JP6667464B2 - Dummy head - Google Patents

Description

  The present invention relates to a dummy head for detecting sound and earplugs.

  The human ear perceives sound by receiving sound waves that are diffracted and reflected intricately at the pinna and the like. If a sound wave affected by such an auricle or the like is received by a microphone, recorded as it is, and reproduced, the listener can perceive a sound with a more three-dimensional effect. That is, the listener can be made to feel that he or she is listening to a sound close to the original sound.

  Recording / reproduction that reflects the influence of the pinna or the like is referred to as binaural recording / reproduction, and is performed using, for example, a dummy head described in Patent Document 1. The dummy head has a housing imitating a human head, and a protrusion imitating an auricle and a passage imitating an external auditory canal are formed in the housing. Further, an ear simulator having a microphone is arranged in a portion corresponding to the inner ear of a human.

  Such a dummy head receives a sound wave diffracted / reflected by a housing or a projection and passed through the passage by an ear simulator, thereby obtaining a head similar to an actual human head (hereinafter also referred to as “real head”). It can measure the head-related transfer function (HRTF). Binaural recording is enabled by convolving the head-related transfer function or a head-related impulse response (HRIR) obtained by performing an inverse Fourier transform on the head-related transfer function with a signal.

JP-A-5-153687

  A sound wave arriving from the outside of the human body and a sound wave emitted from a human mouth (self-speech) reach their own ear mainly through two types of paths. The first path is a path in which the sound wave propagates in the air and reaches the ear. The voice perceived via the path is referred to as “air conduction sound”. The second route is a route in which sound waves are propagated by solid vibrations such as bones, cartilage, and muscles of the head and reach the ears. The voice perceived via the path is called “bone conduction sound”.

  Also in the dummy head, it is preferable that the air conduction sound can be detected separately from the bone conduction sound. Such a dummy head can be expected to be applied to various uses such as recording that requires high quality such as high-resolution recording, development of hearing aids, and research on hearing.

  However, the ear simulator needs to be fixed to the housing at a portion corresponding to the inner ear of a human. For this reason, there has been a problem that sound waves that propagate through the solid due to the vibration of the housing reach the ear simulator, and a sound corresponding to the bone conduction sound is detected by the ear simulator.

  The present invention has been made in view of such a problem, and it is an object of the present invention to provide a dummy head capable of detecting air conduction sound separately from bone conduction sound and an earplug attached to the dummy head. Aim.

  One embodiment of the present invention for solving the above-described problem is a dummy head for detecting sound, which includes a housing having a space formed therein, a sound collection port provided in the space, and a sound collection port. An ear simulator for detecting sound waves taken in from the mouth and a vibration isolating member for attenuating vibration are provided. The housing is provided with a passage for communicating the outside of the housing with the space. The sound collecting port of the ear simulator is arranged so as to take in a sound wave arriving from the outside of the housing via a passage. The ear simulator is fixed to the housing via an anti-vibration member.

  According to this configuration, even when the housing vibrates and a sound wave propagates, the propagation of the vibration to the ear simulator can be suppressed by the vibration isolating member. As a result, it is possible to eliminate the influence of bone conduction sounds and to evaluate only air conduction sounds.

  The dummy head is disposed in a space, has a bottomed cylindrical shape, and includes a cylindrical member fixed to the housing so that the inside communicates with the outside of the housing via a passage. It may be arranged inside the tubular member and supported by the tubular member via a vibration isolating member.

  According to this configuration, since the tubular member has a bottomed tubular shape, the ear simulator is shielded by the tubular member in the space inside the housing. For this reason, it is possible to suppress the sound waves (that is, air conduction sounds, so-called air propagation sounds) radiated into the space inside the housing due to the vibration of the housing from reaching the ear simulator. As a result, the detection of the sound wave by the ear simulator can be suppressed.

