Ear-insertion-type sound collection device

Abstract

This ear-insertion-type sound collection device comprises: an ear tip part that is held on an ear canal wall; and a microphone holding part that is positioned closer to the eardrum than the ear tip part and holds a microphone. The microphone is held by the microphone holding part such that a sound collection surface faces toward the eardrum.

Description

in-ear sound pickup device

[0001] The present technology relates to an in-ear sound collecting device that is inserted into the ear when used.

[0002] In order to realize various types of acoustic signal processing for earphones and headphones, such as acoustic signal processing as noise canceling (NC) processing, various types of sound quality correction, and acoustic signal processing for sound field reproduction, the transfer characteristics of an audio transmission system including the ear canal (the audio transmission system up to the eardrum) are measured. When measuring the transfer characteristics of an audio transmission system including the ear canal, a measurement microphone is placed inside the ear canal (see, for example, Patent Document 1 below).

[0003] International Publication No. 2020 / 021815

[0004] The above-mentioned Patent Document 1 describes that the sound collection surface (sound input hole) of the measurement microphone is arranged facing away from the eardrum.

[0005] In a small microphone placed inside the ear canal, the microphone cable is drawn out from the opposite side of the sound collection surface, not toward the sound collection surface. Therefore, if the sound collection surface is oriented away from the eardrum, as in Patent Document 1, the microphone cable is routed further out than the microphone. When the in-ear sound collection device is worn, the microphone cable is exposed inside the ear canal, potentially impeding sound propagation within the ear canal. This can potentially reduce the accuracy of transfer function measurements.

[0006] Furthermore, if the microphone cable is routed further outward than the microphone as described above, the microphone cable may rub against the wall of the ear canal when the in-ear sound collection device is worn, causing pain to the wearer.

[0007] The present technology has been developed in consideration of the above circumstances, and aims to improve the measurement accuracy of the transfer characteristics of an in-ear type sound collection device while preventing pain when worn.

[0008] The in-ear sound collection device according to the present technology includes an eartip portion that is held against the ear canal wall, and a microphone holding portion that is positioned closer to the eardrum than the eartip portion and holds a microphone, the microphone being held in the microphone holding portion so that its sound collection surface faces the eardrum. Since the sound collection surface faces the eardrum, the microphone cable can be routed to the side opposite the eardrum, and the microphone cable can be routed inside the eartip portion rather than around the microphone. This prevents the microphone cable from appearing inside the ear canal when the in-ear sound collection device is worn, and also prevents the microphone cable from rubbing against the ear canal wall when worn.

[0009] 1 is an explanatory diagram of an example of sound field reproduction assumed in an embodiment. FIG. 2 is an explanatory diagram of an example of transfer characteristics to be measured in order to realize the sound field reproduction of FIG. 1. FIG. 3 is an external perspective view of an in-ear sound collection device according to a first embodiment of the present technology. FIG. 4 is a cross-sectional view of the in-ear sound collection device according to the first embodiment. FIG. 5 is a cross-sectional view of the in-ear sound collection device with an earphone inserted in the earphone insertion portion. FIG. 6 is a perspective view showing an external example of an in-ear sound collection device when the number of legs is two. FIG. 7 is an external perspective view of an in-ear sound collection device according to a second embodiment. FIG. 8 is an external perspective view of a playback earpiece according to an embodiment. FIG. 9 is a cross-sectional view of a playback earpiece according to an embodiment. FIG. 10 is an explanatory diagram of an example in which the microphone holding portion is tilted obliquely. FIG. 11 is an explanatory diagram of an example in which a coil-shaped microphone holding portion is used. FIG. 12 is an explanatory diagram of an example in which a mesh portion is formed on the sound collection surface. FIG. 13 is an explanatory diagram of an example in which a mesh portion is formed in a sound emitting opening between the legs. FIG. 14 is an explanatory diagram of an example in which a mesh portion is formed in a through-hole in the eartip portion. FIG. 15 is an explanatory diagram of an example in which a mesh portion is formed midway along the sound propagation path from the earphone insertion portion to the sound emitting opening. FIG. 16 is an explanatory diagram of a modified example relating to the wiring of a microphone cable. FIG. 17 is an explanatory diagram of another modified example relating to the wiring of a microphone cable. FIG. 10 is an explanatory diagram of a modified example of the leg portion.

[0010] Hereinafter, embodiments of the present technology will be described in the following order: <1. Sound field reproduction and transfer characteristics assumed in the embodiments> <2. In-ear sound collection device as a first embodiment> [2-1. Configuration example] [2-2. Summary of the first embodiment] <3. In-ear sound collection device as a second embodiment> [3-1. Configuration example] [3-2. Summary of the second embodiment] <4. Examples of playback ear inserts> <5. Modified examples> <6. The present technology>

[0011] 1. Sound Field Reproduction and Transfer Characteristics Assumed in the Embodiments> Fig. 1 is an explanatory diagram of an example of sound field reproduction as a premise of the embodiments. This embodiment is premised on sound field reproduction that allows a listener wearing earphones to perceive a virtual speaker sound source as indicated by the dashed line in the figure. Specifically, the aim is to achieve sound field reproduction that provides a listening experience as if the listener were directly listening to sound produced by a speaker, even when wearing earphones. The earphones referred to here refer to in-ear type earphones.

