41. The sound collection port 42a opened at the tip of the sound collection tube 42 has a conical shape whose diameter gradually decreases toward the inside. The microphone 43 is a known device that converts sound waves into an electrical signal, and for example, an electric condenser microphone can be adopted.

  The cap 5 is an embodiment of a bottomed cylindrical member. As shown in FIG. 3, the cap 5 is formed of a resin material, and includes a cylindrical portion 51 that has a cylindrical shape and a bottom portion 52 that shields one end of the cylindrical portion 51. The cap 5 is disposed in a portion corresponding to the eardrum, middle ear, and inner ear of both ears in the second space 22, and the opening end thereof is fixed to the inner side surface 20 a of the housing 2 without a gap. The tube portion 51 has a communication hole 51a through which the signal line 51b is inserted. In the gap between the communication hole 51a and the signal line 51b, a rubber tube (not shown), a washer, and the like are attached, and the airtightness in the cap 5 is maintained. A plurality of thumbscrews 6 are screwed into the cylindrical portion 51 at different positions in the circumferential direction. The tip of the screwed thumbscrew 6 protrudes into the cap 5. The amount of protrusion of the thumbscrew 6 can be adjusted as appropriate by rotating the thumbscrew 6. A vibration isolating member 53 made of viscoelastic silicon rubber or the like is disposed inside the cap 5.

  The above-described ear simulator 4 is disposed inside the cap 5 and supported by the inner surface of the cap 5 via a vibration isolating member 53. With this arrangement, the ear simulator 4 is isolated from other parts of the second space 22. The ear simulator 4 is disposed such that the sound collection ports 42 a of the sound collection tubes 42 are exposed to the outside on both side surfaces of the housing 2. The microphone 43 transmits an electric signal output from the ear simulator to the outside through a signal line 51 b that is inserted through the communication hole 51 a of the cylindrical portion 51. When the ear member 24 is attached to the recess 23 of the housing 2, the sound collecting cylinder 42 is fitted into the passage 24 c (see FIG. 1) of the ear member 24.

  Further, by adjusting the protrusion amount of the thumbscrew 6 described above, the fixing state of the ear simulator 4 with respect to the cap 5 can be selected as appropriate. Specifically, as shown in FIG. 6 (A), the fixation of the ear simulator 4 to the cap 5 is released by adjusting the thumbscrew 6 so that the tip is separated from the main body 41 of the ear simulator 4. It becomes a state. In this state, even when the housing 2 or the cap 5 vibrates as indicated by the arrow S1, vibration propagation from the cap 5 to the ear simulator 4 (that is, propagation of bone conduction sound which is solid propagation sound) is anti-vibration. It is suppressed by the member 53. That is, the vibration isolating member 53 functions to insulate or attenuate the vibration.

  On the other hand, as shown in FIG. 6B, the ear simulator 4 is fixed to the cap 5 by projecting the thumbscrew 6 so that the tip comes into contact with the main body 41 of the ear simulator 4. . In this state, when the housing 2 or the cap 5 vibrates as indicated by the arrow S <b> 1, the vibration (that is, bone conduction sound) is transmitted to the ear simulator 4 by the thumbscrew 6. That is, the vibration isolating member 53 cannot attenuate the vibration, and the vibration is directly propagated to the ear simulator.

  As shown in FIG. 7, the diffuser 7 is arranged inside the lip opening 25a. The diffuser 7 has a sphere 71 and a rod 72. The spherical body 71 is formed of a hard material such as putty material or caulking material, and has a spherical shape with a diameter of about 3 mm to 10 mm. The rod body 72 is formed of a metal material and has a rod shape. The upper end and the lower end of the rod body 72 are supported by the lip portion 25. Further, the rod 72 supports the sphere 71 so that the sphere 71 is disposed substantially at the center of the lip opening 25 a and the sphere 71 does not protrude from the surface of the housing 2.

  Next, the earplug 100 that is detachably attached to the dummy head 1 will be described with reference to FIGS. FIG. 8 is a perspective view of the earplug 100. FIG. 9 is an enlarged view showing the dummy head 1 to which the earplug 100 is attached. As shown in FIG. 8, the earplug 100 includes a rod-shaped member 110 and a sound insulating member 120.