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

  According to this configuration, by fixing the ear simulator to the cylindrical member using the fixing member, the vibration isolating function of the vibration isolating member can be eliminated, and vibration can be propagated from the cylindrical member to the ear simulator. . Further, by releasing the fixation of the ear simulator to the tubular member, propagation of vibration (that is, bone conduction sound, so-called solid propagation sound) from the tubular member to the ear simulator can be suppressed. In other words, according to the above configuration, by appropriately selecting the fixed state of the ear simulator, when the sound wave is detected by the ear simulator, a state in which the influence of the bone conduction sound is reflected and a state in which the influence of the bone conduction sound is excluded. And can be switched.

  The dummy head is provided in a space, and includes a speaker that generates a sound wave by vibrating a diaphragm.The housing has a lip opening that allows communication between the outside of the housing and the space, and the speaker is arranged from the space side. It may be arranged so as to cover at least a part of the lip opening.

  According to this configuration, it is possible to provide a dummy head capable of evaluating the effect of a human voice emitted from his / her own mouth on hearing by simultaneously emitting a sound wave from a speaker and detecting the sound wave by an ear simulator. Can be. Such a dummy head can be expected to be applied to various uses such as performance evaluation of a mobile phone in consideration of the influence of utterance during a user's call, development of a hearing aid, and research on hearing.

  The dummy head includes a plate having a through-hole formed therein, and the plate has a peripheral portion fixed to an inner surface of the housing, thereby communicating the space with the outside of the housing via the lip opening. The speaker is divided into a first space that is a part and a second space that is a remaining part, and the speaker is inserted into the through hole and fixed to the plate so that the diaphragm is arranged in the first space. The tubular member and the ear simulator may be arranged in the second space.

  According to this configuration, it is possible to suppress the diffraction of the sound wave to the back side of the speaker by the plate. As a result, sound waves radiated from the speaker to the space inside the housing can be suppressed from reaching the ear simulator via the space. As a result, the detection of the sound wave by the ear simulator can be suppressed.

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

  According to this configuration, sound waves emitted from the rear surface of the speaker to the second space in the housing and reflected by the second space can be absorbed by the sound absorbing material. As a result, the detection of the sound wave by the ear simulator can be suppressed.

  Another embodiment of the present invention is an earplug mounted on a dummy head. The earplug includes a rod-shaped member and a sound insulating member having elasticity and connected to a distal end of the rod-shaped member. The rod-shaped member has a concave portion formed on an outer surface thereof. The sound insulating member shields the sound collecting port of the ear simulator by inserting the rod-shaped member into the passage.

  According to this configuration, the sound collecting member of the ear simulator is shielded by the sound insulating member, so that air conduction sound can be excluded and only bone conduction sound can be evaluated. That is, with this configuration, it is possible to switch between a state in which the influence of the air conduction sound is reflected and a state in which the influence of the air conduction sound is eliminated when detecting the sound wave by the ear simulator. Such a configuration can be effectively used for the analysis and development of hearing and hearing aids.

  Further, the rod-shaped member has a concave portion formed on an outer surface thereof. Therefore, even when a protrusion imitating a human pinna is formed around the passage of the housing, a gap is formed between the rod-shaped member and the protrusion by the concave portion to suppress 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, an angle at which the center axis of the earplug coincides with the center axis of the passage), and the sound collection member of the ear simulator is securely inserted by the sound insulating member. It becomes possible to shield.

  The earplug may have a connecting portion near the portion to which the sound insulating member is connected, for smoothly connecting the outer surface of the sound insulating member and the outer surface of the distal end portion of the rod-shaped member.

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

  According to the present invention, it is possible to provide a dummy head capable of detecting air-conducted sound separately from bone-conducted sound, and an earplug attached to the dummy head.

FIG. 2 is a perspective view illustrating an appearance of a dummy head according to the embodiment. It is sectional drawing which shows the II-II cross section of FIG. FIG. 3 is a sectional view showing a section taken along line III-III of FIG. 2. It is a front view of a plate. FIG. 3 is an enlarged view of the vicinity of a lip in FIG. 2. FIG. 4 is an explanatory diagram illustrating a fixed state of the ear simulator. It is an enlarged view near the lip part of a dummy head. It is a perspective view of an earplug concerning an embodiment. FIG. 3 is an enlarged view showing a dummy head to which earplugs are attached. 6 is a graph showing a frequency response characteristic of a sound wave emitted from a lip opening of a dummy head. 6 is a graph showing a frequency response characteristic of a sound wave emitted from a lip opening of a dummy head. 5 is a graph illustrating frequency response characteristics of a sound wave detected by an ear simulator of a dummy head. 5 is a graph illustrating frequency response characteristics of a sound wave detected by an ear simulator of a dummy head. 5 is a graph illustrating frequency response characteristics of a sound wave detected by an ear simulator of a dummy head.

