JP4124236B2 - Brass silencer - Google Patents

Description

  The present invention relates to a sealed silencer for the purpose of attenuating the sound of brass instruments such as trumpet and trombone.

  As a silencer for attenuating the sound generated by playing brass instruments, a structure shown in FIG. 7 is known. A sealing member 109 made of cork, rubber, sponge or the like is wound around the entire periphery of the base end of the silencer 101 shown in the figure, and when this silencer 101 is attached to the bell 105 of the trumpet 103, for example. Since the fitting portion 107 of the sealing member 109 is in close contact with the inner peripheral surface of the bell 105, the internal space 111 of the silencer 101 is sealed.

  If the inner space 111 is completely sealed by mounting the silencer 101 in this way, the exhalation of the blower blown from the mouthpiece 113 loses its outlet and cannot be discharged, making it difficult to play. . In view of this, a discharge port 115 is provided at a tip portion where the bottom surface 117 of the silencer 101 is folded back and protruded into the internal space 111 so as to release the exhalation of the blower (for example, Patent Document 1).

  As described above, the silencer whose inside is substantially sealed is called a sealed silencer. If the opening diameter of the discharge port 115 is reduced, the sound of the sound leaking into the external space is reduced and the noise reduction effect is obtained. It is done. By the way, when a conventional sealed silencer including the structure of the silencer 101 described above is mounted on a brass instrument bell, the sound pressure distribution is reflected on the bottom surface of the sealed silencer because the sound wave at the time of blowing is reflected. It is different from the sound pressure distribution when no sealed silencer is installed.

  4 (A) to 4 (D), the upper part of each figure shows a standing wave that is effective for generating second, fourth, sixth, and eighth harmonics when played without a sealed silencer. This shows the state of the sound pressure distribution, and the tube part from the mouthpiece 113 to the bell 105 is expanded straight to facilitate understanding. In the figure, the portion of the standing wave 119 that hits the peak 121 has a high sound pressure, while the portion of the standing wave 119 that hits the valley 123 shows a low sound pressure.

  As can be seen from the figure, the terminal end 125 of the standing wave 119 is converged by reducing the sound pressure at the substantially end face 127 of the bell 105. Since the position of the terminal end 125 of the standing wave 119 is determined by the shape of the bell 105 or the like, the position is not necessarily on the end surface 127 of the bell 105, but it does not deviate greatly from this position. The position of the terminal end 125 can be on the substantially end surface 127 of the bell 105.

  However, when the conventional silencer 101 is mounted as shown in FIGS. 8A to 8D, the silencer 101 protrudes forward (direction B shown in FIG. 8) from the end face 127 of the bell 105. Therefore, an extra standing wave 129 having a quarter wavelength is generated. This extra standing wave of ¼ wavelength increases the sound pressure toward the bottom surface 117 of the silencer 101 protruding forward from the end surface 127 of the bell 105. The formation of the extra standing wave 129 having a quarter wavelength is a characteristic when a conventional hermetic silencer is mounted.

  In this manner, when an extra standing wave 129 having a quarter wavelength is present, the terminal 125 of the standing wave 119 effective for pitch generation is rearward from the end face 127 of the bell 105 (C ), The pitch rose extremely, and the pitch balance was lost. Especially in the low range, almost a semitone was also raised.

To rationally design a sealed silencer to avoid such problems, only a length (H) corresponding to a quarter wavelength of a typical standing wave that is a harmonic overtone that provides the original tone of the instrument can be obtained. In addition, an exhalation outlet 115 is provided at a position extending forward (B side) from the end face 127 of the bell 105, or the middle part of the cylinder part of the main body has a maximum inner diameter, and is formed in a shape that tapers toward both ends. Thus, it is possible to improve the pitch and pitch balance without being affected by the presence of an extra standing wave 129 having a quarter wavelength.
Japanese Patent No. 2865030

  In such a conventional sealed silencer, as described above, the end face of the bell 105 has a length (H) corresponding to a quarter wavelength of a typical standing wave of a brass instrument to which the exhalation outlet 115 is attached. It must be provided at a position extending from 127 to the front (B side). For this reason, the bottom surface 117 of the silencer 101 has a shape that protrudes forward (B side) from the end surface 127 of the bell 105, and the weight increases. Therefore, when such a sealed silencer is mounted on a brass instrument, there is a problem in that the weight of the tip increases and the balance is biased forward, affecting the blowing posture.