  The rod-shaped member 110 is formed of a hard material such as wood or resin and has a cylindrical shape. The length of the rod-shaped member 110 is about 10 mm to 50 mm. A recess 111 is formed on a part of the outer surface of the rod-shaped member 110.

  The sound insulation member 120 is formed of an elastic material such as urethane rubber and connected to the tip of the rod-shaped member 110. The thickness of the sound insulation member 120 is about 1 mm to 5 mm. The cross-sectional shape of the sound insulating member 120 is circular, and the diameter thereof is slightly smaller than the inner diameter of the sound collection port 42a of the ear simulator 4.

  The earplug 100 has a connecting portion 130 in the vicinity of the portion to which the sound insulating member 120 is connected. The connecting portion 130 is made of a material whose shape is determined by being cured after molding, such as a putty material or a caulking material. The connecting portion 130 smoothly connects the outer surface of the sound insulating member 120 and the outer surface of the tip portion of the rod-shaped member 110.

  As shown in FIG. 9, the earplug 100 is inserted into the passage 24 c of the ear member 24. The sound insulation member 120 (see FIG. 8) of the inserted earplug 100 shields the sound collection port 42a (see FIG. 6) of the ear simulator 4. At this time, the tragus 24d of the ear member 24 is disposed in the recess 111 of the rod-shaped member 110, whereby interference between the tragus 24d and the rod-shaped member 110 is suppressed. Accordingly, the earplug 100 is inserted into the passage 24c at an appropriate angle (that is, an angle such that the central axis of the earplug 100 coincides with the central axis of the passage 24c), and the sound collection port of the ear simulator 4 by the sound insulating member 120 is inserted. It becomes possible to shield 42a reliably.

  Further, as shown in FIG. 8, since the outer surface of the sound insulating member 120 and the outer surface of the tip of the rod-shaped member 110 are smoothly connected by the connecting portion 130, the earplug 100 is inserted into the passage 24c. At this time, the portion to which the sound insulating member 120 is connected is not caught in the passage 24c.

  As shown in FIG. 3, in addition to the earplug 100, the dummy head 1 can be equipped with a commercially available ear muffler 88 and earplug 89. The ear muffler 88 is attached to both side surfaces of the housing 2 and covers the entire ear member 24. The earplug 89 is inserted into the passage 24c of the ear member 24 and closes the inlet portion of the passage 24c.

<Voice output by dummy head (emission of sound waves)>
The dummy head 1 has a speech function that operates as if a human is speaking by emitting sound waves generated by the speaker 3 from the lip opening 25a to the outside of the housing 2. Thus, the dummy head 1 having a speech function can be expected to be mounted on a robot or the like, and applied to a security (security) related device or system.

  The characteristics of the sound wave emitted by the dummy head 1 according to the embodiment will be described with reference to FIGS. FIG. 10 is a graph showing frequency response characteristics of sound waves emitted from the dummy head according to the comparative example. FIG. 11 is a graph showing the frequency response characteristics of the sound wave emitted from the dummy head and the dummy head 1 according to the comparative example.

  The graphs shown in FIGS. 10 and 11 are based on the results of the utterance test performed on the dummy head according to the comparative example and the dummy head 1 according to the embodiment. In the utterance test, pink noise was applied to the dummy head according to the comparative example and the speaker 3 of the dummy head 1 according to the embodiment, and the sound pressure frequency response characteristics were measured with an external microphone. The external microphone was disposed at a position 20 mm away from the lip opening 25a. The flatter the waveform of the characteristic graph, the more likely it is that the listener perceives it as a natural sound without a sense of incongruity.

  A waveform W1 in FIG. 10 shows the result of the utterance test performed on the dummy head according to the first comparative example. The dummy head is different in configuration from the dummy head 1 according to the embodiment in the following points [a1] to [d1].