[0012] Fig. 2 is an explanatory diagram of an example of transfer characteristics to be measured to realize the sound field reproduction of Fig. 1. To realize the sound field reproduction of Fig. 1, a transfer function S_HRTF indicating the transfer characteristics of sound from the speaker to the ear canal (eardrum) as shown in Fig. 2A and a transfer function E_TF indicating the transfer characteristics of sound from the earphone to the ear canal (eardrum) as shown in Fig. 2B are measured. Here, TF is an abbreviation for "Transfer Function" and HRTF is an abbreviation for "Head-Related Transfer Function."

[0013] The transfer function S_HRTF in Fig. 2A is measured based on the picked-up signal obtained by collecting sound from a speaker with a microphone ("Mic" in the figure) placed in the ear canal. The transfer function E_TF in Fig. 2B is measured based on the picked-up signal obtained by collecting sound reproduced by the earphone with the microphone placed in the ear canal and the earphone being worn.

[0014] If the transfer function E_TF from the earphone to the ear canal can be ignored, convolving the transfer function S_HRTF with the acoustic signal would allow for sound field reproduction as shown in Figure 1 , but in reality, the transfer function E_TF is convolved with the acoustic signal. That is, in this case, sound field reproduction involves convolving the transfer function S_HRTF with the acoustic signal while performing a calculation that cancels the transfer function E_TF. Specifically, the filter F used for sound field reproduction is created as follows: F = S_HRTF x 1 / E_TF. When reproducing acoustic signal A, a convolution calculation "A x F" is performed using this filter F. This allows for sound field reproduction that sounds as if the sound from the speaker is being heard directly, as described in Figure 1 .

[0015] In this case, earphones are used as the sound reproduction device for reproducing the sound field, so the listener can experience the sound field to be reproduced even if they are not present at the venue. Also, even if they are wearing earmuffs or NC (noise canceling) headphones to block out external sounds, they can experience the sensation of listening to sound from speakers.

[0016] For clarity, the transfer functions S_HRTF and E_TF should be measured for each of the left and right ears for each sound source to be reproduced. For example, if sound sources from two left and right speakers are to be reproduced, the transfer functions S_HRTF and E_TF should be measured for a total of four combinations: a pair of an Lch (left channel) speaker and the left ear, a pair of an Lch speaker and the right ear, a pair of an Rch (right channel) speaker and the left ear, and a pair of an Rch speaker and the right ear.

[0017] Furthermore, sound field reproduction is not limited to reproduction of a sound field produced by a speaker as described above, but may be reproduction of a sound field produced by a sound source other than a speaker, or reproduction of a sound field based on binaural recording, as long as it reproduces a three-dimensional acoustic space.

[0018] 2. In-ear sound collection device as a first embodiment> [2-1. Configuration example] An in-ear sound collection device 1 as a first embodiment will be described with reference to Fig. 3 and Fig. 4. The in-ear sound collection device 1 as the first embodiment is an in-ear sound collection device used to measure the transfer function E_TF out of the transfer functions S_HRTF and E_TF described above.

[0019] Fig. 3 is an external perspective view of the in-ear sound collection device 1, and Fig. 4 is a cross-sectional view of the in-ear sound collection device 1. Here, the following description illustrates a case where the in-ear sound collection device according to the embodiment is designed in a shape based on a circle, but this is merely one example, and designs based on shapes other than a circle, such as a design based on an oval shape or a polygonal shape such as an octagon or hexagon, can also be used.

[0020] In addition, in this specification, directions related to the in-ear sound collection device are defined as follows: Since the device is expected to be inserted into the ear canal when used, the side closest to the eardrum when inserted is defined as the tip side, and the opposite side is defined as the exterior side, with the direction from the exterior side to the tip side being defined as the vertical direction, and the direction perpendicular to the vertical direction being defined as the horizontal direction.

[0021] The in-ear sound collection device 1 includes a microphone 2, an eartip portion 3 that is held on the wall of the ear canal, and a microphone holding portion 4 that is positioned further distal (towards the eardrum) than the eartip portion 3 and holds the microphone 2.

[0022] The eartip portion 3 has a roughly bowl-shaped outer shape and is formed so that its width narrows toward the tip. The eartip portion 3 has an outer wall portion 3a and an inner wall portion 3b. The outer wall portion 3a is the portion whose outer surface comes into contact with the wall of the wearer's ear canal when the earplug-type sound collection device 1 is worn, and the inner wall portion 3b is the portion located on the inner periphery of the outer wall portion 3a and formed in a roughly cylindrical shape. A gap is provided between the inner wall portion 3b and the outer wall portion 3a.

[0023] The gap on the inner periphery of inner wall 3b is formed as earphone insertion section 6. Earphone insertion section 6 has an earphone hole He into which part of earphone 50 can be inserted. Earphone insertion section 6 also has a locking section 6a formed therein for locking part of earphone 50. In this example, locking section 6a is formed as an uneven section formed on the inner periphery of inner wall 3b.

[0024] 5 is a cross-sectional view of the in-ear sound collection device 1 with an earphone 50 inserted into the earphone insertion section 6. The tip portion of the earphone 50, where the sound outlet 50a is formed, is inserted into the earphone insertion section 6, and the tip portion is locked by the locking section 6a, thereby maintaining the earphone 50 attached to the in-ear sound collection device 1.

