FR3047382A1 - METHOD AND DEVICE FOR TAKING SOUND IN A WIND INSTRUMENT - Google Patents

Abstract

The invention relates to a method and a device (10) for sound recording in a wind instrument (1). The device (10) comprises a transducer sensitive to the vibrations of the air column produced in the resonator (3) of the instrument during its use, as well as a signal receiving device (12) emitted by the transducer. The transducer is placed in the instrument (1) in a sound zone (40) defined as being a portion of the bore of the instrument (1), deprived of the acoustic chamber (43), extending, following the axis of the bore, from the exciter (41) of the instrument (1) to a point on the axis of the bore at a distance (44) from the output of the equivalent instrument to the diameter (45) of this output. The invention also relates to an instrument (1) on which the device (10) according to the invention is mounted.

Description

The invention relates to the field of sound recording in a wind instrument and in particular in a wind instrument of the family of woods such as saxophones and clarinets.

[002] A wind instrument consists of a resonator provided at one of its ends with an exciter.

[003] For clarinets or saxophones, the exciter is a simple reed attached to a spout on a portion of its length including one end, the other end being free and able to oscillate under the action of the flow of air produced by a musician and alternately opening and closing the end of the beak. For oboes, and bassoons, the exciter is a "double reed", consisting of two reeds facing one another, fixed at one of their ends, and vibrating according to the same principle as the simple reed For wind instruments in the brass family, the exciter is the lips of the musician. For flutes, the exciter consists of the jet of air produced by the musician towards a bevel and oscillating and will be referred to in this document as the "aerial reed". In the case of the flute, the jet of air is controlled directly by the musician, while in the case of the recorder it is produced in a channel. The exciter of the flutes is said to be open and the pressure is imposed by the atmospheric pressure. The others are said to be closed.

[004] In this document will be called "acoustic chamber" the region of the air column in which there is a strong acoustic interaction between the exciter and walls of the instrument. This zone determines the spectral balance of the sound and contributes to the tone of the instrument, by favoring certain modes of vibration of the exciter compared to other modes.

[005] This acoustic chamber corresponds, in the case of saxophones and clarinets, to the portion of the bore located at the right of the vibrating part of the reed, which corresponds to the curved portion of the spout table.

[006] In the case of double-reed instruments, the acoustic chamber is the unligated part of the reeds.

[007] In the case of instruments of the family of brass, the acoustic chamber is the area of the mouth cup located in a cylinder defined by the straight extension of the bore taken at the mouth grain. Thus, the area near the edges of the mouth is not part of the acoustic chamber thus defined.

[008] In the case of instruments of the family of flutes, the acoustic chamber is the area of establishment of Γ "aerial reed".

[009] The resonator consists of a tube of variable section. In the case of woods, the resonator may include holes in the wall of the tube, and may also be provided with keys to open or close the holes, thus changing acoustic parameters such as the length of the air column. In the case of brass, this length can be modified by actuating valves in translation or in rotation which connect portions of bore of different lengths between them.

The inner shape, or the inner profile, of the tube is called "bore" ("boron" in English). This piercing can for example be close to a cylinder (clarinets, flutes), a cone (saxophones, oboe) or have a more complex shape, involving portions of cones, cylinders or Bessel curves revolution ( for the brass pavilion in particular).

The air column located in the bore is the seat of a standing wave when a note is emitted. The open holes, the horn, but also the exciter open in the case of flutes, allow the acoustic wave to radiate outside the bore. In the rest of the sequence, the "end of the bore" will be called the end of the bore provided with an exciter, and the "end of the bore" the other end. The "exit of the bore" is the exit of the flag when the instrument is equipped with it.

It is common for musicians to want to amplify, record, edit, correct, and so on. the sounds produced by their instruments.

Sound recording devices are known including a microphone mounted on a stand, hooked on the musician or attached to the body of the instrument. US 3,482,026 and EP 0 423 858 B1, for example, disclose a device comprising a microphone and fastening means for attaching a microphone to the horn of a wind instrument. However, this type of device has the following drawbacks in particular: [0014] reception of surrounding noise (also called acoustic crosstalk or "repisse"), conduction of the spurious noise generated by the impact of the keys of the instrument, 0016] - acoustic feedback effect (called "Larsen effect"), [0017] - lack of homogeneity of the sound over the range due to the variable number of transmitters scattered in the space (flag, open holes and open exciter on if applicable) according to the notes issued.

