JP6688241B2 - Dummy head - Google Patents

Description

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

  The human ear perceives sound by receiving a sound wave that is diffracted and reflected in a complicated manner by the pinna and the like. By receiving a sound wave affected by the pinna and the like with a microphone, recording the sound wave as it is, and reproducing the sound wave, a listener can perceive a sound having a more three-dimensional effect. That is, the listener can feel that he or she is listening to a sound close to the original sound.

  Recording / playback in which the influence of the pinna and the like is reflected is called binaural recording / playback, and is performed using, for example, a dummy head described in Patent Document 1. The dummy head has a casing imitating a human head, and a protrusion imitating an auricle and a passage imitating the external auditory meatus are formed in the casing. Further, an ear simulator having a microphone is arranged at a part corresponding to the inner ear of a human.

  Such a dummy head is a head that conforms to the actual human head (hereinafter also referred to as the "real head") by receiving sound waves that have been diffracted / reflected by the housing and protrusions and have passed through the passage with an ear simulator. The head-related transfer function (HRTF) can be measured. Binaural recording is possible by convolving the head-related transfer function or the head-related impulse response (HRIR) obtained by performing an inverse Fourier transform of the head-related transfer function into a signal.

JP-A-5-153687

  Since the dummy head is equipped with the speaker, it can have not only the function of measuring the head-related transfer function and the head-related impulse response but also the function of vocalization. In the dummy head, a speaker is arranged inside the housing, and an opening is formed in a portion corresponding to the lip of the housing. When the speaker generates a sound wave, the sound wave is emitted to the outside through the opening.

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

  However, the size of the opening that can be formed in the housing is extremely narrow, about 20 mm × 40 mm, which corresponds to the lip of a human. Therefore, the inventor of the present application cannot pass the sound wave through the narrow opening, and repeats the reflection in the space inside the housing, or the sound wave is multiple-reflected between the speaker and the inner surface of the housing. I faced the challenge of changing. As a result, the sound perceived by the listener will be significantly different from the original sound.

  As a solution to the above problem, an approach of enlarging the size of the opening is considered in order to allow the sound waves to pass efficiently. However, compared with an actual human lip, the opening becomes unnaturally large, impairing the design, and a new problem arises that the sound wave is emitted from a position different from that of the human lip.

  The present invention has been made in view of the above problems, and an object thereof is to provide a dummy head capable of emitting sound outside while suppressing alteration, and earplugs attached to the dummy head. .

  One embodiment of the present invention for solving the above-mentioned problems is a dummy head that emits sound to the outside, and a housing in which a space is formed, and a vibration plate that is arranged in the space and vibrates a sound wave to generate a sound wave. And a speaker for generating. The case has a lip opening that communicates the outside of the case with the space. The speaker is arranged so as to cover at least a part of the lip opening from the space side and form a gap between the peripheral portion of the speaker and the inner surface of the housing. The size of the gap is at least 1 mm and at most 10 mm.

  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 through the lip opening to the outside. It The remaining portion that cannot directly pass through the lip opening is reflected by the space formed between the inner surface of the housing 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. Therefore, the sound wave reflected in the space formed between the inner surface of the housing 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, it is possible to reduce the multiple reflection of the sound wave in the space, and suppress the alteration of the sound and emit the sound from the lip opening.

  Further, the size of the gap is at least 1 mm and at most 10 mm. This makes it possible to suppress multiple reflections and resonances of the sound waves propagated in the gap, and reduce peaks (dips) and dips (valleys) generated in the frequency response characteristics of the sound.

  The dummy head includes a plate having a through hole formed therein, and the plate has a peripheral edge portion fixed to the inner surface of the housing so that the space communicates with the outside of the housing through the lip opening. The speaker is divided into a first space that is a part and a second space that is the 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 plate may divide the first space into a radial space formed on the lip opening side of the diaphragm and a surplus space formed on the side of the diaphragm.