[0025] As shown in Fig. 4 , an earphone hole He penetrates vertically inside the inner circumferential wall 3b of the eartip portion 3. As shown in Fig. 5 , when the earphone 50 is attached to the earphone insertion portion 6, the sound outlet 50a of the earphone 50 communicates with the earphone hole He.

[0026] 3 and 4, the microphone holder 4 has a microphone insertion hole Hm formed in the inner periphery thereof, and holds the microphone 2 inserted into this microphone insertion hole Hm.

[0027] The microphone 2 is configured with two opposing end faces, one of which is formed as a sound collection surface 2a, and a microphone cable 2b extending from the other end face. The sound collection surface 2a is the surface on which the diaphragm is disposed. The microphone cable 2b is a wiring cable for transmitting the sound collection signal by the microphone 2, i.e., an electrical signal indicating the vibration mode of the diaphragm.

[0028] In this example, the microphone 2 specifically has a substantially cylindrical outer shape, and one of the two circular end faces is formed as the sound collection surface 2 a. Corresponding to the microphone 2 having a substantially cylindrical outer shape, the microphone insertion hole Hm in this case is formed as a substantially cylindrical hole that passes through the microphone holding portion 4 in the vertical direction.

[0029] In the in-ear sound collection device 1 of this embodiment, the microphone 2 is held by the microphone holder 4 so that the sound collection surface 2a faces the eardrum. In this example, the microphone 2 is held by the microphone holder 4 so that the sound collection surface 2a is perpendicular to the central axis of the in-ear sound collection device 1, and when the in-ear sound collection device 1 is worn, the sound collection surface 2a faces the eardrum.

[0030] As described above, by orienting the sound collection surface 2a toward the eardrum, it is possible to pull out the microphone cable 2b on the side opposite the eardrum, and it is possible to route the microphone cable 2b inside the eartip portion 3 as in the example described below, rather than routing it around the microphone 2 or the microphone holding portion 4. This makes it possible to prevent the microphone cable 2b from appearing inside the ear canal when the in-ear sound collection device 1 is worn, and also prevents the microphone cable 2b from rubbing against the wall of the ear canal when worn. Therefore, it is possible to improve the measurement accuracy of the transfer characteristics of the in-ear sound collection device 1 while preventing pain when worn.

[0031] In this example, a cable insertion opening Mc for inserting the microphone cable 2b is formed in the eartip portion 3 at a position outside the earphone insertion portion 6. Specifically, in this example, the cable insertion opening Mc is formed on the tip surface of the eartip portion 3, i.e., the end surface on the eardrum side, at a position outside the inner wall portion 3b and inside the outer wall portion 3a. By forming such a cable insertion opening Mc, the microphone cable 2b is prevented from being routed outside the eartip portion 3.

[0032] In this example, the eartip portion 3 is formed with a tunnel portion 8 having an insertion hole portion Hc that communicates with the cable insertion opening Mc. The insertion hole portion Hc is a hole extending in the vertical direction and communicates with the cable insertion opening Mc, so in this example, the tunnel portion 8 extends in the vertical direction between the outer wall portion 3 a and the inner wall portion 3 b. In this example, the tunnel portion 8 is formed integrally with the inner wall portion 3 b. This tunnel portion 8 holds the microphone cable 2 b that is inserted from the cable insertion opening Mc to the insertion hole portion Hc. As shown in FIG. 4 , the microphone cable 2 b inserted through the insertion hole portion Hc is wired to the outside of the in-ear sound pickup device 1 via the gap between the outer wall portion 3 a and the inner wall portion 3 b.

[0033] By forming the tunnel portion 8 as described above, it is possible to reduce the amount of sound leakage that occurs when sound emitted from the earphone 50 leaks out of the ear through the cable insertion opening Mc.

[0034] Regarding the tunnel portion 8, the effect of reducing sound leakage tends to increase as the length of the insertion hole portion Hc increases. The structure of the tunnel portion 8, including the penetration direction of the insertion hole portion Hc, is not limited to the above example.

[0035] Here, in the in-ear sound collection device 1 of this embodiment, the maximum width of the microphone holding portion 4 is narrower than the width of the tip of the eartip portion 3. Specifically, in this example, the microphone holding portion 4 is arranged coaxially with the eartip portion 3, and the maximum diameter of the microphone holding portion 4 is smaller than the diameter of the tip of the eartip portion 3. By making the microphone holding portion 4 narrower than the eartip portion 3, it is possible to make it easier to insert the eartip portion 3 into the ear canal.

[0036] In the in-ear sound collection device 1 of this embodiment, the microphone holding part 4 has a main body part 4a and a tip part 4b, and as shown in the figure, the tip part 4b is formed in a tapered shape, which alleviates pain when the tip of the microphone holding part 4 comes into contact with the wall of the ear canal when the in-ear sound collection device 1 is worn.

[0037] In the in-ear sound collection device 1 of this embodiment, the microphone holding portion 4 is connected to the eartip portion 3 via a plurality of legs 5. In this example, three legs 5 are provided and are arranged at equal intervals in the circumferential direction. The number of legs 5 is not limited to three, and can be, for example, two or four or more.

[0038] In the in-ear sound collection device 1 of this embodiment, the gap between the legs 5 is formed as a sound emission opening Ms, and sound emitted from the earphone 50 can be transmitted to the internal space of the ear canal through this sound emission opening Ms.