This results in a more or less deformed sound depending on the location of the microphone, sound problems in medium high volume (large scenes) and limited use, if not impossible, effects (electronic processing for echo, distortion, etc.) due to acoustic crosstalk and feedback.

Another solution has been proposed, known as "Varitone" (US3457357), of sensing the acoustic wave in the tube near the exciter. According to this solution, a sound pickup device comprising a microphone is positioned outside the tube and communicates with the bore through a diaphragm. The realization of this diaphragm has the disadvantage of requiring a modification (drilling, machining, brazing, etc.) of the instrument. Another disadvantage is that the hot and humid air blown by the musician condenses on the cold surfaces (the walls of the tube, the sound pickup device). This can cause problems when using this sound pickup device (forming drops impeding the passage of air or the movements of the microphone membrane) and accelerate its aging. This solution nevertheless makes it possible to improve the homogeneity of the sound reproduction according to the notes played (but the sound can also be altered by the diaphragm). The position of the microphone can isolate it from certain surrounding noises and greatly reduce acoustic crosstalk and feedback, but does not always avoid picking up key noises and other shocks transmitted by the instrument.

It has also been proposed in US2138500 to directly capture the vibrations of a reed, attaching thereto an armature whose movements generate changes in the flow in a connected electromagnetic coil, through a wall of the coil. instrument, to a signal processing device. This solution has many disadvantages, including: [0021] - a modification of the vibration properties of the reed, [0022] - a permanent modification of the instrument (at least to pass the son through the wall of the instrument) , [0023] a poor reproduction of the sound due to the source of the signal, that is to say the movements of the reed, which differ from the vibrations of the air column itself.

- A modification of the acoustic properties of the chamber of the mouthpiece of the instrument by the introduction of elements in this part of the instrument, etc.

An object of the invention is to at least partially overcome some of the disadvantages of the devices mentioned above.

This goal is at least partly achieved with a sound recording method in a wind acoustic instrument, this wind instrument comprising an exciter (single reed, double reed, lips, reed "aerial", etc.) and a resonator having an inner shape defining a bore. According to this method, a transducer sensitive to the vibrations of the air column produced by the exciter is provided and the transducer is placed in a sound pickup zone defined as being a portion of the instrument bore, deprived of the acoustic chamber, extending, along the axis of the bore, from the exciter of the instrument to a point on the axis of the bore at a distance from the output of the instrument equivalent to the diameter of this output. The sound pickup zone therefore corresponds to a portion of the instrument bore extending from the exciter, but outside the acoustic chamber, to a zone of the bore situated at a distance substantially equal to the diameter of the output This distance is measured from the exit, along the axis of the bore, towards the exciter. In other words, it excludes from this sound zone, the last portion of the bore to the output whose dimension along the axis of the bore is of the order of magnitude of the diameter of this output.

As indicated above, for brass, the acoustic chamber extends in the mouth along and around the axis of the bore on a radius corresponding essentially to that of the smallest section of the mouth. For these instruments, the sound zone (in which the transducer can be positioned) therefore comprises the region of the mouth located between the acoustic chamber and the wall of the mouth. Thus, except for these instruments, the sound pickup zone can generally be defined as being a portion of the bore of the instrument, extending, along the axis of the bore, the output of the acoustic chamber of the instrument to a point on the axis of the bore at a distance from the output of the instrument equivalent to the diameter of this output.

In the sound pickup area thus defined, the transducer is little, if any, sensitive to acoustic crosstalk, Larsen effect and other parasitic noises. It is indeed possible to limit or eliminate the acoustic crosstalk and Larsen effect by remaining in an area of the bore in which there is a strong preponderance of the standing wave compared to the surrounding noise.

It may be noted, for example, that the Larsen effect occurs on average at higher acoustic levels of 23dB in the case of a transducer placed at the entrance of the instrument's jar, compared with the case of microphones placed outside the chamber. pierces, of various directivities.

In this area, the transducer may be subjected to high acoustic pressures produced in the bore. It is therefore advantageously chosen for its behavior at such acoustic pressures. For example, under pressures of up to 171dB RMS relative to 20pPa ("Sound Pressure Level (SPL)", total harmonic distortion ("THD") must be less than or equal to 5 %. Some balanced frame transmitters ("balanced"), used in reverse, and therefore in receivers, can satisfy this type of constraint. This is the case, for example, of the Knowles Corporation manufacturer's transducer, reference RAB-22257. Directly used receiver transducers (microphones) are generally designed to operate at significantly lower acoustic pressures, typically 120-130dB for 5% THD, with a maximum of 154dB for specific applications.