[A1] The diffuser 7 is not provided.
[B1] The plate 37 is not provided.
[C1] The dimension L of the gap between the periphery of the diaphragm 31 and the inner surface 20a of the housing 2 is larger than 10 mm.
[D1] The glass wool 82 is not disposed between the lip opening 25a and the diaphragm 31 of the speaker 3.

  In such a dummy head according to the first comparative example, the frequency response characteristic of the sound wave emitted from the lip opening 25a has a steep peak (peak) and dip (valley). As a result, the sound perceived by the listener was greatly distorted.

  A waveform W2 in FIG. 10 shows the result of the utterance test performed on the dummy head according to the second comparative example. The dummy head differs from the dummy head 1 according to the embodiment in the following points [a2] to [d2].

[A2] The diffuser 7 is not provided.
[B2] The plate 37 is not provided.
[C2] Clay was filled between the periphery of the diaphragm 31 and the inner surface 20a of the housing 2 to eliminate the gap.
[D2] The glass wool 82 is not disposed between the lip opening 25a and the diaphragm 31 of the speaker 3.

  In the dummy head according to the second comparative example, the frequency response characteristic of the sound wave emitted from the lip opening 25a generally increases the sound pressure level compared to that of the dummy head according to the first comparative example. The dip became steeper than that of the dummy head according to the first comparative example. As a result, the sound perceived by the listener is much more distorted and far from natural speech. It is considered that this is mainly because the sound wave that could not pass through the lip opening 25 a was reflected by the space 20 inside the housing 2.

  A waveform W3 in FIG. 10 shows the result of the utterance test performed on the dummy head according to the third comparative example. The dummy head differs from the dummy head 1 according to the embodiment in the following points [a3] to [c3]. That is, in the dummy head according to the third comparative example, a gap is formed between the peripheral edge of the diaphragm 31 and the inner surface 20a of the housing 2, and the dimension L of the gap is 1 mm or more and 10 mm or less at the maximum. It is set to be.

[A3] The diffuser 7 is not provided.
[B3] The plate 37 is not provided.
[C3] The glass wool 82 is not arranged between the lip opening 25a and the diaphragm 31 of the speaker 3.

  In such a dummy head according to the third comparative example, the frequency response characteristic of the sound wave emitted from the lip opening 25a is generally flat compared to those of the dummy heads according to the first and second comparative examples. It became. This is because, in the dummy head according to the third comparative example, the sound wave reflected in the radiation space 21a, as shown by the arrow A1 in FIG. It is thought that it was led to the surplus space 21b through the gap between the two. In other words, it is considered that the multiple reflected sound waves are excluded from the radiation space 21a, thereby being prevented from being released to the outside through the lip opening 25a.

  In addition, since the dimension L of the gap between the peripheral edge of the diaphragm 31 and the inner surface 20a of the housing 2 is set to be 1 mm or more and 10 mm or less at the maximum, the multiplexing of the sound waves propagated in the gap is performed. It is thought that the reflection and resonance were suppressed.

  A waveform W4 in FIG. 11 shows the result of the utterance test performed on the dummy head according to the fourth comparative example. The dummy head is different in configuration from the dummy head 1 according to the embodiment in the following points [a4] to [c4]. That is, the dummy head according to the fourth comparative example includes the plate 37 to which the glass wool 81 (see FIG. 4) is not attached.

[A4] The diffuser 7 is not provided.
[B4] The glass wool 82 is not disposed between the lip opening 25a and the diaphragm 31 of the speaker 3.
[C4] Glass wool 81 is not attached to the plate 37.

  In such a dummy head according to the fourth comparative example, the frequency response characteristic of the sound wave emitted from the lip opening 25a is relatively flat as a whole although a plurality of dips appear. The reason for this is considered that the diffraction of the sound wave toward the back side of the speaker 3 is suppressed by the plate 37, and the sound wave generated by the speaker 3 is efficiently emitted from the lip opening 25a.

  A waveform W5 in FIG. 11 shows the result of the utterance test performed on the dummy head according to the fifth comparative example. The dummy head is different in configuration from the dummy head 1 according to the embodiment in the following points [a5] to [c5]. That is, the material of the plate 37 of the dummy head according to the fifth comparative example is different from that of the dummy head plate 37 according to the fourth comparative example.