  In recent years, for example, it has been demanded that a brass instrument equipped with a silencer can be played in accordance with the accompaniment of an external sound source and recorded as an practice form of wind music. In this case, the electronic circuit module and the power supply components for converting the blowing sound collected by the microphone incorporated in the silencer into an electric signal are separately configured as a single unit. However, this unit and the silencer must be connected with multiple cables, including the possibility of accidents where this cable gets intertwined or gives the blower a shocking sound due to the drop of the connected cable. Met.

  The present invention has been made to solve the above-described conventional problems, and provides a sealed brass silencer capable of obtaining a good silencing effect while reducing the degree of protrusion from the end of the brass instrument bell. The pitch, pitch and feeling of wind are improved. Further, by configuring as described above, the electronic module and the power supply components can be built into the silencer body so as to be compact, and a separate sound unit can be output as an electric signal without using a separate unit. The purpose is to do so.

Therefore, the present invention solves the above problems by means described below. That is, according to the first aspect of the present invention, the silencer is mounted on a brass instrument bell. The bottom of the silencer main body has the maximum diameter and the inner peripheral surface of the brass instrument bell to be mounted. A cylindrical body portion that is smoothly reduced in diameter along the axial direction of the outer periphery of the tubular body portion, and when mounted on a brass instrument bell, the silencer is attached to the end surface of the bell. While positioning the bottom of the main body, and letting the exhalation in the silencer body from the end on the small diameter side of the silencer body through the exhalation discharge path to the external space, and when attached to the bell of the brass instrument, The maximum diameter portion of the bottom of the silencer body is located on the end face of the bell, and the upper end of the body of the silencer body is a quarter wavelength of a typical standing wave of the brass instrument from the end face of the bell. Brass music that is only located behind the bell Made to be use silencer.

According to a second aspect of the present invention, in the silencer for a brass instrument according to the first aspect, a housing portion including a power source and an electronic circuit module is provided at the bottom of the silencer body, and provided inside the inclined portion of the trunk portion. The bottom surface of the adjustment cylinder is made a diameter, a microphone is disposed at a position that advances from the point on the axis of the bottom surface toward the bottom of the silencer by the radius , and the microphone and the electronic circuit module are connected by a signal line. .

  According to the first aspect of the present invention, the overall length of the silencer main body can be reduced to approximately half that of the conventional sealed silencer, so that it is lightweight and compact, and the pitch balance can be maintained correctly. In addition, it is possible to obtain a stable sound with no sounding unevenness in the entire sound range.

  According to the second aspect of the present invention, since it is possible to configure a light weight, a power source and an electronic circuit module can be disposed in the main body, and unitization for converting the sound of a sound into an electric signal is easy. Can be realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, with a trumpet as a representative example.

  1 to 4 show a first embodiment of the present invention, and show a state in which the silencer 1 according to the present invention is attached to the bell 105 of the trumpet 103. This silencer 1 is shown in FIG. And as shown in FIG. 3, the main body is comprised by the trunk | drum 3 and the bottom part 5. As shown in FIG. The trunk portion 3 includes a straight portion 9 and an inclined portion 11, and the straight portion 9 is parallel to the axial direction (BC direction) of the silencer body 7 and is a large diameter side end that is an upper end portion of the trunk portion 3. The straight portion 9 side including the portion 13 forms the maximum outer diameter portion and the maximum inner diameter portion 15 of the silencer body 7.

  Since the inclined portion 11 is continuous with the straight portion 9 and has a tapered shape that is smoothly inclined and narrowed from the position end portion of the straight portion 9 along the inner peripheral surface of the bell 105, the end portion on the small diameter side Reference numeral 17 denotes a minimum outer diameter portion and a minimum inner diameter portion 19 of the silencer body 7. Therefore, the inner space 21 of the main body 1 increases in diameter as it advances in the B direction along the axial direction (BC direction). With this shape, the silencer 1 is attached to the bell 105. There is no unevenness in the sound, and a sound with good pitch can be obtained. As a result, a stable feeling of wind can be obtained.

  When the silencer 1 is mounted on the bell 105, the outer peripheral surface of the inclined portion 11 is fitted with the inner peripheral surface of the bell 105 at the fitting portion 23. In this case, when the body portion 3 is formed of a flexible synthetic resin, the material is elastically fixed to the inner peripheral surface of the bell 105 due to the properties of the material, but the fitting portion 23 is flexible like a cork. You may make it stick a member with property.