In addition, the transducer is not in direct thermal contact with a cold source (outside air, internal or external wall of the instrument), its temperature is close to that of the hot air contained in the bore and the condensation is moderate with respect to the walls, which constitute surfaces on which the drops are preferentially formed.

In this sound zone, the transducer essentially captures the vibrations of the air column located in the bore. But contrary to the prejudices of the musicians, a transducer thus placed in the sound zone defined above does not necessarily modify the acoustic characteristics of the instrument. Indeed, the inventor has found that by placing the transducer out of the "acoustic chamber", we can not change the tone of the instrument.

In addition, the method according to the invention may comprise one or the other of the following characteristics considered independently of one another or in combination with one or more other (s): [0034] a signal emitted by the transducer, using a receiver device located outside the borehole; this makes it possible to limit the volume and the bulk of the element to be introduced into the sounding zone and thus to reduce the risks of acoustic disturbance degrading the musical qualities of the instrument; - The transducer is placed in the sound zone and the receiver, using at least one cable that is insinuated between two parts of the instrument; thus, the implementation of the method according to the invention requires no lasting modification of the instrument; [0036] the transducer and the receiver are removably attached to the instrument; more precisely, the transducer is removably attached to a part of the instrument, before fitting this part with another; - Analog or digital processing is optionally applied to the signal emitted by the transducer.

In another aspect, the invention relates to a device, in particular for the implementation of the previous method. It comprises a transducer, a device for receiving the signal emitted by the transducer and connection means between the transducer and the device receiving the signal emitted by the transducer. These connection means between the transducer and the receiver device, allow communication between the transducer and the receiver device, when the transducer is placed in a sound pickup zone defined as being a portion of the bore of the instrument, deprived of the acoustic chamber, extending, along the axis of the bore, from the exciter of the instrument to a point on the axis of the bore at a distance from the output of the instrument equivalent to diameter of this output.

This device may comprise one or the other of the following characteristics considered independently of one another or in combination with one or more other (s): [0040] the connection means may be with or without wire (according to the Bluetooth communication standard for example); The transducer is at least partially overmoulded in an elastomer cell; the elastomer acts as a damper for undesirable vibrations likely to propagate for example from the body of the instrument to the transducer; thus it is possible to preserve the transducer of the transmission of certain vibrations (key noises, shocks); the elastomer also protects the transducer mechanically and against any drops; the elastomer also protects the electrical connection between the transducer and a cable, moisture and risks of tearing welds; it also protects the instrument against any scratches made on the instrument by hard parts of the transducer; the elastomer also thermally isolates the transducer from cold sources (wall of the instrument), bringing its temperature closer to that of the hot air contained in the bore and limiting the formation of condensation on its surface; The cell comprises a vent putting in direct communication the transducer and the air of the sound zone; thus, even if the elastomer protects most of the transducer, the vibrations of the air column of the bore are transmitted, without deformation, to the transducer; It comprises holding means secured to the cell, for hanging the cell on the instrument, in the sound zone; these holding means help the musician to precisely place the cell in the sound zone; an appropriate positioning of the cell can also make it possible to limit or even prevent runoff of drops on the vent putting in direct communication the transducer and the air of the piercing; The signal receiving device emitted by the transducer comprises an intermediate housing connected by a wired connection to the transducer and a remote processing unit of the signal; this intermediate housing allows in particular to provide a separable connection (taken or transmission by radio waves) with the remote housing, which can be larger and heavier than the intermediate housing; thus, the instrument can remain lighter and more easily manipulated; [0045] it comprises a wired connection comprising a flat cable; this flat cable is adapted to be inserted at a joint between two parts of the instrument; for example, the flat cable is inserted between the spout and the seal of the jar, usually in cork, for a saxophone, between the seal of the spout and the barrel, for a clarinet, etc. ; thus, the flat cable may have a thickness less than or equal to 0.4 mm and / or a width less than or equal to 2.5 mm, and more advantageously still, less than or equal to 1.5 mm, so as not to hinder or degrade the operation of the seal (sealing, sliding of parts together); The transducer is of the electromagnetic type with balanced armatures; thus, it is possible to obtain a high efficiency which, correlatively, allows the transducer to be further miniaturized and introduced into the sound pickup zone without causing any acoustic disturbance degrading the musical qualities of the instrument; Moreover this type of transducer allows operation under high acoustic pressure produced in the bore; this while having a robustness specific to dynamic transducers.

