JP4530423B2 - A three-dimensional sound microphone and a three-dimensional sound reproduction device. - Google Patents

Description

The present invention indeed relates stand body sounds microphone and stereo sound reproducing apparatus to generate a three-dimensional sound signal realism overflowed similar sounds as for listening by ear.

  Conventionally, stereo microphones have been used to collect and record bird calls or thunders, or to record musical performances. That is, incoming sounds such as bird calls or thunder are collected by a microphone, amplified and listened to by headphones.

  However, since headphones are played near the entrance to the ear canal, this playback method detects the auditory system at the location of the headphones. As a result, there has been a problem that it is impossible to obtain a stereo effect full of realism for listening to sounds other than the left and right directions, up and down, front and back.

  Therefore, it is possible to make the listener enjoy the reverberation sound in the recording system with a three-dimensional spread while the sounding body is localized in a natural tone, and to reduce the intensity of the reverberation sound by the binaural signal. No. 217400.

  As shown in FIG. 15, the sound signals recorded by the recording means 3 and 4 directly recorded from the sounding body 2 of the sound collection system 1 and the recording means 6 and 7 arranged at the ears of the dummy head 5 are recorded. The acoustic signals that have been mixed are gained by gain control circuits 10, 11, 12, and 13 at the mixing stage. At this time, delay elements 8 and 9 may be provided.

  The signals delayed by the delay elements 8 and 9 are processed by the crosstalk processing unit 14 and then added to the amplifiers 15 and 16 together with the acoustic signals from the gain control circuits 10 and 11 to sound the headphones 18 of the listener 17. In this way, reverberation direction information can be recorded by binaural recording of only reverberation sound.

  Japanese Patent Laid-Open No. 11-127500 discloses a binaural stereo sound technique for reproducing a sound field with a sense of reality by reproducing sound recorded by a dummy head microphone with headphones and listening with both ears. .

As shown in FIGS. 16 and 17, a binaural sound collecting / reproducing apparatus for reproducing sound collected by using a dummy head microphone 20 by means of headphones 21, wherein the left and right speaker portions 22 of the headphones 21 are the left and right ears of the headphones. When the sound is output from the speaker unit 22, the sound image localization filtering unit 25 uses the sound image localization filtering unit 25 to convert the acoustic characteristics of the space 24 from the speaker unit 22 to the auricle mounting unit. The sound signal output from the sound signal is convolved, thereby correcting the amplitude and phase lag, improving the sense of sound localization in the forward direction of the listener, and giving the listener a good sense of localization of the out-of-head sound image. Are listed.
JP-A-6-217400 JP-A-11-127500

  In the conventional three-dimensional sound reproducing device described in Japanese Patent Laid-Open No. 6-217400, the appearance such as the shape of the head is taken into account, but the influence from the ear canal to the eardrum and the function of the brain due to this are ignored, so In addition, sounds that are different from those in the natural world or listening to music performances are reproduced, and a special dummy head and a circuit for controlling gain or a complicated circuit such as a crosstalk addition circuit are required. become.

  Since the conventional three-dimensional sound reproducing device described in Japanese Patent Laid-Open No. 11-127500 also ignores the influence from the ear canal to the eardrum and the function of the brain, etc., actually listen to nature or music performance through the auricle. Sounds different from the above are reproduced, and a special headphone is required, so that the versatility is poor, and a sound image localization filtering unit for generating a signal having a reverse characteristic of the acoustic characteristic is required, which is expensive.

The present invention provides a practically for standing body sounds Ru generates a sound signal overflow same realism and for listening by ear microphone and stereo sound reproducing apparatus the sound from the sound source.

In the present invention, a sound signal with a sense of presence that is similar to the reality when a sound from a sound source is actually heard with a simple configuration is generated, a microphone element that converts the sound into a sound signal, and an incoming sound from the sound source A bottomed reflector that generates a delayed sound that is delayed by a time corresponding to the time required to return to the outer ear by reflecting the incoming sound from the outer ear through the outer ear canal and reflected by the eardrum. When it is more, to form a synthesized speech obtained by superimposing the delay sound and invaded sound arriving from the slit, adding the synthesized sound to the microphone element, to provide a standing body sounds for microphone Ru generate synthesized speech signal .