  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, the sound waves generated by the speaker can be efficiently emitted to the outside. Furthermore, it is possible to suppress the situation where the low-range reproduction limit frequency is lowered due to the sound waves emitted 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 of the diaphragm and a surplus space formed on the side of the diaphragm. Accordingly, by guiding the sound wave that is radiated from the speaker to the radiating space and reflected to the surplus space through the gap, it is possible to suppress the sound wave from being radiated from the lip opening. As a result, it is possible to suppress the situation where the low-range reproduction limit frequency falls.

  The plate may be provided with a sound absorbing material at a portion arranged in the surplus space.

  According to this configuration, by adjusting the size of the through hole and the amount of the sound absorbing material, it is possible to reduce the multiple reflection of the sound wave in the surplus space and adjust the frequency response characteristic of the sound wave emitted from the lip opening to the optimum one. 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. Sound waves of low frequency tend to diffract along the curved surface, and sound waves of high frequency tend 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 frequency 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 peaks and dips in the mid-high range of the frequency response characteristic and flatten the frequency response characteristic.

  The lip opening may be shielded by a film-shaped member formed of an acoustically transparent material.

  According to this configuration, it is possible to covert the inside of the housing while allowing sound waves to be emitted through the lip opening. As the film-shaped member, a metal fiber plate, a perforated metal plate with a large aperture ratio, a lattice-shaped grill, or the like can be adopted, but it hides the inside of the lip opening and almost completely transmits sound waves over the entire frequency band. Any material can be used as long as it is a transparent material. Since such a film-like member has a slight sound absorbing property and a sound diffusing property (scattering property) like a diffuser, it can be used for sound quality adjustment and fine adjustment of frequency response characteristics.

  The dummy head is arranged in a space, has a sound collecting port, and includes an ear simulator that detects a sound wave captured from the sound collecting port, and the housing has a passage formed to communicate the outside of the housing with the space. The sound collecting port may be arranged so as to take in a sound wave emitted from the lip opening to the outside of the housing through the passage.

  According to this configuration, a passage imitating the human ear canal is formed in the housing, and the sound wave emitted by the speaker and the detection by the ear simulator are simultaneously performed, so that the sound uttered by the human being can be changed. It is possible to provide a dummy head that can evaluate the influence on hearing. Such a dummy head can be expected to be applied to various purposes such as performance evaluation of a mobile phone in consideration of the influence of speech of a user during a call, development of a hearing aid, and hearing research.

  The dummy head includes a tubular member having a bottomed tubular shape, and a vibration damping member that damps vibrations. The tubular member is disposed in a space, and the inside of the tubular member is a casing through a passage. The ear simulator may be fixed to the housing so as to communicate with the outside, and the ear simulator may be disposed inside the tubular member and supported by the tubular member via the 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. Therefore, the sound waves emitted from the speaker to the space inside the housing are prevented from reaching the ear simulator. As a result, it is possible to configure the ear simulator so as not to detect a sound wave reflected in the space inside the housing, a so-called air-borne sound.

  By the way, sound waves coming from outside the human body and sound waves emitted from the human mouth (self-speaking) reach their ears mainly through two types of routes. The first route is a route in which sound waves propagate in the air and reach the ear. The sound perceived through the route is called "air conduction sound". The second route is a route in which sound waves are propagated by vibrations of solid bodies such as bones, cartilage, and muscles of the head and reach the ears. The sound perceived through the path is called "bone conduction sound".

  Returning to the above configuration, although the tubular member is fixed to the housing, the ear simulator is supported by the tubular member via the vibration isolating member. According to this configuration, even when the speaker vibration is propagated to the plate, the housing, and the tubular member when the speaker generates a sound wave, it is possible to suppress the propagation of the vibration to the ear simulator. Become. As a result, it is possible to eliminate the influence of bone-conducted sound and evaluate only air-conducted sound.

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

  According to this configuration, by fixing the ear simulator to the tubular member using the fixing member, it is possible to propagate vibration from the tubular member to the ear simulator in a solid state. Further, by releasing the fixation of the ear simulator to the tubular member, it is possible to suppress the propagation of vibration from the tubular 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 of reflecting the influence of the bone conduction sound and the state of eliminating the influence of the bone conduction sound. , And can be switched.