  Hereinafter, embodiments will be described with reference to the accompanying drawings. To facilitate understanding of the description, the same components are denoted by the same reference numerals as much as possible in each drawing, 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 having a shape imitating an adult's head. The skeleton of the housing 2 is formed of a hard resin material, and the surface of the skeleton is covered with a soft material such as urethane.

  On the front part of the housing 2, a projection imitating a human nose is formed. A lip portion 25 imitating a lip is formed below the projection. The lip portion 25 has a lip opening 25a. 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 blind cover 26, which 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 used. The blind cover 26 has almost 100% sound transmission over a frequency band of 20 Hz to 20 kHz. The blind cover 26 also has a slight sound absorbing property. For this reason, the blind cover 26 can be used together with the sound absorbing material 82 described later to adjust the quality and frequency response characteristics of the sound emitted from the lip opening 25a.

  An ear member 24 imitating a human ear is attached to a side surface of the housing 2. The ear members 24 are attached to the left and right side surfaces of the housing 2, and FIG. 1 shows the ear members 24 imitating the right ear. The ear member 24 is formed of a soft material such as urethane, and has a base 24a and an auricle 24b. The base 24a has a rectangular shape in a side view, and the auricle 24b projects outward from the base 24a. The pinna part 24b functions as a sound collector for sound waves arriving from the outside, similarly to the human pinna. Inside the auricle part 24b, a passage 24c imitating the external auditory canal is formed. The passage 24c passes through the base 24a.

  In addition, a concave portion 23 in which the base 24a of the ear member 24 is mounted is formed on a side surface of the housing 2. The base 24a is mounted in the recess 23 without any gap. An ear simulator 4 described later is arranged inside the concave portion 23.

  Next, the configuration of the dummy head 1 will be described in detail with reference to FIGS. FIG. 2 is a sectional view showing a II-II section of FIG. FIG. 3 is a sectional view showing a section taken along line III-III of FIG. 2 and 3, the inside of the housing 2 is schematically shown, and only the cross section of the housing 2 is hatched for simplicity. FIGS. 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 illustrating a fixed state of the ear simulator 4. FIG. 7 is an enlarged view near the lips 25 of the dummy head 1.

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

  The speaker 3 is a sound source that generates a sound wave 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 a binaurally recorded sound and a test sound.

  The speaker 3 has a diaphragm 31 and a functional unit 32. Various elements that function based on control signals, such as coils and magnets, are housed in the functional unit 32. When the functional unit 32 operates based on the control signal, the diaphragm 31 vibrates to generate a sound wave. The speaker 3 is fixed 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 protrusions 372 are formed so as to protrude from the center of the annular portion 371 toward one side. The ends of the four protruding projections 372 are bent so as to face each other, and a through hole 37a is formed therebetween. An adhesive 37b is attached to an end of each protruding portion 372. Further, glass wool 81 formed of glass fiber is adhered on one side surface of the annular portion 371 and around the protruding portion 372. The glass wool 81 functions as a sound absorbing material. The speaker 3 is fixed to the plate 37 by inserting the functional part 32 into the through hole 37a and adhering to the adhesive 37b.

  As shown in FIGS. 2 and 3, the plate 37 is arranged at a position near the lip opening 25 a in the space 20 of the housing 2, and its peripheral edge is fixed to the inner side surface 20 a of the housing 2. . Thereby, the space 20 is divided into a first space 21 on the side of the lip opening 25a and a second space 22 near the center of the space 20. The first space 21 communicates with the outside of the housing 2 via the lip opening 25a. The diaphragm 31 of the speaker 3 is disposed in the first space 21. Clay or putty (not shown) is filled between the peripheral portion of the plate 37 and the inner surface 20a so as to fill the gap.