[A5] The diffuser 7 is not provided.
[B5] Glass wool 82 is not disposed between the lip opening 25a and the diaphragm 31 of the speaker 3.
[C5] Glass wool 81 is not attached to the plate 37.
[D5] The plate 37 is made of aluminum.

  In the dummy head according to the fifth comparative example, the frequency response characteristic of the sound wave emitted from the lip opening 25a is larger than that of the dummy head according to the fifth comparative example. It was.

  A waveform W6 in FIG. 11 shows the result of the utterance test performed on the dummy head 1.

  In the dummy head 1, the frequency response characteristic of the sound wave emitted from the lip opening 25a is flatter. As a result, the sound perceived by the listener is less distorted. This is considered to be because the reflection of sound waves in the first space 21 is suppressed by the glass wool 81 attached to the plate 37, and the frequency response characteristics of the sound waves emitted from the lip opening 25a are adjusted.

  The sound wave passing through the lip opening 25a is diffracted on the outer surface of the sphere 71 of the diffuser 7 and emitted to the outside of the housing 2 while changing its directivity. A sound wave having a low frequency is diffracted along the curved surface, and a sound wave having a high frequency tends to diffuse due to interference with the sphere 71. Therefore, the directivity of the sound wave passing through the lip opening 25a is adjusted by the sphere 71, and the frequency response characteristic of the sound wave is adjusted, and the frequency response characteristic of the sound wave emitted from the lip opening 25a becomes flat. It is thought to be a factor.

  In the dummy head 1, glass wool 82 as a sound absorbing material is disposed between the lip opening 25 a and the diaphragm 31 of the speaker 3. With this configuration, multiple reflection of sound waves and resonance between the portion of the inner surface 20a of the housing 2 around the lip opening 25a and the diaphragm 31 are reduced, and selective transmission according to the frequency band is effective. It is considered that the frequency response characteristic of the sound wave emitted from the lip opening 25a is flat.

<Voice production and listening with dummy head (emission and reception of sound waves)>
The dummy head 1 also has a listening function for receiving sound waves by the ear simulator 4 in addition to the above-mentioned utterance function. In this way, the dummy head 1 capable of performing voice and listening at the same time is a performance evaluation of a mobile phone considering the influence of the voice during the user's call, development of a hearing aid, research area on hearing and self-speech, etc. Application to various purposes can be expected.

  With reference to FIG. 12 and FIG. 13, the characteristics of sound waves received by the dummy head 1 and received and detected by its own ear simulator (that is, characteristics of listening to self-speech) will be described. In addition, the effect of the earplug 100 will also be described. FIGS. 12 and 13 are graphs showing the frequency response characteristics of sound waves detected by the ear simulator 4 of the same dummy head 1 when pink noise is applied from the speaker 3 of the dummy head 1.

  The graphs shown in FIGS. 12 and 13 are based on the results of a self-speech listening test performed on the dummy head 1. In the self-speech listening test, pink noise was generated by the speaker 3 of the dummy head 1 and sound waves were detected by the ear simulator 4.

  The characteristics shown by the bar B1 in FIGS. 12 and 13 correspond to the background noise of the measurement system including the self noise of the microphone 43 of the ear simulator 4. That is, the microphone 43 cannot detect a sound wave having a sound pressure level smaller than that of the bar B1.

  FIG. 12 shows the result of the self-speech listening test in a state where the fixation of the ear simulator 4 by the thumbscrew 6 is released as shown in FIG. In this state, the vibration is attenuated by the vibration isolating member 53, so that the propagation of vibration from the cap 5 to the ear simulator 4 is suppressed. That is, the sound wave propagating through the housing 2 is blocked, and only the sound wave propagating through the air as indicated by the arrow A2 is detected by the ear simulator 4. As a result, it is possible to eliminate the influence of the bone conduction sound and evaluate only the air conduction sound.