Furthermore, the present invention uses a bidirectional microphone element as the microphone element, a reflector is provided on the outer periphery of the bidirectional microphone element, the reflecting cylinder is provided on the rear surface of the bidirectional microphone element, and both the reflecting cylinders are provided. Three-dimensional sound that adds incoming sound from the sound source to the surface of the directional microphone and adds the incoming sound that has entered through the slit to the back of the bidirectional microphone element and the delayed sound reflected by the reflecting cylinder to generate a synthesized sound signal A microphone is provided.

In the present invention, there is a microphone element that converts sound into a sound signal and a slit into which the incoming sound from the sound source enters, and the incoming sound that has entered from the slit is reflected from the outer ear through the ear canal and reflected by the eardrum to the outer ear. A three-dimensional solid tube that includes a bottomed reflecting tube that generates a delayed sound that is delayed by a time corresponding to a return time, and adds an incoming sound that has entered through the slit and the delayed sound to a microphone element to generate a synthesized sound signal. There is provided a three-dimensional sound reproducing device serving as a sound microphone and a headphone for reproducing sound from a synthesized sound signal converted by the microphone.

  The sound reproduction method of the present invention is a delay in which a true arrival sound that directly enters from the sound source and a time corresponding to the time when the arrival sound is reflected from the outer ear through the ear canal and reflected by the eardrum and returned to the outer ear by the delay sound generation means. Since the sound signal is synthesized with the synthesized sound means and the synthesized sound signal is generated, and the sound is reproduced from the synthesized sound signal with the sound reproducing means, it is possible to hear a sound full of realism that exists in the natural world. it can.

  The three-dimensional sound microphone of the present invention includes a true incoming sound that directly enters the outer ear from the sound source, a delayed sound that is delayed by a time corresponding to the time when the incoming sound is reflected from the outer ear through the ear canal and is returned to the outer ear, and returns to the outer ear. Since the synthesized sound on which is superimposed is added to the microphone element, when a sound signal obtained from the microphone element is listened to by the headphones, a sound full of presence similar to that existing in the natural world can be heard.

  The three-dimensional sound reproduction apparatus of the present invention combines a sound directly coming from a sound source with a microphone and a delayed sound that is delayed by a time corresponding to the time when the sound is reflected by the eardrum from the outer ear through the ear canal and returns to the outer ear. Since the sound is picked up and converted into a synthesized sound signal, it can be heard in the same way as the sound from the sound source is directly heard by the ear. Therefore, when applied to a hearing aid, it is possible to realize an out-of-head sound image localization that shows not only the left and right but also the front and back and top and bottom.

  The three-dimensional sound reproduction apparatus of the present invention superimposes a sound directly coming from a sound source with a microphone and a delayed sound that is delayed by a time corresponding to the time when the sound is reflected from the eardrum through the ear canal and returned to the outer ear. The synthesized sound is picked up and converted into a synthesized sound signal, the converted synthesized sound signal is recorded on a recording / reproducing means such as a tape or MD, and the synthesized sound signal recorded by the recording / reproducing means is reproduced. You can hear the sound of a bird's voice or thunder, or a sound full of realism similar to a musical performance.

  In the above-mentioned case, the sound that directly arrives from the sound source with the microphone and the synthesized sound in which the sound is reflected from the outer ear through the ear canal and reflected by the eardrum and is delayed by the time corresponding to the time to return to the outer ear are collected and synthesized. Although the sound signal was converted into a sound signal, the sound signal recorded by a normal microphone was delayed by a time equivalent to the time required for the sound to be reflected from the eardrum through the ear canal through the sound signal delay circuit and returned to the outer ear by the sound signal delay circuit. The sound signal is generated, the delayed sound signal delayed by the sound signal delay circuit and the sound signal converted by the microphone are synthesized by the sound signal synthesis circuit to generate a synthesized sound signal, and the synthesized sound signal from the sound signal synthesis circuit is generated. In addition to headphones, sound is played back, so when applied to hearing aids, it is possible to realize an out-of-head sound localization that can be understood not only from the left and right but also from front to back and from top to bottom.