  Further, by disposing 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 21a is a space formed closer to the lip opening 25a than the diaphragm 31 of the speaker 3. The speaker 3 emits a sound wave to the radiation space 21a by the vibration of the diaphragm 31. The surplus space 21b is a space formed on the side of the diaphragm 31 of the speaker 3. The surplus space 21b is defined by the annular portion 371 of the plate 37, the four projecting portions 372, and the inner surface 20a of the housing 2.

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

  When the plate 37 is fixed to the inner side 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 directly, the speaker 3 is arranged such that the center thereof substantially coincides with the center of the lip opening 25a.

  Glass wool 82 is arranged in the radiation space 21a. The glass wool 82 is formed of glass fiber and has a thickness of about 1 mm to 5 mm. The glass wool 82 functions as a frequency-selective sound transmitting material. Further, glass wools 83a and 83b are arranged in the second space 22. Each of the glass wools 83a and 83b is formed of glass fiber and functions as a sound absorbing material.

  The ear simulator 4 is a sound wave detection device having a microphone, and for example, a device based on IEC60268-7 which is a standard of the International Electrotechnical Commission can be adopted. As shown in FIG. 3, the ear simulator 4 is disposed in the second space 22 at a position corresponding to the inner ear of both ears. The ear simulator 4 has a main body 41, a sound collecting cylinder 42, and a microphone 43. The main body 41 is formed of a metal such as stainless steel, and has a waveguide (not shown) therein. The sound collecting cylinder 42 is a cylindrical part protruding from the main body 41. The sound collecting port 42a formed at the tip of the sound collecting cylinder 42 has a conical shape whose diameter gradually decreases toward the inside. The microphone 43 is a known device that converts a sound wave into an electric signal, and may employ, for example, an electric condenser microphone.

  The cap 5 is an embodiment of a bottomed tubular member. The cap 5 is formed of a resin material, and has a cylindrical portion 51 having a cylindrical shape and a bottom portion 52 that shields one end of the cylindrical portion 51, as shown in FIG. The cap 5 is disposed at a position corresponding to the eardrum, the middle ear, and the inner ear of both ears in the second space 22, and the open end thereof is fixed to the inner surface 20 a of the housing 2 without any gap. A communication hole 51a through which the signal line 51b is inserted is formed in the cylindrical portion 51. A rubber tube (not shown), a washer, or the like is attached to a gap between the communication hole 51a and the signal line 51b, and the airtightness in the cap 5 is maintained. A plurality of thumb screws 6 are screwed into the cylindrical portion 51 at positions different from each other in the circumferential direction. The tip of the threaded thumb screw 6 projects into the cap 5. The protrusion amount of the thumb screw 6 can be appropriately adjusted by rotating the thumb screw 6. Inside the cap 5, a vibration isolating member 53 made of viscoelastic silicon rubber or the like is arranged.

  The above-described ear simulator 4 is disposed inside the cap 5 and is supported by the inner side surface of the cap 5 via a vibration isolating member 53. With this arrangement, the ear simulator 4 is isolated from other portions of the second space 22. The ear simulator 4 is arranged such that the sound collecting port 42 a of the sound collecting cylinder 42 is 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 51b inserted through the communication hole 51a of the cylindrical portion 51. When the ear member 24 is attached to the concave portion 23 of the housing 2, the sound collection tube 42 fits into the passage 24 c of the ear member 24 (see FIG. 1).

  Further, by adjusting the amount of protrusion of the thumb screw 6 described above, the fixing state of the ear simulator 4 to the cap 5 can be appropriately selected. Specifically, as shown in FIG. 6A, the fixing of the ear simulator 4 to the cap 5 is released by adjusting the thumb screw 6 so that the tip is separated from the main body 41 of the ear simulator 4. State. In this state, even if the housing 2 or the cap 5 vibrates as shown by the arrow S1, the propagation of the vibration from the cap 5 to the ear simulator 4 (that is, the propagation of the bone conduction sound that is the solid-borne 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 protruding the thumb screw 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 and the cap 5 vibrate as indicated by the arrow S1, the vibration (ie, bone conduction sound) is transmitted to the ear simulator 4 by the thumb screw 6. That is, the vibration isolator 53 cannot attenuate the vibration, and the vibration propagates to the ear simulator as it is.