  Next, on the outer peripheral surface of the inclined portion 11 of the trunk portion 3, an exhalation discharge path 25 is formed for discharging exhalation of the blower to the external space. This exhalation discharge path 25 extends in the axial direction (B-C direction) so as to follow the shape of the inner peripheral surface of the bell 105, and one end reaches the small diameter side end portion 17 of the inclined portion 11. On the other hand, the other end of the exhalation discharge path 25 is set to be positioned forward (B side) from the end portion of the fitting portion 23 when the silencer 1 is attached to the bell 105. Therefore, when the silencer 1 is mounted on the bell 105, the communication space 27 defined by the recess of the exhalation discharge path 25 and the inner peripheral surface of the bell 105 is the rear (C side) of the fitting portion 23, that is, the mouthpiece. 113 communicates with the internal space 21 of the silencer 1 and communicates with the external space in front of the fitting portion 23 (B side).

  The cross-sectional area F of the surface perpendicular to the axial direction (BC direction) of the silencer body 7 of the communication space 27 is equal to or larger than the cross-sectional area of the minimum diameter portion (throat) of the inner diameter of the mouthpiece of the trumpet 103. As a result, it is possible to prevent an additional increase in the direct-current flow resistance of exhaled air that adversely affects the feeling of blowing. Since the throat inner diameter of the trumpet 103 is about φ3.7 mm, the cross-sectional area F is set equal to or larger than this.

  A flange 31 is formed at the boundary between the straight portion 9 and the inclined portion 11 for fixing the bottom portion 5 bent toward the large-diameter side end portion 13 in the middle. An adjustment tube 33 extending so as to coincide with the axial direction (BC direction) is provided inside the inclined portion 11, and one end of the adjustment tube 33 is connected to the small diameter side end portion 17 of the inclined portion 11. Match. On the other hand, a flange 35 extending outward is formed on the other end of the adjustment cylinder 33, and the outer peripheral edge of the flange 35 is coupled to the inner peripheral surface of the inclined portion 11. That is, the outer circumferential surface of the adjustment cylinder 33, the C direction side surface of the flange portion 35, and the inner circumferential surface of the inclined portion 11 define an annular space in which the small diameter side end portion 17 side of the inclined portion 11 is opened.

  The dimensions of the adjustment cylinder 33 need to be set differently depending on the type of the corresponding instrument. However, when the trumpet 103 in the present embodiment is in a gradual adjustment, the adjustment cylinder 33 has an inner diameter of φ15 mm, an outer diameter of φ17 mm, and a long length. The length is about 15 mm. By providing the adjusting cylinder 33, the pitch of the trumpet 103 can be slightly lowered, and in particular, the pitch balance in the low range can be improved.

  Next, the bottom portion 5 is formed in a bowl shape having a plate thickness of 2.0 mm or more with a synthetic resin (for example, ABS resin) and is fitted to the outer peripheral surface of the large-diameter side end portion 13 of the body portion 3. The open end is press-fitted into an insertion portion formed by the outer peripheral surface of the flange 31 and the straight portion 9 of the body portion 3. The joint portion 35 between the bottom portion 5 and the straight portion 9 of the body portion 3 is sealed so that air in the internal space 21 of the silencer body 7 does not leak from this portion. You can get no stable sound.

  When the silencer 1 configured as described above is attached to the bell 105, the maximum inner diameter portion 15 of the bottom portion 5 is positioned on the end surface 127 of the bell 105. Further, the length G in the axial direction (BC direction) from the end face 127 of the bell 105 to the small diameter side end portion 17 of the inclined portion 11 is ¼ wavelength of a typical standing wave (sixth harmonic) of the trumpet 103. Is set to substantially match the length corresponding to.

  Comparing the dimensions of the silencer 1 of the present invention designed under such conditions with the conventional silencer 101, the overall length in the axial direction (BC direction) of the conventional silencer 101 is L. On the other hand, the total length in the axial direction (BC direction) of the silencer 1 of the present invention is approximately ½. Further, when the conventional silencer 101 is mounted on the bell 105 of the trumpet 103, the distance protruding forward (B side) from the end surface 127 of the bell 105 is H (see FIG. 7), whereas the silencer of the present invention When the device 1 is mounted, the distance protruding from the end face 127 of the bell 105 is approximately H / 7. Therefore, compared with the conventional silencer 101, the silencer 1 of the present invention can be made compact.