  A waveform W7 in FIG. 12 shows the result of a self-speech listening test performed on the dummy head 1 in a state where the ear member 24 is not attached. A waveform W8 shows the result of a self-speech listening test performed on the dummy head 1 with the ear member 24 attached. It can be seen that the characteristics of the sound wave detected by the ear simulator 4 has changed due to the wearing of the ear member 24.

  A waveform W9 in FIG. 12 shows a result of a self-speech listening test performed on the dummy head 1 in a state where the ear member 24 is covered with the ear muffler 88. A waveform W10 indicates the result of a self-speech listening test performed on the dummy head 1 in a state where the passage 24c of the ear member 24 is blocked by a commercially available earplug 89. In either case, a decrease in sound pressure level was observed in the high frequency region, but the result showed that the sound pressure level hardly changed or rather increased in the low frequency region. This is an interesting result corresponding to the sound quality of self-speech when a finger is put in the ear hole, and suggests that attention should be paid to speech with earplugs attached.

  The waveform W11 in FIG. 13 shows the dummy head 1 in a state where the ear simulator 4 is fixed by the thumbscrew 6 (see FIG. 6B) and the passage 24c of the ear member 24 is blocked by a commercially available earplug 89. Shows the results of a self-speech listening test conducted for. The waveform W12 is the self-speech listening performed on the dummy head 1 with the earplug 100 inserted into the passage 24c of the ear member 24 while the ear simulator 4 is fixed (FIG. 6A). The test results are shown. That is, the result shows a response in a state where both the air conduction sound and the bone conduction sound are blocked with respect to the self-utterance.

  The waveform W11 has an increase in sound pressure level of about 20 dB compared to the waveform W12. In the waveform W11, the ear simulator 4 is fixed by the thumbscrew 6 so that the vibration isolating member 53 cannot attenuate the vibration, and the solid propagation sound (that is, bone conduction sound) propagating through the housing 2 is unpleasant. This is considered to be a result detected by the simulator 4. That is, it is considered that the ear simulator 4 detected only the sound wave corresponding to the bone conduction sound in the real head.

<Listening to external sound with a dummy head (acoustic wave reception)>
The dummy head 1 can also enable only the listening function and listen to only the external sound. For example, binaural recording or recording of a head-related transfer function (HRTF) can be performed by detecting a sound wave reaching from the outside by the ear simulator 4.

  With reference to FIG. 14, the characteristics of the sound wave radiated from the external sound source and detected by the dummy head 1 will be described. FIG. 14 is a graph showing frequency response characteristics of sound waves detected by the ear simulator 4.

  The graph shown in FIG. 14 is based on the result of a listening test performed on the dummy head 1. In the listening test, pink noise was applied to the speaker disposed at a position approximately 1000 mm ahead of the dummy head 1, and sound waves were detected by the ear simulator 4 to measure the sound pressure response. At this time, as shown in FIG. 6A, the fixation of the ear simulator 4 by the thumbscrew 6 is released.

  The characteristic indicated by the bar B2 corresponds to the background noise of the measurement system including the self noise of the microphone 43 of the ear simulator 4. That is, the microphone 43 cannot detect a sound wave having a sound pressure level smaller than that of the bar B2.

  A waveform W13 indicates the result of a listening test performed on the dummy head 1 in a state where the ear member 24 is not attached. A waveform W14 shows the result of a listening test performed on the dummy head 1 with the ear member 24 attached. It can be seen that the characteristics of the sound wave detected by the ear simulator 4 has changed due to the wearing of the ear member 24.

  A waveform W15 indicates the result of a listening test performed on the dummy head 1 in a state where the ear member 24 is covered with the ear muffler 88. A waveform W16 shows the result of a listening test performed on the dummy head 1 in a state where the passage 24c of the ear member 24 is blocked with clay. In either case, a decrease in sound pressure level was observed in the high frequency region, but the result showed that the sound pressure level hardly changed in the low frequency region.