  Similar to the above, the sound synthesis signal of the sound signal recorded with a normal microphone and the delayed sound signal delayed by the time equivalent to the time when the sound is reflected from the outer ear to the eardrum and returned to the outer ear by the sound signal delay circuit. Since it was recorded by the recording / reproducing device, it can be heard by the recording / reproducing device at any time with the sound of a realistic bird voice or thunder or a realistic sound similar to a musical performance.

  If the microphone bidirectional microphone element is used, a reflection cylinder serving as an external auditory canal can be provided on the rear surface of the microphone element, so that the frequency characteristics of the incoming sound coming from the front side are not affected.

  The present inventor determines the time corresponding to the arrival sound, which is a true sound that enters the sound collection means such as a microphone from the sound source, and the time when the arrival sound is reflected by the eardrum from the outer ear through the ear canal and returned to the outer ear by the delay sound generation means. By synthesizing the delayed delayed sound signal with the synthesized sound means, generating a synthesized sound signal, and reproducing the sound from the synthesized sound signal with the sound reproducing means, a sound full of realism similar to that in the natural world is heard. It was confirmed by experiment that it was possible.

  FIG. 1 is a block diagram showing a sound reproduction system of the present invention that realizes listening to the above-mentioned sound full of realism.

  The sound collecting means 34 that collects the true incoming sound that directly enters from the sound source 40 and converts it into an incoming sound signal, and delays the time corresponding to the time when the incoming sound is reflected from the eardrum through the ear canal and returned to the outer ear. A delayed sound generating means 35 for generating a delayed sound signal, a synthesized sound signal generating means 36 for generating a synthesized sound signal from the incoming sound signal and the delayed sound signal, an amplifier 37 connected to the synthesized sound signal generating means 36, It consists of headphones 33. As the sound collecting means 34, a microphone is usually used.

  FIG. 2 shows a cross-sectional view of a model of the human ear canal. The human ear canal 30 has a diameter of about 7 mm, the length from the ear canal entrance 31 to the eardrum 32 where the ear canal 30 is placed is 23 to 27 mm, and the ear canal has a volume of about 1 milliliter.

  As shown in FIG. 3, when the incoming sound A reaches the vicinity of the ear canal entrance 31 of the ear canal 30, the incoming sound A and the reflected sound B reflected by the eardrum 32 of the preceding sound preceding the ear canal 30 are at the interference point C. You will rub each other. As a result, a new wavefront D is generated at the interference point C when the reflected sound B is in phase with the incoming sound A and becomes a trough when in the opposite phase.

  If the present inventor detects the new wavefront D, amplifies it, and reproduces the new wavefront D with headphones placed in the vicinity of the interference point C, the presence of the headphones is not noticed by the auditory system due to the action of brain cells. I thought that I could perceive the incoming sound A and its position.

  Therefore, as shown in FIG. 4, the headphone 39 was placed at the interference point C, and a new wavefront D was added to the headphone 39 for the experiment. As a result, the actual wavefront D newly generated is also reproduced in the headphones 39 placed at the interference point C, so that the presence is reduced, and the listener of the headphones 39 can hear the reproduced sound of the incoming sound A. The sound source direction at the time of recording is perceived with respect to the reproduced sound, and the characteristic is suitable for a three-dimensional sound.