  Another aspect of the present invention is an earplug mounted on a dummy head. The earplug includes a rod-shaped member and a sound insulating 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 blocking the sound collecting port of the ear simulator with the sound insulating member, it is possible to eliminate the air-conducted sound and evaluate only the bone-conducted 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 when a protrusion that imitates a human auricle is formed around the passage of the housing, the recess forms a gap between the rod-shaped member and the protrusion to suppress interference between the two. It will be possible. As a result, the earplugs are inserted into the passage of the housing at an appropriate angle (that is, the angle at which the central axis of the earplugs coincides with the central axis of the passage), and the sound insulation member ensures the sound collection port of the ear simulator. It becomes possible to shield.

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

  With this configuration, when the earplug is inserted into the passage of the housing, it is possible to prevent the site to which the sound insulation member is connected from being caught in the passage.

  According to the present invention, it is possible to provide a dummy head capable of emitting sound outside while suppressing deterioration, and earplugs attached to the dummy head.

FIG. 3 is a perspective view showing an appearance of a dummy head according to the 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. FIG. 3 is an enlarged view of the vicinity of the lip portion of FIG. 2. It is explanatory drawing explaining the fixed state of an ear simulator. It is an enlarged view of the vicinity of the lip of the dummy head. It is a perspective view of the earplug concerning an embodiment. It is an enlarged view which shows the dummy head which attached the earplug. It is a graph which shows the frequency response characteristic of the sound wave emitted from the lip opening of a dummy head. It is a graph which shows the frequency response characteristic of the sound wave emitted from the lip opening of a dummy head. It is a graph which shows the frequency response characteristic of the sound wave detected by the ear simulator of a dummy head. It is a graph which shows the frequency response characteristic of the sound wave detected by the ear simulator of a dummy head. It is a graph which shows the frequency response characteristic of the sound wave detected by the ear simulator of a dummy head.

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

  An 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 simulating 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.

  A protrusion that imitates a human nose is formed on the front surface of the housing 2. Further, a lip portion 25 simulating 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 connects the outside of the housing 2 and a space 20 inside the housing 2 described later. The lip opening 25a has a vertical dimension of about 20 mm and a horizontal dimension of about 40 mm.

  The lip opening 25a is shielded by a blindfold cover 26 which is a film-shaped member made of an acoustically transparent 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 adopted. The blind cover 26 has almost 100% acoustic transparency over a frequency band of 20 Hz-20 kHz. The blind cover 26 also has a sound absorbing property, although it is slightly. Therefore, the blind cover 26 can be used together with the sound absorbing material 82 described later for adjusting the quality of the sound emitted from the lip opening 25a and the frequency response characteristic.

  An ear member 24 imitating a human ear is attached to a side surface portion 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 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 projects outward from the base portion 24a. The auricle 24b functions as a sound collector for sound waves coming from the outside, like the human auricle. A passage 24c simulating an external auditory meatus is formed inside the auricle portion 24b. The passage 24c penetrates the base portion 24a.

  Further, the side surface of the housing 2 is formed with a recess 23 into which the base 24a of the ear member 24 is mounted. The base 24a is mounted in the recess 23 without any gap. An ear simulator 4 to be described later is arranged inside the recess 23.

  Next, the configuration of the dummy head 1 will be described in detail with reference to FIGS. 2 to 7. FIG. 2 is a cross-sectional view showing a II-II cross section of FIG. 1. FIG. 3 is a cross-sectional view showing a III-III cross section of FIG. 2. 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. 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 portion 25 of FIG. FIG. 6 is an explanatory diagram illustrating a fixed state of the ear simulator 4. FIG. 7 is an enlarged view of the vicinity of the lip portion 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. Further, the diffuser 7 is arranged 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 function part 32. The functional unit 32 accommodates various elements such as coils and magnets that function based on control signals. When the function part 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 protruding portions 372. The four protrusions 372 are formed so as to protrude from the central portion of the annular portion 371 toward one side. The ends of the four projecting protrusions 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 protrusion 372. Further, on one side surface of the annular portion 371, around the protruding portion 372, glass wool 81 formed of glass fiber is attached. The glass wool 81 functions as a sound absorbing material. The speaker 3 is fixed to the plate 37 by inserting the functional portion 32 into the through hole 37a and adhering it to the adhesive 37b.