In another aspect, the invention relates to a wind instrument comprising an exciter and a resonator having an inner shape defining a piercing. This instrument is equipped with a transducer sensitive to the vibrations of the air column. The transducer is placed in a sound pick-up zone defined as being a portion of the instrument bore, deprived of the acoustic chamber, extending, along the axis of the instrument bore, of the exciter to a point on the axis of the bore at a distance from the output of the instrument equivalent to the diameter of this output.

This instrument may comprise one or the other of the following characteristics considered independently of one another or in combination with one or more other (s): [0049] a receiving device of the signal emitted by the transducer is placed out of the bore, while the transducer is placed in the sound zone; - The transducer placed in the sound zone and the receiver are connected by means of a cable inserted at a joint between two parts of the instrument; - The transducer is at least partially overmolded in an elastomeric cell provided with holding means for hanging the cell on the instrument, in the sound zone; - The holding means are at least partly inserted at a joint between two parts of the instrument.

Moreover, one could fear that the introduction of an element in the sound zone disturbs the establishment of the standing wave in terms of frequency (accuracy of the instrument) and playability (ease to issue a note).

But the inventor has found that the disturbances associated with the introduction of an element into the bore are small, even negligible, if, at a given position in the sound picking zone defined above, the introduced element has a small section relative to the local section of the bore corresponding to this position, and if the length of the introduced element is less than the local diameter of the bore corresponding to this position. For example, a generally parallelepipedic element introduced into the sounding zone will cause a disturbance that is practically undetectable by the musician if he satisfies the following geometric criteria: (a) the section of this element is less than or equal to 11% of the local corresponding to the bore (that is, the section of the zone in which the element is placed); and (b) the length of this element is less than or equal to 80% of the corresponding local diameter of the bore.

For example, to meet these criteria throughout the "sound pickup area" instruments having a minimum diameter of 12.8mm bore, an element, such as a sound pickup cell having a transducer overmolded in a elastomer, may have a cross section of 3.5x4mm2 and a length of 10mm.

The saxophones having a tapered bore, the entry of the jar is the zone of the weakest section and it is there that the geometric criteria are the most restrictive.

The tenor saxophones, baritone and bass and all instruments of the clarinet family all have a bore whose minimum diameter is greater than or equal to 12.8 mm.

For alto, soprano and sopranino saxophones, all of which have a bore whose minimum diameter is less than 12.8 mm, a cell comprising the transducer having a cross section of 3.5 × 4 mm 2 and a length of 10 mm is advantageously placed in upstream of the first pressure node of the standing wave when it has at least two pressure nodes in the bore. We can also place the cell in a portion of the sound zone where the diameter is greater than or equal to 12.8mm, or place a cell of smaller dimensions.

It is therefore important for this type of saxophone to minimize the bulk of the transducer, of what surrounds and its holding means in the sound zone.

Other features and advantages of the invention will appear on reading the detailed description and accompanying drawings in which: [0061] - Figure 1 schematically shows a saxophone equipped with an example of implementation mode a sound pickup device according to the invention; [0062] - Figure 2 shows schematically in perspective the cell of the device of Figure 1; [0063] - Figure 3 shows schematically in perspective the cell of the device of Figure 2, mounted in the jar of the saxophone of Figure 1; [0064] - Figure 4 shows schematically in more detail the sound pickup device of Figure 1; - Figure 5 shows schematically in section the jar of the saxophone of Figure 1 in which is mounted a sound pickup device according to the invention; - Figure 6 shows in a similar manner to Figure 5, a barrel and a clarinet mouth in which is mounted a sound pickup device according to the invention; [0067] - Figure 7 shows schematically in section and partially, the hole of the clarinet of Figure 6 [0068] - Figure 8 shows schematically in perspective a variant of the cell of the sound pickup device according to the invention; [0069] - Figure 9 shows schematically in longitudinal section the cell of Figure 8 mounted on the tube of a saxophone; [0070] - Figure 10 shows schematically in perspective another variant of the cell of the sound pickup device according to the invention; and [0071] - Figure 11 shows schematically in cross section the cell of Figure 10 mounted on the tube of a saxophone.