  This is realized by the sound reproduction system shown in FIG. 1, and the true incoming sound A from the sound source 40 is collected by the sound collecting means 34. The sound collected by the sound collecting means 34 is generated by a delayed sound generating means 35 and a synthesized sound signal generating means 36 to generate a synthesized sound signal. The synthesized sound signal is amplified by the amplifier 37, and the headphones 33 are driven to reproduce the sound. The reproduced sound includes a sound in which the incoming sound is reflected by the eardrum from the outer ear through the ear canal and delayed for a time corresponding to the time of returning to the outer ear, so that the headphones 33 placed at the interference point C are also newly added. If the actual wavefront D generated in the above is reproduced, the same effect can be obtained. Therefore, as described above, the presence of the headphones is weakened, and the listener of the headphones 33 can hear the reproduction sound of the incoming sound A, and the sound source direction at the time of recording is perceived by this reproduction sound and the sound with a sense of presence is overflowing. I can listen.

  There are two methods for the delayed sound generating means 35 and the synthesized sound signal generating means 36 for obtaining the delayed sound signal and the synthesized sound signal described above.

  The first method is an acoustic method in which the incoming sound collected by the sound collecting means 34 is reflected by the eardrum from the outer ear through the ear canal and delayed for a time corresponding to the time it returns to the outer ear. Let Then, the collected incoming sound and the delayed delayed sound are added to the sound collecting means 34 to generate a synthesized sound signal.

  The second method is an electrical method in which the incoming sound from the sound source 40 is collected by the sound collecting means 34, the collected sound is converted into a sound signal, and then the incoming sound is received from the outer ear. A delay sound signal is obtained by delaying the time corresponding to the time of reflection from the eardrum through the ear canal and returning to the outer ear with a delay element. Then, the sound signal converted by the sound collecting means 34 and the delayed sound signal are synthesized by the synthesized sound signal generating means 36 to generate a synthesized sound signal.

  FIG. 5 is a first method for acoustically obtaining the delayed sound signal and the synthesized sound signal described above, and shows a cross-sectional view of the microphone 41 that detects a new wavefront D using a dummy external auditory canal.

  FIG. 6 shows a front view of a microphone 41 that detects a new wavefront D using the dummy external auditory canal of FIG. The microphone 41 includes a microphone element 42, a reflecting cylinder 43 and a reflecting plate 44. The microphone element 42 may be a normal electret microphone (ECM), and the microphone element 42 has a flat frequency characteristic between 20 Hz and 20000 Hz. The reflector 44 is made of rubber and reflects sound from the sound source and shields sound from the rear.

  The reflection cylinder 43 has a slit 46 and a bottom 48 for collecting sound from the sound source 40. The sound that is reflected from the sound source 40 directly or reflected by the reflector 44 through the slit 46 is directly added to the microphone element 42 and is also reflected by the bottom of the reflecting tube 43 and the reflected sound is also added to the microphone element 42.

  Therefore, the synthesized sound in which the incoming sound that directly enters the microphone element 42 from the slit 46 of the reflecting cylinder 43 and the reflected sound reflected by the bottom 48 are superimposed on the microphone element 42 is added and converted from the output terminal 47 into an electric signal. Sound signal is output.

  The length of the reflecting cylinder 43 is such that the incoming sound that enters through the slit 46 is reflected by the bottom 48 and added to the microphone element 42, and the incoming sound is added to the outer ear, and the sound applied to the outer ear is added to the eardrum. The length is such that it is time to reflect and return to the outer ear again.

  In other words, the length of the reflecting cylinder 43 is the distance from the outer ear to the eardrum. As described above, the distance from the outer ear to the eardrum varies depending on each person, and varies between adults and children. However, since the average from 23 mm to 27 mm is 25 mm, the length of the reflecting cylinder 43 is 25 mm and the interval between the slits 46 is about 2 mm. The sound that enters through the slit 46 of the reflecting cylinder 43 is reflected by the bottom 48 of the reflecting cylinder 43, and the time for the reflected sound to reach the microphone element 42 is about 150 microseconds.

  FIG. 7 shows a cross section of a microphone 49 that detects a new wavefront D at the interference point C using a dummy external ear canal that implements the first method for acoustically obtaining a delayed sound signal and a synthesized sound signal in the same manner as described above. In the figure, the point that the bidirectional microphone element 50 is used is different from the microphone of FIG. It comprises an omnidirectional microphone element 50 and a reflecting cylinder 51 provided on the back side.