  As shown in FIGS. 2 and 3, the plate 37 is arranged in a portion of the space 20 of the housing 2 near the lip opening 25a, and its peripheral edge is fixed to the inner surface 20a of the housing 2. . As a result, 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 via the lip opening 25a. The diaphragm 31 of the speaker 3 is arranged in the first space 21. Clay or putty material (not shown) is filled between the peripheral edge of the plate 37 and the inner side 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 radiates a sound wave into the radiation space 21 a by vibrating the diaphragm 31. The extra 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 protruding portions 372, and the inner side surface 20a of the housing 2.

  Spacers 84 are arranged in the gaps between the four corners of the diaphragm 31 of the speaker 3 and the inner side surface 20 a 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 region 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 directly faced to the speaker 3, the speaker 3 is arranged so that its center 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 made of glass fibers 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. The glass wools 83a and 83b are both made of glass fiber and function as a sound absorbing material.

  The ear simulator 4 is a sound wave detecting device having a microphone, and may be, for example, a device conforming to IEC60268-7 which is a standard of the International Electrotechnical Commission. As shown in FIG. 3, the ear simulator 4 is arranged in the second space 22 at a portion corresponding to the inner ears 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 portion protruding from the main body 41. The sound collecting port 42a provided 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 for example, an electric condenser microphone can be adopted.

  The cap 5 is an aspect of a bottomed tubular member. The cap 5 is made of a resin material, and as shown in FIG. 3, has a tubular portion 51 having a cylindrical shape and a bottom portion 52 that shields one end of the tubular portion 51. The cap 5 is arranged in the second space 22 at portions corresponding to the eardrum, middle ear, and inner ear of both ears, and its open end is fixed to the inner surface 20 a of the housing 2 without a gap. The cylindrical portion 51 has a communication hole 51a through which the signal line 51b is inserted. A rubber tube, a washer, etc. (not shown) are mounted in the gap between the communication hole 51a and the signal line 51b to keep the cap 5 airtight. In addition, a plurality of thumbscrews 6 are screwed into the cylindrical portion 51 at different positions in the circumferential direction. The tip end of the thumbscrew 6 that is screwed in 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 ear simulator 4 described above is arranged inside the cap 5, and is supported by the inner surface of the cap 5 via the vibration isolating member 53. With this arrangement, the ear simulator 4 is isolated from the other parts of the second space 22. The ear simulator 4 is arranged so that the sound collecting ports 42 a of the sound collecting cylinder 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 51b inserted through the communication hole 51a of the tubular 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 24c (see FIG. 1) of the ear member 24.

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

  On the other hand, as shown in FIG. 6B, the ear screw 4 is fixed to the cap 5 by protruding the thumbscrew 6 so that the tip end contacts the main body 41 of the ear simulator 4. . In this state, when the housing 2 and the cap 5 vibrate as shown by the arrow S1, the vibration (that is, bone conduction sound) propagates to the ear simulator 4 by the thumbscrew 6. That is, the vibration isolator 53 cannot damp the vibration, and the vibration propagates to the ear simulator as it is.

  As shown in FIG. 7, the diffuser 7 is arranged inside the lip opening 25a. The diffuser 7 has a spherical body 71 and a rod body 72. The sphere 71 is made 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 72 is made 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 body 72 supports the sphere body 71 so that the sphere body 71 is arranged substantially at the center of the lip opening 25 a and the sphere body 71 does not project 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 made of a hard material such as wood or resin and has a columnar shape. The length of the rod member 110 is about 10 mm to 50 mm. A recess 111 is formed on a part of the outer surface of the rod member 110.