In these figures, the same references are used to designate identical or similar elements.

The invention is illustrated below with the aid of an example of a particular embodiment of a sound pickup device.

By way of illustration therefore, this sound recording device is mounted on a saxophone (Figures 1, 3, 4, 5 and 9) and on a clarinet (Figures 6 and 7), but it can be mounted on any wood or even other wind instruments.

As illustrated in FIG. 1, a saxophone, the instrument 1 taken here as a first example, comprises in particular a spout 2, a tube or resonator 3, a spire 4 and keys 5. An example of implementation of FIG. sound pickup device 10 according to the invention is mounted on this saxophone 1.

This pickup device 10 comprises a cell 11 (not visible in Figure 1, see Figures 2 or 5) and a receiver device 12 of the signal transmitted by the cell 11. The receiver device 12 comprises an intermediate housing 13 and a signal processing unit 14. The cell 11 is connected to the intermediate housing 13 by connection means, here a flat cable 15. The intermediate housing 13 is connected to the signal processing unit 14 by a cable 16.

The cell 11 comprises a miniature transducer 17 encapsulated in an elastomeric casing 18 (see FIGS. 5 and 6). The transducer 17 is electrically connected to the flat cable 15. The transducer 17 and the end of the flat cable 15 connected to the transducer 17 are overmolded in the elastomeric envelope 18. The elastomeric envelope 18 thus protects the electrical connection of the moisture and risks of tearing welds between the transducer 17 and the flat cable 15. The elastomeric envelope 18 also preserves the transducer parasitic vibrations (key noises, shocks). As shown in FIG. 2, the elastomeric casing 18 remains open at a vent 19 now in direct communication with the transducer 17 with the air of the bore corresponding to the tube 3. The elastomeric casing 18 is provided with holding tabs 20 which can come into contact with the wall of the tube 3. The holding tabs 20 contribute to isolating the transducer 17 from the wall of the tube 3, thus limiting, on the one hand, the propagation of parasitic vibrations coming from the tube 3 and, on the other hand, the moisture runoff from the wall of the tube 3 to the transducer 17. In addition, a collar 21 prevents run-off on the vent 19. The surface condition of the elastomeric casing 18 can also be studied to limit or prevent this runoff.

The transducer 17 is of the electromagnetic type with a non-conventional architecture, called "balanced armatures" ("balanced armatures" according to the English terminology). This type of architecture favors miniaturization thanks to its high efficiency. Its size can thus be reduced so as to introduce it into the bore without causing any acoustic disturbance degrading the musical qualities of the instrument 1.

This type of transducer 17 is usually used as a transmitter for example in hearing aids for people with hearing loss. But it is used here as a receiver and still able to convert the acoustic signals of the instrument 1 into electrical signals with sufficient amplitude and fidelity. This type of transducer 17 has a non-linear behavior in amplitude and in frequency. The signal obtained at its terminals is thus filtered and processed by the signal processing unit 14 to restore a faithful conversion of the sound of the instrument 1.

This type of transducer 17 has the advantage of not requiring the use of a device for reducing the acoustic pressure. In addition, it has a robustness specific to dynamic transducers, especially in terms of resistance to moisture.

When, as shown in FIG. 3, the cell 11 is placed in the tube 3, the signal generated by the transducer 17 is conveyed out of this tube by the flat cable 15. As illustrated in FIGS. 4 and 5, the flat cable 15 is inserted between the seal 30 mounted on a piece 31 (here the jar) of the instrument 1, and another piece 32 (here the spout). The flat cable 15 must not hinder or degrade the operation of the seal 30 (sealing, sliding parts together).

The thickness of the flat cable 15 is for example at most 0.4mm. In addition, to avoid or limit the disturbances that could cause the flat cable 15 on the acoustic behavior of the bore, is advantageously chosen a flat cable 15 with a width of 1.5mm.

Furthermore, it is advantageous to choose a flat cable 15 whose constituent material of the electrically insulating sheath has mechanical properties of elasticity, resistance and friction favorable to the use made of it in the gripping device. its 10 according to the invention. For example, the constituent material of the electrically insulating sheath is a polyester or polyimide. This sheath may further comprise a conductive layer for shielding against surrounding electromagnetic disturbances.