  The reflection tube 51 has a slit and a bottom for collecting sound from the sound source 40. The sound that enters from the sound source 40 through the slit is directly applied to the bidirectional microphone element 50 and is reflected by the bottom of the reflecting tube 51, and the reflected sound is also added to the bidirectional microphone element 50.

  As shown in FIG. 8, in the omnidirectional microphone element 50, the incoming sound E from the front side passes through the microphone element 50 and generates a + output passing sound on the back side. On the other hand, the incoming sound G from the back side generates -output passing sound -H on the front side. In this way, the incoming sound E from the front surface side becomes + output, but the reflected sound from the back surface side reflected by the reflecting tube 51 becomes -output. That is, an output voltage proportional to the particle velocity of the sound wave appears at the output terminals OUT1 and OUT2.

  As shown in FIG. 9, a composite wavefront D is generated at the interference point C. At this time, a voltage proportional to the particle velocity of the sound wave flowing into and out of the ear canal from the interference point C is detected by using a bidirectional microphone element 50 such as a velocity microphone at the interference point C. After amplification, the interference point C is detected with the earphone. Similar results were obtained even when played near. In this case, the length of the reflecting cylinder 51 is set to 25 mm, which is the same as the length of the standard ear canal, so that the delay time is 150 microseconds.

  Therefore, as shown in FIG. 7, the bidirectional microphone element 50 is used, the reflection tube 51 is provided on the rear surface of the microphone element 50, and the incoming sound that has entered from the slit is added to the surface of the bidirectional microphone element 50, By adding the delayed sound reflected by the reflecting cylinder 51 to the back surface of the omnidirectional microphone element 50, a synthesized sound signal can be generated.

  FIG. 10 is a block diagram of the three-dimensional sound reproducing apparatus of the present invention using the microphone 41 shown in FIG. 5. However, the same applies to the microphone 49 shown in FIG. To do.

  The three-dimensional sound reproducing apparatus of the present invention includes a right and left microphone 41, an amplifier 52 for amplifying a sound signal from an output terminal 47 of the microphone 41, a recording / reproducing device 53 for recording / reproducing the sound signal amplified by the amplifier 52, and a recording / reproducing. It comprises an amplifier 54 and a headphone 60 that amplify the sound signal reproduced by the machine 53.

  As shown in FIG. 11, the microphones 41 and 41 are arranged so that their tips are directed outward at an appropriate angle in order to record left and right sounds. An amplifier 52 is connected to the microphones 41 and 41, and a recording / reproducing device 53 such as a tape recorder, a DVD player, or an MD player is connected to the amplifier 52. An amplifier 54 and headphones 60 are connected to the recording / reproducing machine 53.

  For example, to record a bird's voice in a musical performance or outdoors using the three-dimensional sound reproducing apparatus of the present invention, the microphones 41 and 41 are directed toward the sound source 40. The incoming sound from the sound source 40 is reflected directly or by the reflector 44 and enters the reflectors 43 and 43 through the slits 46 and 46 of the reflectors 43 and 43 of the microphones 41 and 41. The incoming incoming sound is directly applied to the microphone elements 42 and 42 and reflected by the bottoms 48 and 48 of the reflecting cylinders 43 and 43, and the reflected reflected sound is superimposed on the incoming incoming sound from the slits 46 and 46 to produce a synthesized sound. And the synthesized sound is added to the microphone elements 42, 42.

  The microphone elements 42 and 42 convert the synthesized sound signal, which is an electrical signal corresponding to the synthesized sound, and output the output from the output terminals 47 and 47. The synthesized sound signal is amplified by an amplifier 52 and recorded by a recording / reproducing device 53.