  The sound insulation member 120 is formed of an elastic material such as urethane rubber and is connected to the tip of the rod member 110. The thickness of the sound insulation member 120 is about 1 mm to 5 mm. The sound insulation member 120 has a circular cross section, and its diameter 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 near the portion to which the sound insulation member 120 is connected. The connecting portion 130 is formed of a material such as a putty material or a caulking material that is hardened after molding to have a fixed shape. The connecting portion 130 smoothly connects the outer surface of the sound insulation member 120 and the outer surface of the tip 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, the tragus 24d of the ear member 24 is arranged in the recess 111 of the rod-shaped member 110, so that 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 insulation member 120 collects sound in the ear simulator 4. It is possible to reliably shield 42a.

  Further, as shown in FIG. 8, since the outer surface of the sound insulating member 120 and the outer surface of the tip 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 part to which the sound insulating member 120 is connected is not caught in the passage 24c.

  As shown in FIG. 3, the dummy head 1 can be equipped with not only the earplug 100 but also a commercially available ear muffler 88 or earplug 89. The ear muffler 88 is attached to both sides 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 entrance portion of the passage 24c.

<Voice production by dummy head (sound emission)>
The dummy head 1 has a voicing function that operates as if a human being uttered by emitting the sound wave generated by the speaker 3 to the outside of the housing 2 from the lip opening 25a. As described above, the dummy head 1 having a vocalizing function can be expected to be mounted on a robot or the like, or applied to a security (security) -related device or system.

  The characteristics of the sound waves emitted by the dummy head 1 according to the embodiment will be described with reference to FIGS. 10 and 11. 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 frequency response characteristics of sound waves emitted from the dummy head 1 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 vocalization test performed on the dummy head according to the comparative example and the dummy head 1 according to the embodiment. In the vocalization test, pink noise was applied to the speaker 3 of the dummy head according to the comparative example and the dummy head 1 according to the embodiment, and the sound pressure frequency response characteristic was measured by the external microphone. The external microphone was placed 20 mm forward from the lip opening 25a. The flatter the waveform of the characteristic graph, the more natural the voice tends to be perceived by the listener.

  The waveform W1 in FIG. 10 shows the result of the vocal test performed on the dummy head according to the first comparative example. The dummy head differs 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 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 arranged between the lip opening 25a and the diaphragm 31 of the speaker 3.

  In the dummy head according to the first comparative example as described above, the frequency response characteristic of the sound wave emitted from the lip opening 25a has steep peaks (peaks) and dips (valleys). As a result, the sound perceived by the listener was greatly distorted.

  The waveform W2 in FIG. 10 shows the result of the vocal 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 peripheral edge of the diaphragm 31 and the inner side surface 20a of the housing 2 to eliminate a gap.
[D2] The glass wool 82 is not arranged 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 has a sound pressure level that is generally higher than 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 became even more distorted, and was far from natural utterance. It is considered that the main reason for this is that the sound waves that could not pass through the lip opening 25a were reflected in the space 20 inside the housing 2.

  The waveform W3 in FIG. 10 shows the result of the vocal 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 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. Is set to.

[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 the dummy head according to the third comparative example, the frequency response characteristic of the sound wave emitted from the lip opening 25a is flat as compared with the dummy heads according to the first and second comparative examples. Became. This is because in the dummy head according to the third comparative example, the sound wave reflected in the radiation space 21a is generated at the peripheral edge of the diaphragm 31 and the inner surface 20a of the housing 2 as shown by an arrow A1 in FIG. It is considered that this is caused by being guided to the surplus space 21b through the gap between the two. In other words, it can be considered that by eliminating the multiple-reflected sound waves from the radiation space 21a, the emission to the outside through the lip opening 25a is suppressed.

  Further, 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, so that the sound waves propagated in the gap are multiplexed. The suppression of reflection and resonance is also considered to be a factor.