  FIG. 4 is a diagram comparing the sound pressure distributions when the trumpet 103 is not equipped with the silencer 1 of the present invention and when the trumpet 103 is worn and in the same manner as in FIG. 4 (A) to 4 (D) shows the state of the sound pressure distribution of the standing wave when the silencer 1 is not attached to the upper stage of each of the diagrams, and FIG. FIG. 4B shows the state of the sound pressure distribution of the standing wave of the fourth harmonic, FIG. 4C shows the sixth harmonic, and FIG. 4D shows the eighth harmonic.

  As is clear from the figures, the standing wave 119 is converged by lowering the sound pressure toward the end face 127 of the bell 105 even when the silencer 1 is attached, as in the case where the silencer 1 is not attached. Is located on the substantially end face 127 of the bell 105. In addition, even when the silencer 1 is mounted, an extra standing wave 129 having a quarter wavelength is generated, and this standing wave is the rear (C side) silencer 1 from the end face 127 of the bell 105. The sound pressure increases toward the small-diameter end 17 of the inclined portion 11. That is, in the silencer 1 of the present invention, an extraordinarily generated ¼ wavelength standing wave is generated in the opposite direction to that of the conventional silencer 101, and thus, from the end face 127 of the bell 105. It is possible to drastically reduce the length of the silencer 1 protruding.

  Therefore, the exhalation of the blower blown from the mouthpiece 113 toward the bottom portion 5 of the silencer body 7 is discharged from the internal space 21 of the silencer body 7 through the communication space 27 to the external space. A standing wave corresponding to each overtone is generated. In the silencer 1 of the present invention, the length G from the end face 127 of the bell 105 to the small diameter side end 17 is set so as to match the quarter wavelength of the standing wave of the sixth harmonic. , The terminal end 125 of the standing wave 119 effective for generating the pitches of the second harmonic, the fourth harmonic, the sixth harmonic, and the eighth harmonic including the sixth harmonic coincide with the substantially end surface 127 of the bell 105, respectively. As a result, the movement of the end 125 of the sound pressure of each standing wave 119 is small, and it is possible to play with good pitch and pitch.

  Next, a silencer 37 according to a second embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part of the structure similar to the silencer 1 which concerns on 1st Embodiment, and the description is abbreviate | omitted.

  In the second embodiment of the present invention, an annular cover 39 is provided on the outer periphery of the bottom portion 5, and this annular cover 39 communicates with the exhalation discharge path 25 and the inner peripheral surface of the bell 53. The space 41 on the small diameter side end portion 17 side of the bell 53 communicating with the space 27 is substantially separated from the external space. The annular cover 39 is integrally formed of a synthetic resin with a spring member 47 that contacts the inner peripheral surface of the bell 53 while urging the peripheral portion 45 of the cover 43 that contacts the inner peripheral surface of the bell 53. It becomes.

  Even in the above configuration, since the blowing is difficult unless the breath of the blower is discharged to the external space, the cover portion 43 of the annular cover 39 is formed with a breathing hole 49 that allows the space 41 to communicate with the external space in a limited manner. Yes. The breathing hole 49 has the same concept as the exhalation discharge path 25, that is, the inner diameter of the breathing hole 49 is set to be equal to or larger than the cross-sectional area of the smallest diameter portion (throat) of the inner diameter of the mouthpiece of the trumpet 103. ing. The breathing hole 49 prevents not only the exhalation of the blower but also the moisture contained in the exhalation from accumulating in the space 41 and also functions to maintain cleanliness.

  Further, a protrusion 51 corresponding to the end surface of the spring portion 47 is formed on the outer peripheral surface of the bottom portion 5 of the silencer 37 over the entire periphery. Therefore, the inner peripheral surface of the annular cover 39 is fitted to the outer peripheral surface of the bottom portion 5 so as to be slidable in the axial direction (B-C direction), and the end portion of the spring member 47 abuts on the protrusion 51. Never go off.