  When it is desired to listen to the sound recorded by the recording / reproducing device 53, the synthesized sound signal recorded from the recording / reproducing device 53 is taken out by setting the recording / reproducing device 53 to the reproduction state. The extracted synthesized sound signal is amplified by the amplifier 54 and applied to the headphone 60, and the reproduced sound is delayed by a time corresponding to the time when the incoming sound is reflected from the eardrum through the ear canal and returned to the outer ear. Since sound is included, sound with a sense of reality that is similar to listening to actual sound through the auricle is reproduced.

  In the above, the case where the music performance or the voice of the bird was recorded outdoors and the recorded music performance or the voice of the bird was reproduced later was explained. However, in the hearing aid, it is necessary to immediately reproduce the sound recorded by the microphones 41 and 41.

  As shown in FIG. 12, headphones 60 are directly connected to an amplifier 54 when used in a hearing aid. Then, as in the case described above, the microphone 41 is directed toward the sound source 40. The incoming sound from the sound source 40 is reflected directly or by the reflection plate 44 and enters the reflection cylinder 43 through the slit 46 of the reflection cylinder 43 of the microphone 41. The incoming incoming sound is directly applied to the microphone element 42 and reflected by the bottom 48 of the reflecting cylinder 43, and the reflected reflected sound is superimposed on the incoming incoming sound from the slit 46 to form a synthesized sound, and the synthesized sound is the microphone. Added to element 42.

  It is converted into a synthesized sound signal which is an electric signal corresponding to the synthesized sound by the micron element 42 and outputted from the output terminal 47. The synthesized sound signal is amplified by the amplifier 54, applied to the headphones 60, and the headphones 60 are driven to reproduce the sound. Therefore, the user can hear as a hearing aid a sound having an out-of-head sound image localization feeling that is directly heard by the ear.

  FIG. 13 is a block diagram showing an embodiment of the three-dimensional sound reproducing apparatus of the present invention realized by the second method for electrically generating a delayed sound signal and a synthesized sound signal. In the above description, the special microphone 41 is used. However, a stereoscopic sound reproducing apparatus with a sense of realism can be realized even when a generally used stereo microphone is used. An amplifier 62 is connected to the microphone 61, and a sound signal delay circuit 63 is connected to a part of the output of the amplifier 62. The sound signal delay circuit 63 is connected to the sound signal synthesis circuit 64 together with the amplifier 62. The sound signal synthesis circuit 64 is connected to a recording / reproducing machine 65 and an amplifier 66.

  The sound signal delay circuit 63 delays a part of the sound signal amplified by the amplifier 62, and the delay time is a time corresponding to the time when the sound is reflected from the eardrum through the ear canal and returned to the outer ear. . The delayed sound signal delayed by the sound signal delay circuit 63 and the sound signal amplified by the amplifier 62 are added to the sound signal synthesis circuit 64 to generate a synthesized sound signal.

  In the block diagram of FIG. 13, the microphone 61 is directed toward the sound source 40 in order to record a musical performance or a bird's voice outdoors. The incoming sound from the sound source 40 is added to the microphone 61. The incoming sound applied to the microphone 61 is converted into a sound signal. The sound signal is amplified by the amplifier 62. The sound signal amplified by the amplifier 62 and the delayed sound signal delayed by the sound signal delay circuit 63 are added to the sound signal synthesis circuit 64 to generate a synthesized sound signal. The synthesized sound signal is recorded in the recording / reproducing device 65.

  When it is desired to listen to the sound signal recorded by the recording / reproducing device 65, the recording / reproducing device 65 is set in a reproduction state. Then, the headphone 67 is driven after being amplified by the amplifier 66 recorded from the recording / reproducing device 65. The sound reproduced by the headphones 67 includes a sound in which the incoming sound is reflected from the outer ear through the ear canal and reflected by the eardrum and is delayed for a time corresponding to the time of returning to the outer ear. Play sounds with a sense of realism.