  A waveform W17 shows the result of a listening test performed on the dummy head 1 in a state where the earplug 100 is inserted into the passage 24c of the ear member 24. It can be seen that the sound collection opening 42a of the ear simulator 4 is effectively shielded by the sound insulation member 120 of the earplug 100, and the sound pressure level is reduced to the same level as the bar B2 corresponding to the background noise.

  The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. In other words, those specific examples that have been appropriately modified by those skilled in the art are also included in the scope of the present invention as long as they have the characteristics of the present invention. Each element included in each of the specific examples described above and their arrangement, material, condition, shape, size, and the like are not limited to those illustrated, and can be changed as appropriate.

  For example, a passage corresponding to a human nostril may be formed in the nose of the dummy head 1. By connecting the inside and outside of the housing 2 through the passage, the sound quality adjustment range can be expanded, and the effective opening area can be increased to improve the sound quality and radiation efficiency.

1: Dummy head 2: Housing 3: Speaker 4: Ear simulator 5: Cap (tubular member)
6: Thumbscrew (fixing member)
7: Diffuser 20: Space 21: First space 22: Second space 24c: Passage 25a: Lip opening 31: Diaphragm 37: Plate 37a: Through hole 42a: Sound collection port 51: Tube portion 53: Anti-vibration member 81: Glass wool (sound absorbing material)
82: Glass wool (sound absorbing material)
100: Earplug 110 Bar-shaped member 111: Recess 120: Sound insulation member 130: Connection part

Claims (11)

A dummy head that emits sound to the outside,
A housing in which a space is formed;
A speaker disposed in the space and generating a sound wave by vibrating the diaphragm,
The casing is formed with a lip opening that allows communication between the outside of the casing and the space.
The speaker is disposed so as to cover at least a part of the lip opening from the space side and to form a gap between a peripheral portion of the speaker and an inner side surface of the housing.
The dummy head has a maximum dimension of 1 mm or more and 10 mm or less. Comprising a plate with through-holes formed;
The plate has a peripheral portion fixed to the inner side surface of the housing, whereby the space communicates with the outside of the housing through the lip opening, and a remaining portion. And the second space,
The speaker is inserted into the through hole and fixed to the plate so that the diaphragm is disposed in the first space.
The said plate divides said 1st space into the radiation space formed in the said lip opening side rather than the said diaphragm, and the surplus space formed in the side of the said diaphragm. Dummy head.   The dummy head according to claim 2, wherein the plate includes a sound absorbing material at a portion disposed in the surplus space.   The dummy head according to any one of claims 1 to 3, further comprising a diffuser having an outer surface formed by a curved surface in the lip opening.   The dummy head according to claim 1, further comprising a sound absorbing material in the radiation space.   The dummy head according to any one of claims 1 to 5, wherein the lip opening is shielded by a film-like member made of a sound-transmitting material. An ear simulator disposed in the space, having a sound collection port, for detecting a sound wave taken from the sound collection port;
The casing is formed with a passage that communicates the outside of the casing with the space.
The dummy head according to any one of claims 1 to 6, wherein the sound collection port is disposed so as to take in a sound wave emitted from the lip opening to the outside of the casing through the passage. . A tubular member having a bottomed tubular shape;
An anti-vibration member that attenuates vibration,
The cylindrical member is disposed in the space, and is fixed to the casing so that the inside of the cylindrical member communicates with the outside of the casing through the passage.
The dummy head according to claim 7, wherein the ear simulator is disposed inside the cylindrical member and supported by the cylindrical member via the vibration isolation member.   The dummy head according to claim 8, further comprising a fixing member capable of fixing the ear simulator to the cylindrical member and releasing the fixing. An earplug attached to the dummy head according to any one of claims 7 to 9,
A rod-shaped member;
A sound insulation member having elasticity and connected to the tip of the rod-shaped member,
The rod-shaped member has a recess formed on the outer surface thereof,
The sound insulation member is an earplug that shields the sound collection port of the ear simulator by inserting the rod-shaped member into the passage.   The earplug according to claim 10, further comprising a connecting portion that smoothly connects the outer surface of the sound insulating member and the outer surface of the tip of the rod-shaped member in the vicinity of a portion to which the sound insulating member is connected. .