  With this configuration, when the silencer 37 is attached to the bell 53 having a relatively gentle curve on the inner surface of the opening, the elastic function of the spring portion 47 of the annular cover 39 as shown in FIG. As a result, the peripheral edge portion 45 of the cover portion 43 of the annular cover 39 strongly contacts the inner peripheral surface of the bell 53 over the entire circumference except the portion of the breathing hole 49. On the other hand, when the silencer 37 is attached to the bell 55 having a relatively steep curve on the inner surface of the opening, the elastic action of the spring member 47 of the annular cover 39 is reduced as shown in FIG. The peripheral portion 45 of the cover portion 43 of the annular cover 39 weakly contacts the inner peripheral surface of the bell 53 over the entire circumference except the portion of the breathing hole 49.

  As apparent from the above, since the spring member 47 is disposed in a compressed state between the protrusion 51 of the bottom portion 5 and the flange 31 of the trunk portion 3, the annular cover 39 can be mounted even if the shape of the bell to be mounted is different. The contact state between the inner peripheral surface and the peripheral portion 45 of the cover portion 43 can be maintained. As a result, the space 41 surrounded by the inner peripheral surface of the bells 53 and 55, the outer peripheral surface of the silencer 1 and the surface in the C direction of the annular cover 39 becomes a chamber structure (silence chamber), and thus leaked from the communication space 27. The ringing sound is further attenuated.

  Next, a silencer 57 according to a third embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the part of the structure similar to the silencer 37 which concerns on 2nd Embodiment, and the description is abbreviate | omitted.

  The silencer 57 according to the third embodiment of the present invention incorporates a power source (dry battery) 59 and an electronic circuit module 61. Unlike the silencer 37 of the second embodiment, the projection 64 for holding the annular cover 39 provided on the outer peripheral surface of the bottom 63 of the silencer 57 further extends forward (B side). A bent portion is provided on the inner peripheral surface side. An electronic circuit board 65 is provided in front of the bottom portion 5 (B side), and the electronic circuit board 65 is fitted into a bent portion and fixed.

  Further, a lid 67 for covering the component mounting surface is fitted in front of the electronic circuit board 65 so as to be freely opened and closed at the tip end portion of the protrusion 63. Therefore, the electronic circuit board 65 and the lid 67 define the power supply 59 and the accommodation chamber for the electronic circuit module 61. A through hole 71 through which the signal line 69 is passed is formed at the center of the bottom 5, and a conical protrusion 73 that rises from the periphery of the through hole 71 and extends in a tapered state in the C direction is provided. The signal line 69 extends in the axial direction (BC direction) toward the mouthpiece 113 through the inside of the through hole 71 and the protrusion 73. A fitting portion between the signal line 69 and the protrusion 73 is covered with a waterproof heat-shrinkable pipe 75.

  One end of the signal line 69 is connected to the power source 59 and the electronic circuit module 61, and the other end is connected to the microphone 77. Further, the microphone 77 and the signal line 69 in the vicinity thereof are covered with a waterproof heat shrinkable pipe 79 and a packing 81. Therefore, the waterproof heat-shrinkable pipes 75 and 79 and the packing 81 can prevent moisture accumulated in the internal space 21 of the silencer 57 from entering the electronic circuit module 61 and the microphone 77.

  The microphone 77 and the signal line 69 in the vicinity thereof are fixed to a fixing portion protruding from the inner peripheral surface of the inclined portion 11 of the silencer 57 via a waterproof heat-shrinkable pipe 79 and a packing 81 covering the microphone 77 and the silencer 57. Fixed. The microphone 77 has a bottom surface 83 of the adjusting cylinder 33 with a diameter M, and is provided at the bottom 5 of the silencer 57 from the point on the axis of the bottom surface 83 by the radius (M / 2), that is, at a position advanced in the B direction. It is done. Since this position is a position where the sound pressure balance of effective standing waves of each overtone is good, it is possible to collect well-balanced sounds over the entire sound range.

  As described above, since the silencer 57 itself is provided with the power supply 59 and the electronic circuit module 61, it is possible to accommodate functions related to recording and reproduction as separate units, so that the wind sound can be heard directly with an earphone or the like. In addition, the reverberation effect is given to the listening sound by the switch function, and the music signal from the compact disc etc. can be taken in by providing the input / output jack, for example, wind practice while listening to the accompaniment sound is possible. It is also possible to output the signal obtained from the wind sound to the outside for recording.