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

  Next, the earplug 100 detachably attached to the dummy head 1 will be described with reference to FIGS. 8 and 9. 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 has a rod-shaped member 110 and a sound insulation member 120.

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

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

  The earplug 100 has a connecting portion 130 near the portion where the sound insulating member 120 is connected. The connecting part 130 is formed of a material such as a putty material or a caulking material, which hardens after molding and has a determined shape. The connecting portion 130 smoothly connects the outer surface of the sound insulating member 120 and the outer surface of the distal end portion of the rod-shaped member 110.

  As shown in FIG. 9, the earplug 100 is inserted into the passage 24c 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, since the tragus 24d of the ear member 24 is disposed in the concave portion 111 of the rod-shaped member 110, interference between the tragus 24d and the rod-shaped member 110 is suppressed. As a result, 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 insulating member 120 causes the sound collecting port of the ear simulator 4 to be inserted. 42a can be reliably shielded.

  Also, as shown in FIG. 8, since the outer surface of the sound insulating member 120 and the outer surface of the distal end 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 does not get caught in the passage 24c.

  As shown in FIG. 3, besides the earplug 100, a commercially available ear muffler 88 and earplug 89 can be attached to the dummy head 1. The ear mufflers 88 are mounted on both side surfaces of the housing 2 and cover the entire ear member 24. The earplug 89 is inserted into the passage 24c of the ear member 24, and closes the entrance of the passage 24c.

<Speech by dummy head (emission of sound wave)>
The dummy head 1 has an utterance function of operating as if a human is uttering by emitting a sound wave generated by the speaker 3 to the outside of the housing 2 from the lip opening 25a. The dummy head 1 having the vocalization function as described above can be expected to be mounted on a robot or the like, and applied to security (security) related devices and systems.

  The characteristics of the sound waves emitted by the dummy head 1 according to the embodiment will be described with reference to FIGS. FIG. 10 is a graph illustrating frequency response characteristics of sound waves emitted from the dummy head according to the comparative example. FIG. 11 is a graph illustrating 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 a voice 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 using an external microphone. The external microphone was arranged at a position 20 mm forward from the lip opening 25a. As the waveform of the characteristic graph becomes flatter, the listener tends to perceive the natural sound as a natural sound without any discomfort.

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

[A1] Diffuser 7 is not provided.
[B1] No plate 37 is provided.
[C1] The dimension L of the gap between the peripheral edge of the diaphragm 31 and the inner side 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 the dummy head according to the first comparative example, the frequency response characteristic of the sound wave emitted from the lip opening 25a has a sharp peak (peak) or dip (valley). As a result, the voice perceived by the listener was greatly distorted.

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

[A2] Diffuser 7 is not provided.
[B2] No plate 37 is provided.
[C2] Clay was filled between the peripheral edge 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 sound pressure level of the sound wave emitted from the lip opening 25a was generally higher than that of the dummy head according to the first comparative example. The dip was steeper than that of the dummy head according to the first comparative example. As a result, the sound perceived by the listener became much more distorted and far from natural utterance. This is considered to be mainly because sound waves that could not pass through the lip opening 25a were 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 configuration of the dummy head differs from that of 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 side 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] Diffuser 7 is not provided.
[B3] No plate 37 is provided.
[C3] 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 third comparative example, the frequency response characteristic of the sound wave emitted from the lip opening 25a is generally flatter than that of the dummy head 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 is transmitted to the peripheral edge of the diaphragm 31 and the inner surface 20a of the housing 2 as indicated by an arrow A1 in FIG. Is led to the surplus space 21b via the gap between the two. In other words, it is considered that, by excluding the multiply-reflected sound waves from the radiation space 21a, emission of the sound waves to the outside through the lip opening 25a is suppressed.