[0039] To explain the specific configuration, in the in-ear sound collection device 1 of this example, the microphone holding portion 4 is connected to the eartip portion 3 not only by the multiple legs 5 but also by an inner cylindrical portion 7 formed on the inner periphery of these legs 5. In this example, the inner cylindrical portion 7 is formed as a portion in which the inner wall portion 3b of the eartip portion 3 extends toward the tip, and a gap portion that communicates with the earphone hole He is formed on the inner periphery. The inner cylindrical portion 7 has multiple through-holes that penetrate laterally and are arranged circumferentially, and these through-holes form the earphone opening Me.

[0040] In the in-ear sound collection device 1 of this example, the earphone opening Me formed in the inner cylindrical portion 7 and the sound emitting opening Ms formed between the leg portions 5 are connected in this manner, so that when the in-ear sound collection device 1 is worn, sound emitted from the earphone 50 is propagated into the internal space of the ear canal via the earphone hole He, the earphone opening Me, and the sound emitting opening Ms.

[0041] The configuration for propagating the sound emitted from the earphone 50 into the internal space of the ear canal is not limited to the above, and other configurations may be considered, such as a configuration in which the inner cylindrical portion 7 is omitted.

[0042] In the present example, all parts of the in-ear sound collection device 1 except for the microphone 2 and microphone cable 2b, namely the eartip part 3, microphone holding part 4, multiple legs 5, and inner tube part 7, are integrally formed from an elastic material such as silicone or resin.

[0043] [2-2. Summary of the First Embodiment] As described above, the in-ear sound collection device (1) of the first embodiment includes an eartip portion (3) that is held against the ear canal wall, and a microphone holding portion (4) that is positioned closer to the eardrum than the eartip portion and holds a microphone (2). The microphone is held in the microphone holding portion so that its sound collection surface (2a) faces the eardrum. By facing the sound collection surface toward the eardrum, the microphone cable can be routed to the side opposite the eardrum, allowing the microphone cable to be routed inside the eartip portion rather than around the microphone. This prevents the microphone cable from protruding into the ear canal when the in-ear sound collection device is worn, and also prevents the microphone cable from rubbing against the ear canal wall when worn. Therefore, the in-ear sound collection device can improve the accuracy of transfer characteristic measurements while preventing pain during wear.

[0044] In addition, in the in-ear sound collection device of the first embodiment, the maximum width of the microphone holding portion is narrower than the width of the tip of the eartip portion. By making the microphone holding portion narrower than the eartip portion, it is possible to easily insert the eartip portion into the ear canal. This improves the wearability of the in-ear sound collection device.

[0045] Furthermore, in the in-ear sound collection device of the first embodiment, the tip of the microphone holding part is tapered. This reduces pain when the tip of the microphone holding part comes into contact with the wall of the ear canal when wearing the in-ear sound collection device. Therefore, the wearing comfort of the in-ear sound collection device can be improved.

[0046] Furthermore, in the in-ear sound collection device of the first embodiment, an earphone insertion section (6) into which an earphone (50) is inserted is formed on the inner periphery of the eartip section. This makes it possible to realize an in-ear sound collection device for measuring the transfer function E_TF (an in-ear sound collection device for measuring earphone and ear canal transfer characteristics) that can collect sound propagated into the ear canal using the earphone as a sound source.

[0047] Furthermore, the in-ear sound collection device of the first embodiment has a sound output opening (Ms) between the microphone holder and the eartip that communicates with the earphone insertion section. This sound output opening allows the earphone insertion section to communicate with the internal space of the ear canal, allowing sound from the earphone to be efficiently transmitted to the ear canal. This allows for appropriate measurement of the transfer function E_TF.

[0048] Furthermore, the in-ear sound collection device of the first embodiment is formed with multiple legs (5) that connect the microphone holding portion to the eartip portion. With this configuration, the earphone insertion portion can communicate with the internal space of the ear canal through the sound release opening formed between the multiple legs, allowing sound from the earphone to be efficiently transmitted to the ear canal. Furthermore, the multiple legs enhance the support force of the microphone holding portion. Therefore, while achieving appropriate measurement of the earphone and ear canal transfer characteristics, the risk of malfunction, such as the microphone holding portion detaching from the eartip portion due to friction during wearing, can be reduced.

[0049] Furthermore, the in-ear sound collection device according to the first embodiment has three or more legs. Figure 6 shows an example in which the number of legs is two. If there were only two legs, the legs would need to be thicker to prevent imbalances in the support force of the microphone holder, such as a difference between the left and right sides, making it difficult to increase the area of ​​the sound output opening relative to the internal space of the ear canal. By forming three or more legs as described above, it is possible to prevent imbalances in the support force of the microphone holder, and it is possible to make the legs thinner. Therefore, it is possible to increase the area of ​​the sound output opening relative to the internal space of the ear canal, allowing sound from the earphone to be efficiently propagated to the ear canal, thereby improving the measurement accuracy of the transfer function E_TF.

[0050] Furthermore, in the in-ear sound collection device of the first embodiment, a cable insertion opening (Mc) for inserting the microphone cable, which is the wiring cable from the microphone, is formed in the eartip portion at a position outside the earphone insertion portion. This prevents the microphone cable from being routed outside the eartip portion. Therefore, it is possible to prevent pain caused by the microphone cable being routed outside the eartip portion coming into contact with the ear canal wall when the device is worn. It is also possible to prevent the cable from being broken due to the microphone cable being routed outside the eartip portion coming into contact with the ear canal wall when the device is worn.