  As shown in FIG. 14, when used for a hearing aid, a sound signal delay circuit 63 is connected to the amplifier 62 instead of the recording / reproducing device 65. Therefore, the collected sound is converted into a sound signal by the microphone 61. The sound signal is amplified by the amplifier 62. A part of the amplified sound signal is generated by the sound signal delay circuit 63 so that the sound is reflected from the outer ear through the ear canal, reflected by the eardrum, and delayed for a time corresponding to the time for returning to the outer ear. The delayed sound signal is superimposed on the sound signal from the amplifier 62 by the sound signal synthesis circuit 64 to form a synthesized sound signal. The synthesized sound signal is applied to the headphone 67 through the amplifier 66, and a sound having an out-of-head sound image localization feeling similar to that heard directly by the ear can be reproduced.

It is a block diagram of the sound reproduction system of this invention. It is a model cross section of an external auditory canal for demonstrating the principle of the microphone for three-dimensional sound of this invention. It is a cross-sectional model diagram which shows the operation | movement of an external auditory canal for demonstrating the principle of the three-dimensional sound microphone of this invention. It is model sectional drawing in order to demonstrate the principle of the microphone for three-dimensional sound of this invention. It is a model sectional view of the microphone for three-dimensional sound of the present invention. It is a model top view of the microphone for three-dimensional sound of this invention. It is model sectional drawing which shows the other Example of the microphone for three-dimensional sound of this invention. It is an operation | movement figure explaining the action | operation of the three-dimensional sound microphone of this invention of FIG. FIG. 9 is a principle diagram for explaining the principle of the three-dimensional microphone of the present invention shown in FIG. It is a block diagram of the three-dimensional sound reproduction apparatus of this invention. It is a perspective view of the microphone for three-dimensional sound of the present invention. It is a block diagram of the other three-dimensional sound reproduction apparatus of this invention. It is a block diagram of a three-dimensional sound reproducing device showing another embodiment of the present invention. It is a block diagram of the three-dimensional sound reproduction apparatus which shows the other Example of this invention. It is a block diagram of the conventional three-dimensional sound reproduction apparatus. It is a block diagram of a three-dimensional sound reproducing device showing another conventional example. It is a model figure of the headphone part used for the conventional three-dimensional sound reproduction apparatus of FIG.

37 Amplifier 40 Sound source 41 Microphone 42 Microphone element 43 Reflector tube 44 Reflector plate 46 Slit 47 Output terminal 48 Bottom 52 Amplifier 53 Recording / playback machine

Claims (4)

A microphone element that converts sound into a sound signal;
There is a slit through which the incoming sound from the sound source enters, and the incoming sound from the slit is reflected from the outer ear through the ear canal and reflected by the eardrum, and a delayed sound is generated by delaying the time corresponding to the time to return to the outer ear. It consists of a bottomed reflector,
A three-dimensional sound microphone characterized in that an incoming sound that has entered through the slit and the delayed sound are added to a microphone element to generate a synthesized sound signal. A bidirectional microphone element is used as the microphone element, a reflector is provided on the outer periphery of the bidirectional microphone element, the reflecting cylinder is provided on the rear surface of the bidirectional microphone element, and the reflecting cylinder of the bidirectional microphone is provided. An incoming sound from a sound source is added to the front surface, and a synthetic sound signal is generated by adding the incoming sound that has entered from the slit to the back surface of the bidirectional microphone element and the delayed sound reflected by the reflecting cylinder. Item 3. A microphone for three-dimensional sound according to Item 1 .   The three-dimensional sound microphone according to claim 1, wherein the diameter of the reflecting tube is about 7 mm, the length is 23 to 27 mm, and the volume is about 1 milliliter. It has a microphone element that converts sound into a sound signal and a slit through which incoming sound from the sound source enters. Corresponding to the time when the incoming sound from the slit is reflected by the eardrum from the outer ear through the ear canal and returns to the outer ear A stereophonic microphone that generates a synthesized sound signal by adding a arriving sound and a delayed sound that have entered through the slit to a microphone element, ,
A three-dimensional sound reproducing apparatus, which is a headphone for reproducing sound from a synthesized sound signal converted by the microphone.

Images