  In addition, since the dimension L of the gap between the peripheral edge of the diaphragm 31 and the inner side surface 20a of the housing 2 is set to be 1 mm or more and 10 mm or less at the maximum, multiplexing of sound waves propagated to the gap is achieved. It is also considered 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 configuration of the dummy head differs from that of 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] No diffuser 7 is provided.
[B4] The glass wool 82 is not disposed between the lip opening 25a and the diaphragm 31 of the speaker 3.
[C4] The glass wool 81 is not attached to the plate 37.

  In the dummy head according to the fourth comparative example, the frequency response characteristic of the sound wave emitted from the lip opening 25a was relatively flat as a whole, although a plurality of dips appeared. It is considered that the reason is that the diffraction of the sound wave to 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 configuration of the dummy head differs from that of 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 plate 37 of the dummy head according to the fourth comparative example.

[A5] No diffuser 7 is provided.
[B5] The glass wool 82 is not disposed between the lip opening 25a and the diaphragm 31 of the speaker 3.
[C5] The glass wool 81 is not attached to the plate 37.
[D5] The plate 37 is formed of aluminum.

  In the dummy head according to the fifth comparative example, the result is obtained that 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. Was done.

  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 characteristics of the sound wave emitted from the lip opening 25a became flatter. As a result, the voice perceived by the listener has less distortion. It is considered that the reason is that the reflection of the sound wave in the first space 21 was suppressed by the glass wool 81 adhered to the plate 37, and the frequency response characteristic of the sound wave emitted from the lip opening 25a was 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. Low-frequency sound waves tend to diffract along a curved surface, and high-frequency sound waves tend 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 considered a factor.

  Further, 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 and resonance of sound waves between the portion around the lip opening 25a on the inner side surface 20a of the housing 2 and the diaphragm 31 are reduced, and selective transmission according to the frequency band is effective. It is also considered that the frequency response characteristics of the sound waves emitted from the lip opening 25a become flat.

<Speech and listening by the dummy head (emission and reception of sound waves)>
The dummy head 1 has a listening function of receiving a sound wave by the ear simulator 4 in addition to the above-described utterance function. As described above, the dummy head 1 capable of simultaneously performing utterance and listening can be used for a mobile phone performance evaluation in consideration of the effect of utterance when a user talks, development of a hearing aid, a research area related to hearing and self-utterance, and the like. It can be expected to be applied to various uses.

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

  The graphs shown in FIG. 12 and FIG. 13 are based on the results of a self-utterance 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 indicated 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-utterance listening test in a state where the fixing of the ear simulator 4 by the thumb screw 6 is released as shown in FIG. In this state, since the vibration is attenuated by the vibration isolating member 53, the propagation of the vibration from the cap 5 to the ear simulator 4 is suppressed. That is, the sound wave propagating in the housing 2 is cut off, and only the sound wave propagating in 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 a result of a self-utterance listening test performed on the dummy head 1 without the ear member 24 attached. A waveform W8 indicates the result of a self-utterance 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 have changed due to the mounting of the ear member 24.

  A waveform W9 in FIG. 12 shows a result of a self-utterance listening test performed on the dummy head 1 in a state where the ear member 24 is covered with the ear muffler 88. The waveform W10 shows 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 closed by the commercially available earplug 89. In each case, a decrease in the sound pressure level was observed in the high frequency region, but the sound pressure level hardly changed or increased in the low frequency region. This is an interesting result corresponding to the sound quality of self-utterance when a finger is inserted into the ear canal, and suggests that attention must 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 thumb screw 6 (see FIG. 6B) and the passage 24c of the ear member 24 is closed by a commercially available earplug 89. 9 shows the results of a self-utterance listening test performed on the test. In addition, the waveform W12 indicates that the ear simulator 4 is released from the fixed state (FIG. 6A), and that the self-speech listening / listening performed on the dummy head 1 in a state where the earplug 100 is inserted into the passage 24c of the ear member 24. The results of the test are shown. That is, the result indicates a response in a state in which both the air-conducted sound and the bone-conducted sound are blocked to the self-utterance.