[0051] Furthermore, in the in-ear sound collection device of the first embodiment, the microphone cable is held by a tunnel portion (8) having an insertion hole portion (Hc) communicating with the cable insertion opening. This makes it possible to reduce the amount of sound leakage, which occurs when sound emitted from the earphone leaks out of the ear through the cable insertion opening. Therefore, sound from the earphone can be efficiently transmitted to the ear canal, improving the measurement accuracy of the transfer function E_TF.

[0052] Here, the use of the in-ear sound collection device 1 having the earphone insertion portion 6 is not limited to the use of measuring the transfer function E_TF for realizing sound field reproduction as exemplified in Fig. 1. For example, it can be widely used to measure the transfer function E_TF for various purposes, such as measuring the transfer function E_TF for creating an NC filter or for creating a sound quality correction filter.

[0053] 7 is a perspective view of the appearance of an in-ear sound collection device 10 according to a second embodiment. The in-ear sound collection device 10 according to the second embodiment is an in-ear sound collection device used to measure the transfer function S_HRTF described above. In the following description, parts that are the same as parts that have already been described will be assigned the same reference numerals and description thereof will be omitted.

[0054] In order to improve the accuracy of sound field reproduction as shown in Figure 1, it is ideal that the position of the sound collection surface 2a is the same in the measurements of the transfer functions S_HRTF and E_TF. For this reason, the in-ear sound collection device 1 used to measure the transfer function E_TF and the in-ear sound collection device 10 used to measure the transfer function S_HRTF should have the same basic shape and size.

[0055] 7, the in-ear sound collection device 10 is similar to the in-ear sound collection device 1 in that it has a microphone 2, a microphone holding part 4, and a plurality of legs 5. The differences from the in-ear sound collection device 1 are that it has an eartip part 3A instead of the eartip part 3, and that it has a connecting part 11.

[0056] The eartip portion 3A has an overall silhouette that is roughly bowl-shaped, similar to the eartip portion 3, but differs from the eartip portion 3 in that it has an outer wall portion 3Aa instead of the outer wall portion 3a, that it does not have an inner wall portion 3b, thus eliminating the earphone insertion portion 6 and tunnel portion 8, and that it does not have the inner circumferential cylinder portion 7. In this example, the entire inside of the outer wall portion 3Aa is an empty space.

[0057] The outer wall 3Aa has through holes Hs formed therein for transmitting sound from outside the ear into the ear canal when the earplug-type sound collection device 10 is worn. In the outer wall 3Aa of this example, a plurality of through holes Hs are formed as holes penetrating the side surface of the outer wall 3Aa, and specifically, three through holes Hs are arranged at equal intervals in the circumferential direction.

[0058] In the outer wall 3Aa, the portions between the through holes Hs are formed as inter-hole walls 3Ab. In this example, the opening area of ​​each through hole Hs is larger than the area of ​​the inter-hole walls 3Ab. By increasing the opening area of ​​the through holes Hs, more sound from outside the ear canal can be propagated into the ear canal, and the sound propagation characteristics of the speaker sound when measuring the transfer function S_HRTF can be made closer to the characteristics when the in-ear sound collection device 10 is not being worn.

[0059] The eartip portion 3A also has connecting portions 11 that connect each leg portion 5 and each inter-hole wall portion 3Ab. In this example, the number of leg portions 5 and the number of inter-hole wall portions 3Ab are the same; specifically, three of each are formed, and each inter-hole wall portion 3Ab is connected to a corresponding leg portion 5. In this case, the connecting portions 11 are formed as portions that connect each pair of thus connected leg portions 5 and inter-hole wall portions 3Ab in a ring shape. By providing such connecting portions 11, it is possible to increase the support strength of the microphone holding portion 4. In particular, it is possible to make it difficult for the microphone holding portion 4 to be pushed back in the direction opposite to the insertion direction into the ear canal when the in-ear sound pickup device 10 is worn.

[0060] As described above, the connecting portion 11 of this example connects each leg portion 5 and each inter-hole wall portion 3Ab in a ring shape, and therefore a gap portion is formed on the inner circumferential side of the connecting portion 11. This gap portion communicates with the gap portion inside the outer wall portion 3Aa, and also communicates with the sound emitting opening Ms formed between the leg portions 5. As a result, when the earplug-type sound collection device 10 is inserted, sound from outside the ear is propagated into the ear canal via the through-hole Hs formed in the outer wall portion 3Aa and the sound emitting opening Ms, improving sound propagation efficiency.

[0061] In the in-ear sound collection device 10, the microphone holding portion 4 also holds the microphone 2 so that the sound collection surface 2a faces the eardrum, and the microphone cable 2b is drawn out from the side opposite the sound collection surface 2a. In the in-ear sound collection device 10, the microphone cable 2b passes through a gap on the inner periphery of the leg portion 5 and a gap on the inner periphery of the connecting portion 11, as shown in the figure, and is routed to the outside of the eartip portion 3A through a gap on the inner periphery of the eartip portion 3A.

[0062] Furthermore, in the in-ear sound collection device 10 of this embodiment, the tip width (diameter of the tip in this example) of the eartip portion 3A is made wider than the maximum width (maximum diameter in this example) of the microphone holding portion 4. In other words, the maximum width of the microphone holding portion 4 is made narrower than the tip width of the eartip portion 3A.