  The waveform W4 in FIG. 11 shows the result of the vocal test performed on the dummy head according to the fourth comparative example. The dummy head differs 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 arranged 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 as described above, 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 were shown. It is considered that this is because 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.

  The waveform W5 in FIG. 11 shows the result of the vocal test performed on the dummy head according to the fifth comparative example. The dummy head differs 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 plate 37 of the dummy head according to the fourth comparative example.

[A5] The diffuser 7 is not provided.
[B5] The glass wool 82 is not arranged 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 made of aluminum.

  In the dummy head according to the fifth comparative example as described above, the frequency response characteristic of the sound wave emitted from the lip opening 25a has a larger dip than that in the dummy head according to the fifth comparative example. Was given.

  The waveform W6 in FIG. 11 shows the result of the vocal 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 became flatter. As a result, the sound perceived by the listener became less distorted. It is considered that this is because the glass wool 81 attached to the plate 37 suppressed the reflection of sound waves in the first space 21 and adjusted the frequency response characteristics of the sound waves emitted from the lip opening 25a.

  Further, the sound wave passing through the lip opening 25a is diffracted on the outer surface of the spherical body 71 of the diffuser 7 and is emitted to the outside of the housing 2 while changing its directivity. Sound waves having a low frequency tend to be diffracted along the curved surface, and sound waves having a high frequency tend to be diffused 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 to be a factor.

  Further, in the dummy head 1, glass wool 82, which is a sound absorbing material, is arranged between the lip opening 25a and the diaphragm 31 of the speaker 3. With this configuration, multiple reflection and resonance of sound waves 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 can be considered that the fact that the frequency response characteristic of the sound wave emitted from the lip opening 25a has become flat.

<Voice production and listening by the dummy head (sound emission and reception)>
The dummy head 1 has a listening function of receiving a sound wave by the ear simulator 4 in addition to the vocalizing function described above. As described above, the dummy head 1 capable of simultaneously speaking and listening can be used for the performance evaluation of a mobile phone in consideration of the influence of speech of the user during a call, the development of a hearing aid, a research area on hearing and self-speaking, etc. It can be expected to be applied to various purposes.

  With reference to FIG. 12 and FIG. 13, the characteristics of the sound waves that the dummy head 1 radiates to the outside and is received and detected by its own ear simulator (that is, the characteristics of self-speaking listening) will be described. At the same time, the effect of the earplug 100 will be described. 12 and 13 are graphs showing frequency response characteristics of sound waves detected by the ear simulator 4 of the same dummy head 1 to which 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 the self-utterance listening test performed on the dummy head 1. In the self-utterance 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 characteristic indicated by the bar B1 in FIGS. 12 and 13 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 lower than that of the rod B1.

  FIG. 12 shows the result of the self-utterance listening test in a state where the ear simulator 4 is not fixed by the thumbscrew 6 as shown in FIG. 6 (A). In this state, the vibration damping member 53 damps the vibration, so that the propagation of the 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 is detected by the ear simulator 4 as indicated by arrow A2. As a result, the influence of bone-conducted sound can be eliminated and only air-conducted sound can be evaluated.

  The waveform W7 in FIG. 12 shows the result of the self-utterance listening test performed on the dummy head 1 in a state where the ear member 24 is not attached. Further, the waveform W8 shows the result of the 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 wearing of the ear member 24.

  A waveform W9 in FIG. 12 shows the result of the 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 the 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 the commercially available earplug 89. In all cases, the sound pressure level decreased 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-speaking when a finger is put into the ear hole, and suggests that it is necessary to pay attention to the utterance with the earplugs attached.

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

  The waveform W11 has an increase in sound pressure level of about 20 dB as compared with the waveform W12. This is because, in the waveform W11, the ear simulator 4 is fixed by the thumbscrew 6, 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 noisy. 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-conducted sound in the real head.

<Listen to external sound by the dummy head (receive sound wave)>
The dummy head 1 can also enable only the listening function and listen to only external sound. By detecting a sound wave that reaches from the outside by the ear simulator 4, for example, it is possible to perform binaural recording or recording of a head-related transfer function (HRTF).