  In the waveform W11, an increase in the sound pressure level by about 20 dB compared to the waveform W12 is recognized. This is because in the waveform W11, the ear simulator 4 is fixed by the thumb screw 6, the vibration isolator 53 cannot attenuate the vibration, and the solid-borne sound (that is, the bone conduction sound) propagating through the housing 2 is generated. This is considered to be the result detected by the simulator 4. That is, it is considered that the ear simulator 4 detects only the sound wave corresponding to the bone conduction sound in the real head.

<Receiving external sound with a dummy head (receiving sound waves)>
The dummy head 1 enables only the listening function, and can receive only the external sound. By detecting sound waves arriving from the outside by the ear simulator 4, for example, binaural recording and recording of a head-related transfer function (HRTF) can be performed.

  With reference to FIG. 14, the characteristics of the sound wave emitted from the external sound source and detected by the dummy head 1 will be described. FIG. 14 is a graph showing a frequency response characteristic of a sound wave 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 a speaker placed approximately 1000 mm away from the dummy head 1 at the front, and a sound wave was detected by the ear simulator 4 to measure the sound pressure response. At this time, as shown in FIG. 6A, the fixing of the ear simulator 4 by the thumb screw 6 has been 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 without the ear member 24 attached. A waveform W14 indicates 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 have changed due to the mounting of the ear member 24.

  A waveform W15 indicates a 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. The 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 closed by the clay. In each case, a decrease in the sound pressure level was recognized in the high frequency range, but the result was that the sound pressure level hardly changed in the low frequency range.

  The 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 collecting member 42 of the ear simulator 4 is effectively shielded by the sound insulating member 120 of the earplug 100, and the sound pressure level is reduced to about the same level as the bar B2 corresponding to the background noise.

  The embodiments of the invention have been described with reference to examples. However, the present invention is not limited to these specific examples. That is, those specifically modified by those skilled in the art to these specific examples are also included in the scope of the present invention as long as they have the features of the present invention. The components included in each of the above-described specific examples and the arrangement, material, condition, shape, size, and the like thereof are not limited to those illustrated, and can be appropriately changed.

  For example, a passage corresponding to a human nostril may be formed in the nose of the dummy head 1. By communicating the inside and outside of the housing 2 with the passage, the sound quality adjustment range can be expanded, and the effective aperture 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 collecting port 51: cylindrical portion 53: vibration isolating member 83a, 83b: Glass wool (sound absorbing material)
100: earplug 110 rod-shaped member 111: recess 120: sound insulation member 130: connecting part

Claims (7)

A dummy head for detecting voice,
A housing having a space formed therein,
An ear simulator that is arranged in the space and has a sound collection port, and detects sound waves that have been taken from the sound collection port and passed through the waveguide ,
And a vibration damping member for attenuating vibration,
The housing is formed with a passage communicating the outside of the housing and the space,
The sound collection port of the ear simulator is arranged to capture sound waves arriving from the outside of the housing via the passage,
The dummy head, wherein the ear simulator is fixed to the housing via the vibration isolating member. A cylindrical member that is disposed in the space, has a bottomed cylindrical shape, and is fixed to the housing so that the inside communicates with the outside of the housing via the passage,
2. The dummy head according to claim 1, wherein the ear simulator is disposed inside the tubular member, and is supported by the tubular member via the vibration isolating member. 3.   The dummy head according to claim 2, further comprising: a fixing member capable of fixing the ear simulator to the cylindrical member and releasing the fixing. A speaker arranged in the space and generating a sound wave by vibrating a diaphragm,
The housing is formed with a lip opening for communicating the outside of the housing and the space,
4. The dummy head according to claim 3, wherein the speaker is arranged to cover at least a part of the lip opening from the space side. With a plate with a through hole formed,
A first space that is a portion that communicates the space with the outside of the housing via the lip opening by fixing a peripheral portion of the plate to an inner surface of the housing; Is divided into a second space 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 dummy head according to claim 4, wherein the tubular member and the ear simulator are arranged in the second space.   The dummy head according to claim 5, wherein a sound absorbing material is provided in the second space. The dummy head according to claim 1, wherein the sound collection port is shielded by inserting earplugs into the passage.