[0063] In the in-ear type sound collection device 10 configured as described above, in this example, the ear tip portion 3A (including the connecting portion 11), the microphone holding portion 4, and the multiple legs 5 are integrally formed from an elastic material such as silicone or resin.

[0064] In the in-ear sound collection device 10 of this example, the silhouette shape and size of the eartip portion 3A, the shape and size of the microphone holding portion 4, and the shape and size of the leg portion 5 are approximately the same as those of the eartip portion 3, microphone holding portion 4, and leg portion 5 of the in-ear sound collection device 1, respectively, so that the positions of the sound collection surfaces 2a when worn are the same. However, in order to match the positions of the sound collection surfaces 2a when worn, it is not necessary to match the basic shapes and sizes of the in-ear sound collection devices 1 and 10, and it is also possible to match the positions of the sound collection surfaces 2a by other methods. For example, even if the number and size of the legs 5 are not the same, it is possible to match the positions of the sound collection surfaces 2a as long as the lengths (lengths from the outer side to the tip side) of the legs 5 are at least the same.

[0065] [3-2. Summary of the Second Embodiment] As with the first embodiment, the in-ear sound collector (10) of the second embodiment described above also includes an eartip portion (3A) that is held against the ear canal wall, and a microphone holder that is positioned closer to the eardrum than the eartip portion and holds a microphone. The microphone is held in the microphone holder so that the sound collection surface faces the eardrum. As with the first embodiment, this prevents the microphone cable from appearing inside the ear canal when the in-ear sound collector is worn, and also prevents the microphone cable from rubbing against the ear canal wall when worn. Therefore, the in-ear sound collector can improve the accuracy of measuring the transfer characteristics while preventing pain when worn.

[0066] In addition, in the second embodiment of the in-ear sound collection device, the maximum width of the microphone holding portion is narrower than the width of the tip of the eartip portion, making it easier to insert the eartip portion into the ear canal. This improves the fit of the in-ear sound collection device.

[0067] Furthermore, since the in-ear sound collection device of the second embodiment also uses the same microphone support part as in the first embodiment, the tip of the microphone holding part is tapered, which alleviates pain when the tip of the microphone holding part comes into contact with the wall of the ear canal when wearing the in-ear sound collection device. Therefore, the wearing comfort of the in-ear sound collection device can be improved.

[0068] The second embodiment of the in-ear sound collection device has a through-hole (Hs) formed in the outer wall of the eartip portion. This allows sound from outside the ear to propagate through the through-hole into the ear canal, realizing an in-ear sound collection device for measuring the transfer function S_HRTF (an in-ear sound collection device for measuring the transfer characteristics between the speaker and the ear canal).

[0069] Furthermore, in the in-ear sound collection device of the second embodiment, multiple legs are formed to connect the microphone holding portion to the eartip portion. This allows the in-ear sound collection device for transfer function S_HRTF measurement to have the same structure as the in-ear sound collection device for transfer function E_TF measurement, in correspondence with the case where the in-ear sound collection device for transfer function E_TF measurement is configured with multiple legs, like the in-ear sound collection device of the first embodiment, and it becomes possible to align the position of the microphone sound collection surface in the ear canal when worn. Therefore, it is possible to improve the accuracy of reproducing a three-dimensional acoustic space.

[0070] Furthermore, in the second embodiment of the in-ear sound collection device, the outer wall of the eartip portion has a plurality of through-holes arranged in the circumferential direction, and the spaces between the plurality of through-holes are formed as inter-hole walls (see 3Ab). The eartip portion has connecting portions (see 11) connecting each leg portion to each inter-hole wall. By providing connecting portions connecting the plurality of legs to the plurality of inter-hole walls as described above, the support strength of the microphone holding portion can be increased. Therefore, when the in-ear sound collection device is worn, the microphone holding portion is less likely to be pushed back in the direction opposite to the insertion direction into the ear canal. This prevents the transfer function S_HRTF from being measured at a sound collection surface position different from that used when measuring the transfer function E_TF, ensuring that the transfer function S_HRTF is measured appropriately.

[0071] 8 and 9, an example of the reproduction ear insert 20 will be described. When reproducing a sound field as shown in Fig. 1, the reproduction ear insert 20 is used to have a subject listen to a reproduced sound of an acoustic signal that has been subjected to a convolution operation by the above-mentioned filter F. Alternatively, when realizing the above-mentioned NC or various sound quality corrections, the reproduction ear insert 20 is used to have a subject listen to a reproduced sound of an acoustic signal that has been subjected to acoustic signal processing for the NC or various sound quality corrections.

[0072] Fig. 8 is an external perspective view of the playback ear insert 20, and Fig. 9 is a cross-sectional view of the playback ear insert 20. In order to suppress the discrepancy between the sound transfer characteristics during playback and the sound transfer characteristics when measuring the transfer function E_TF, it is ideal for the playback ear insert 20 to have the same basic shape and size as the in-ear sound collection device 1. For this reason, the playback ear insert 20 is configured so that the external shape and the size of each part are the same as those of the in-ear sound collection device 1.