  With reference to FIG. 14, characteristics of sound waves emitted from an 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 the listening test performed on the dummy head 1. In the listening test, pink noise was applied to a speaker arranged at a position approximately 1000 mm forward from the dummy head 1, 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 fixation of the ear simulator 4 by the thumb screw 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 lower than that of the rod B2.

  A waveform W13 shows the result of the listening test performed on the dummy head 1 in a state where the ear member 24 is not attached. The waveform W14 shows the result of the 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 wearing of the ear member 24.

  The waveform W15 shows the result of the listening test performed on the dummy head 1 in a state where the ear member 24 is covered with the ear muffler 88. Further, the waveform W16 shows the result of the listening test performed on the dummy head 1 in a state where the passage 24c of the ear member 24 is blocked by clay. In each case, the sound pressure level was found to decrease in the high frequency region, but the sound pressure level hardly changed in the low frequency region.

  A waveform W17 shows the result of the hearing test performed on the dummy head 1 with the earplug 100 inserted in the passage 24c of the ear member 24. It can be seen that the sound insulation member 120 of the earplug 100 effectively shields the sound collection port 42a of the ear simulator 4, 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. That is, those obtained by appropriately modifying the design of these specific examples by those skilled in the art are also included in the scope of the present invention as long as they have the features of the present invention. The elements provided in each of the above-described specific examples and the arrangement thereof, the material, the condition, the shape, the size, and the like 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 portion 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 widened, 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 (cylindrical member)
6: Thumb screw (fixing member)
7: Diffuser 20: Space 21: First space 22: Second space 24c: Passage 25a: Lip opening 31: Vibration plate 37: Plate 37a: Through hole 42a: Sound collecting port 51: Cylindrical part 53: Vibration damping member 81: Glass wool (sound absorbing material)
82: Glass wool (sound absorbing material)
100: Earplug 110 Rod-shaped member 111: Recess 120: Sound insulation member 130: Connection part

Claims (9)

A dummy head that emits sound outside,
A case with a space formed inside,
A speaker arranged in the space for generating a sound wave by vibrating a diaphragm,
The casing has a lip opening that communicates the outside of the casing with 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 a peripheral portion of the speaker and an inner side surface of the housing,
The dummy head, wherein the size of the gap is at least 1 mm and at most 10 mm. Equipped with a plate with through holes,
The plate has a first space that is a portion that communicates the space with the outside of the housing through the lip opening by fixing the peripheral portion of the plate to the inner surface of the housing, and the remaining portion It is divided into the second space which is
The speaker is inserted into the through hole and is fixed to the plate so that the diaphragm is arranged in the first space,
The said plate divides the 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, The said 1st space | interval. Dummy head.   The dummy head according to claim 2, wherein the plate includes a sound absorbing material in a portion arranged in the surplus space. The dummy head according to claim 2, wherein the radiation space is provided with a sound absorbing material. The dummy head according to any one of claims 1 to 4, wherein a diffuser having an outer surface formed of a curved surface is provided in the lip opening.   The dummy head according to any one of claims 1 to 5, wherein the lip opening is shielded by a film-shaped member formed of an acoustically transparent material. Arranged in the space, having a sound collecting port, equipped with an ear simulator for detecting sound waves captured from the sound collecting port,
The casing has a passage formed therein to communicate the outside of the casing with the space,
The dummy head according to any one of claims 1 to 6, wherein the sound collecting port is arranged so as to take in a sound wave emitted from the lip opening to the outside of the housing through the passage. . A tubular member having a bottomed tubular shape,
A vibration damping member for damping vibration,
The tubular member is arranged in the space, is fixed to the housing so that the inside of the tubular member communicates with the outside of the housing through the passage,
The dummy head according to claim 7, wherein the ear simulator is arranged inside the tubular member and is supported by the tubular member via the vibration isolating member.   The dummy head according to claim 8, further comprising a fixing member capable of fixing the ear simulator to the tubular member and releasing the fixation.