  Comparing the dimensions of the silencer 57 thus configured with the conventional silencer 101, the overall length in the axial direction (BC direction) of the conventional silencer 101 is L, whereas the silencer The total length of 57 in the axial direction is 2 / 3L. When the conventional silencer 101 is attached to the bell 105 of the trumpet 103, the distance protruding forward (B side) from the end surface 127 of the bell 105 is H, whereas when the silencer 57 is attached, The distance protruding from the end face 127 of 105 is approximately H / 3. Thus, even when the power source 59 and the electronic circuit module 61 are incorporated in the silencer 57, it is possible to achieve a more compact size than the conventional silencer 101.

  As described above in detail, in the present invention, the exhalation discharge path 25 communicating with the internal space 21 of the main body 1 is provided in the axial direction of the outer periphery of the trunk section 3, and this exhalation discharge path 25 transmits the exhalation of the blower to the external space. Therefore, the discharge port 115 of the conventional silencer 101 is not necessary, and the overall length of the silencer main body can be shortened. In addition, it is possible to play with a good pitch and pitch without being affected by an extraordinarily generated ¼ wavelength standing wave.

  In the description of the present embodiment, the exhalation discharge path 25 is described based on an example formed at one place, but it may be provided at a plurality of places. In this case, the minimum diameter portion (throat) of the inner diameter of the mouthpiece of the corresponding brass instrument is the sum of the cross-sectional areas of the communication space 27 defined by the concave portion of the exhalation discharge path 25 and the inner peripheral surface of the inclined portion 11 of the silencer 1. What is necessary is just to set it more than this cross-sectional area. Further, when the breathing holes 49 described in the second embodiment are formed at a plurality of locations, the degree of opening may be set based on the same setting as described above.

  The silencer of the present invention is not limited to a synthetic resin, and can be formed of other materials such as metal, and is not limited to a specific material. The brass instrument to which the silencer of the present invention is attached is not limited to the trumpet, and can be widely applied to other brass instruments.

It is a perspective view of the silencer concerning a 1st embodiment of the present invention. It is a partial cross section figure of the silencer of FIG. It is the sectional view on the AA line of FIG. It is a figure explaining the state of the sound pressure distribution of the standing wave by the silencer of FIG. It is sectional drawing of the silencer which concerns on the 2nd Embodiment of this invention. It is sectional drawing of the silencer which concerns on the 3rd Embodiment of this invention. It is sectional drawing of the conventional silencer. It is a figure explaining the state of the sound pressure distribution of the standing wave by the silencer of FIG.

Explanation of symbols

1 .... Muffler 3 .... Body 5 .... Bottom 7 .... Muffler body 9 .... Linear part 11 ....・ Inclined part 15 ... Maximum inner diameter part 17 ... Small diameter side end part 19 ... Minimum inner diameter part 25 ... Exhalation discharge path 27 ... Communication space 33 ... ············································································ 39 ································································································· Trumpet 105 ... Bell 119 ... Standing wave 125 ... End of standing wave 127 ... End face of bell

Claims (2)

It is a sealed silencer attached to the bell of a brass instrument,
Consists of a cylindrical body that is smoothly reduced in diameter along the shape of the inner peripheral surface of the bell of the brass instrument to be mounted and the bottom that is the maximum diameter of the silencer body,
Forming an exhalation discharge path in the axial direction of the outer periphery of the cylindrical trunk,
When mounted on the bell of a brass instrument, the bottom portion of the silencer body is positioned on the end surface of the bell, and the exhaled air in the silencer body from the small-diameter end of the silencer body passes through the exhalation discharge path to the external space. To let it drain,
Further, when mounted on the bell of a brass instrument, the maximum inner diameter portion of the bottom portion of the silencer body is located on the end surface of the bell, and the upper end portion of the body portion of the silencer body extends from the end surface of the bell. A silencer for a brass instrument, wherein the silencer is located at a position backward of the bell by a quarter wavelength of a typical standing wave. While providing a storage chamber with a power source and an electronic circuit module at the bottom of the silencer body, the bottom surface of the adjustment cylinder provided inside the inclined portion of the trunk is a diameter, and the radius is from the point on the axis of the bottom surface. 2. A silencer for a brass instrument according to claim 1, wherein a microphone is disposed at a position proceeding toward the bottom of the silencer , and the microphone and the electronic circuit module are connected by a signal line.

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