[0073] Specifically, the playback earpiece 20 has an eartip portion 3B, an accessory portion 4B, multiple legs 5, and an inner cylindrical portion 7. The eartip portion 3B is configured as a member having approximately the same outer shape and size as the eartip portion 3. It differs from the eartip portion 3 in that it has an outer wall portion 3Ba instead of the outer wall portion 3a, and in that the tunnel portion 8 is omitted. The outer wall portion 3Ba differs from the outer wall portion 3a in that the cable insertion opening Mc is omitted. Like the eartip portion 3, the eartip portion 3B has an earphone insertion portion 6 formed inside the inner wall portion 3b.

[0074] The accessory portion 4B is a substitute for the microphone holding portion 4 in the in-ear sound collection device 1, and is configured so that its external shape and size are approximately the same as those of the microphone holding portion 4. Because the reproduction ear insert 20 does not require a microphone 2 for measuring the transfer function E_TF, the hole Hp corresponding to the microphone insertion hole Hm is filled with an elastic body 21 such as silicone or resin. While an example has been given in which the hole Hp corresponding to the microphone insertion hole Hm is formed in the accessory portion 4B, this makes it possible to reuse the microphone holding portion 4 of the in-ear sound collection device 1 in the manufacture of the reproduction ear insert 20. However, it is not necessary to mold the accessory portion 4B with the hole Hp and then fill the hole Hp later; a method of molding the accessory portion 4B without the hole Hp can also be used. The material filling the hole Hp is not limited to an elastic material, and a non-elastic material such as metal can also be used.

[0075] The accessory portion 4B has a main body portion 4Ba and a tip portion 4Bb, and as shown in the figure, the tip portion 4Bb is formed in a tapered shape similar to the tip portion 4b of the eartip portion 3.

[0076] In the reproduction ear insert 20, each leg 5 connects the ear tip portion 3B and the attachment portion 4B, and its shape and size are substantially the same as those of the leg portions 5 in the in-ear sound pickup device 1.

[0077] The inner cylindrical portion 7, like the inner cylindrical portion 7 in the ear-insertion type sound collection device 1, is formed as a portion in which the inner wall portion 3b extends toward the tip, is located on the inner side of each leg portion 5, and its size and shape are approximately the same as those of the inner cylindrical portion 7 in the ear-insertion type sound collection device 1.

[0078] In the playback earpiece 20 configured as described above, as in the in-ear sound collection device 1, sound emitted from the earphone 50 inserted in the earphone insertion portion 6 is propagated into the ear canal via the earphone hole He, the earphone opening Me formed in the inner cylindrical portion 7, and the sound emission opening Ms formed between the legs 5.

[0079] In this example, the playback earpiece 20, like the in-ear sound collection device 1, has an eartip portion 3B, an accessory portion 4B, multiple legs 5, and an inner tube portion 7 that are integrally formed from an elastic material such as silicone or resin.

[0080] In addition, the method for matching the sound transfer characteristics of the playback earpiece 20 with those of the earpiece 20 when measuring the transfer function E_TF is not limited to matching the basic shape and size (and material) of the earpiece 20 with those of the earpiece 1.

[0081] 5. Modifications Note that the embodiment is not limited to the specific examples described above, and various modified configurations can be adopted. For example, the above examples have been given of the in-ear sound collection devices 1 and 10 configured so that the sound collection surface 2a faces directly toward the eardrum, but the sound collection surface 2a may face the eardrum. For example, Figure 10 illustrates a configuration in which the microphone holding portion 4 is tilted obliquely with respect to the tip surface of the eartip portion 3 or 3A, so that the sound collection surface 2a faces in a direction obliquely shifted from a direction facing directly toward the eardrum. Note that Figure 10 schematically illustrates the legs 5, and the shape and number of the legs 5 are not limited to those shown.

[0082] Furthermore, although the above example shows the microphone holding portion 4 being made of an elastic material, the material of the microphone holding portion 4 is not particularly limited as long as it can at least hold the microphone 2. For example, as shown in Fig. 11, a coil-shaped microphone holding portion 4C made of a metal wire may be used instead of the microphone holding portion 4. Here, in the present technology, the microphone holding portion is not limited to being integrally molded with the eartip portion, and it is also possible to configure the microphone holding portion to be formed separately from the eartip portion and attached to the eartip portion.

[0083] Furthermore, with regard to the in-ear type sound collectors 1 and 10, it is conceivable to form a mesh portion 30, as shown in FIG. 12, on the sound collecting surface 2a in order to prevent foreign matter such as earwax from entering.

[0084] Furthermore, with regard to the in-ear sound collection devices 1, 10 (and the playback ear insert 20), it is also possible to form mesh portions 30 on various holes and openings involved in sound propagation into the ear canal. Fig. 13 shows an example in which a mesh portion 30 is formed on the sound emitting opening Ms between the legs 5, and Fig. 14 shows an example in which a mesh portion 30 is formed on the through-hole Hs portion of the in-ear sound collection device 10. Furthermore, Fig. 15 shows an example in which a mesh portion 30 is formed on the sound propagation path from the earphone insertion portion 6 to the sound emitting opening Ms in the in-ear sound collection device 1.

[0085] Furthermore, in the above example, the microphone cable 2b is routed through the cable insertion opening Mc formed on the distal end surface of the eartip portion 3 in the in-ear sound collection device 1, but the microphone cable 2b may be routed so that the cable does not intervene between the outer surface of the eartip portion 3 or microphone holding portion 4 and the wall of the ear canal when the in-ear sound collection device 1 is worn. For example, Fig. 16 shows an example in which the microphone cable 2b is routed through an insertion hole Hc formed so as to penetrate laterally through the inner wall portion 3b. Furthermore, Fig. 17 shows an example in which the microphone cable 2b is routed directly to the earphone 50 inside the earphone insertion portion 6 when the in-ear sound collection device 1 and the earphone 50 are integrally configured.

[0086] Furthermore, with regard to the ear insert type sound collecting devices 1, 10 (and the ear insert for reproduction 20), it is also conceivable to use, as the leg 5, a leg 5D having a reciprocating structure as shown in FIG. 18 as an example, which is given flexibility.

[0087] The effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0088] <6. The Present Technology> The present technology can also adopt the following configurations. (1) An in-ear sound collection device comprising: an eartip portion held on the wall of the ear canal; and a microphone holding portion positioned closer to the eardrum than the eartip portion and holding a microphone, wherein the microphone is held in the microphone holding portion so that the sound collection surface faces the eardrum. (2) The in-ear sound collection device according to (1), in which the maximum width of the microphone holding portion is narrower than the width of the tip of the eartip portion. (3) The in-ear sound collection device according to (1) or (2), in which the tip of the microphone holding portion is formed in a tapered shape. (4) The in-ear sound collection device according to any of (1) to (3), in which an earphone insertion portion into which an earphone is inserted is formed on the inner periphery of the eartip portion. (4) The in-ear sound collection device according to (4), in which a sound emission opening communicating with the earphone insertion portion is formed between the microphone holding portion and the eartip portion. (5) The in-ear sound collection device according to (5), in which a plurality of legs are formed to connect the microphone holding portion to the eartip portion. (7) The in-ear sound collection device according to (6), in which three or more legs are formed. (8) The in-ear sound collection device according to any of (4) to (7), in which a cable insertion opening for inserting a microphone cable, which is a wiring cable from the microphone, is formed in a position in the eartip portion that is outer than the earphone insertion portion. (9) The in-ear sound collection device according to (8), in which the microphone cable is held by a tunnel portion having an insertion hole portion communicating with the cable insertion opening. (10) The in-ear sound collection device according to any of (1) to (3), in which a through-hole is formed in an outer wall portion of the eartip portion. (11) The in-ear sound collection device according to (10), in which a plurality of legs are formed to connect the microphone holding portion to the eartip portion. (12) The ear-insertion type sound pickup device according to (11), wherein a plurality of through holes are arranged in the circumferential direction on the outer wall of the eartip portion, and the spaces between the plurality of through holes are formed as inter-hole wall portions, and the eartip portion has connecting portions that connect each of the leg portions to each of the inter-hole wall portions.

[0089] DESCRIPTION OF SYMBOLS 1, 10: Earplug-type sound collecting device 2: Microphone 2a: Sound collecting surface 2b: Microphone cable 3, 3A: Eartip portion 3a, 3Aa: Outer wall portion 3b: Inner wall portion 4, 4C: Microphone holding portion 4a: Main body portion 4b: Tip portion 5: Leg portion 6: Earphone insertion portion 6a: Locking portion 7: Inner cylindrical portion 8: Tunnel portion Hm: Microphone insertion hole Mc: Cable insertion opening He: Earphone hole portion Me: Earphone opening Ms: Sound emission opening Hs: Through hole 3Ab: Wall portion between holes 11: Connection portion 20: Earplug for playback 30: Mesh portion

Claims

1. An in-ear sound pickup device comprising: an eartip portion that is held on the wall of the ear canal; and a microphone holder that is positioned closer to the eardrum than the eartip portion and holds a microphone, wherein the microphone is held in the microphone holder so that the sound pickup surface faces the eardrum.

2. The in-ear type sound pickup device according to claim 1, wherein the maximum width of the microphone holding portion is narrower than the width of the tip of the eartip portion.

3. The in-ear type sound pickup device according to claim 1, wherein the tip of the microphone holding part is formed in a tapered shape.

4. The in-ear type sound pickup device according to claim 1, wherein an earphone insertion section into which an earphone is inserted is formed on the inner periphery of the ear tip section.

5. The in-ear type sound pickup device according to claim 4, further comprising a sound emission opening communicating with the earphone insertion section between the microphone holding section and the ear tip section.

6. The in-ear type sound pickup device according to claim 5, wherein a plurality of legs are formed to connect the microphone holding portion to the ear tip portion.

7. The in-ear type sound pickup device according to claim 6, wherein three or more legs are formed.

8. The in-ear sound pickup device according to claim 4, wherein a cable insertion opening for inserting a microphone cable, which is a wiring cable from the microphone, is formed in the ear tip portion at a position outside the earphone insertion portion.

9. The in-ear type sound pickup device according to claim 8, wherein the microphone cable is held by a tunnel having an insertion hole communicating with the cable insertion opening.

10. The in-ear type sound pickup device according to claim 1, wherein a through hole is formed in the outer wall of the ear tip portion.

11. The in-ear type sound pickup device according to claim 10, wherein a plurality of legs are formed to connect the microphone holding portion to the ear tip portion.

12. An in-ear sound pickup device as described in claim 11, wherein a plurality of through holes are arranged in the circumferential direction on the outer wall of the eartip portion, and the spaces between the plurality of through holes are formed as inter-hole walls, and the eartip portion has connecting parts that connect each of the leg parts to each of the inter-hole walls.

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