The intermediate housing 13 is fixed on the outer wall of the tube 3. The intermediate housing 13 provides an electrical connection between one end of the flat cable 15 and a connector 33 more conventional and ergonomic. For example, this connector 33 is a female jack 2.5 or MCX jack. To make the sound pickup device 10 according to the invention and its use more reliable in the stringent conditions of the concerts (installation, speed, stress, etc.), the end of the flat cable 15 and the connector 33 to which it is connected, is overmolded in an intermediate casing 13 made of elastomer. The intermediate housing 13 is made of material (that is to say, formed at the same time into a single piece) with an elastic clamping collar 34. The intermediate housing 13 secures and protects the electrical connection between the end of the cable plate 15 and the connector 33. The collar 34 makes it possible to adapt to different diameters of tube 3 and not to damage the instrument 1.

The cable 16 connecting the intermediate housing 13 and the signal processing unit 14 is an asymmetric shielded cable with, for example, an outer diameter of 3mm. Unrepresented retaining clips may be provided for attaching the cable 16 to the instrument 1 (for example on its linkage), as well as to avoid disturbing the musician, blocking keys, accidentally pulling the connectors, etc. .

The signal processing unit 14 is provided with a clip, spring blade or clip 35 so as to be worn on the belt of the musician or on the instrument 1 (in this case, a support on the instrument 1 may possibly be provided). The signal processing unit 14 has buffer, correction filter, pre-amplification and other functions. The signal processing unit 14 makes it possible to generate a low impedance (<1000 Ohm) output signal, symmetrical or asymmetrical, compatible with the standardized MIC, LINE or INSTRUMENT levels and impedances of an amplifier, a mixer, a a recording apparatus, an effect circuit, etc. The power supply to the signal processor box 14 is powered by batteries or a 9-12V or Phantom Power + 48V power adapter or other devices. The casing 14 is provided with volume and tone adjustment knobs 36 (performing a stamp correcting equalization). However, it should be noted that the tone adjustment may be different or may also be absent from the sound pickup device 10. The electronic circuitry of the signal processor box 14 is entirely analog.

As shown in Figure 6, the sound pickup device 10 according to the invention can be mounted on other instruments 1 that the saxophone. Thus, in this figure, he is mounted on a clarinet. The cell 11 is then placed in the spout 32 and the flat gasket 15 is inserted between the seal 30 of the spout 32 and the barrel 37.

According to a non-represented alternative, the cell 11 is introduced directly into the mouth of a transverse flute.

It is therefore found that the invention also relates more generally to a method of sound recording in a wind instrument, in which a transducer is placed in the bore of this instrument, and a signal is collected outside the resonator. emitted by the transducer, in order to apply to it correction and / or amplification processing.

More particularly, as shown in FIG. 7, the cell 11 is placed in a sound pickup zone 40 defined as being a portion of the bore of the instrument 1, deprived of the acoustic chamber 43, extending , along the axis of the bore, of the exciter 41 of the instrument 1 to a point on the axis of the bore at a distance 44 from the output of the instrument equivalent to the diameter 45 of this exit. In other words, in the case illustrated by FIG. 7, the cell 11 is placed in a sound pickup zone 40 extending, along the axis of the bore, from the outlet of the acoustic chamber 43, up to a point located on the axis of the bore at a distance 44 from the output of the instrument 1 equivalent to the diameter 45 of this output.

According to a variant illustrated in FIG. 8, the cell 11 comprises a deflector 46 and holding means 47 of the cell 11 in the sound pickup zone 40. The deflector 46 consists of an elastomer molded onto the transducer by providing a vent 19. The vent 19 is located under the deflector 46 relative to the holding means 47, to, as illustrated in Figure 9, to prevent condensation 18 from entering the cell 11. The means in the variant illustrated by FIGS. 8 and 9, a retaining clip 47 is made of a clip made of stainless steel partially molded into the elastomer with the transducer 17. The clip 47 is inserted partly between the spout 32 and a seal 30. For reasons of mechanical stress, bulk and corrosion (including galvanic corrosion), it is appropriate to use, for example, a spring-type wire having a diameter less than or equal to 0.5mm (for example 0.2 mm) INOX 302 or a stainless steel spring blade 301 0.1mm thick. To avoid damaging the surface of the parts in contact, it can be provided at least partially the clip of a protective sheath of high strength plastic and low coefficient of friction (for example polyester, polyimide) thin (0.05mm) ).

In addition, metal holding means 47 are used to connect the instrument 1, the transducer 17, a shield connection means 15, the nozzle 32 and indirectly the musician to the electrical ground to reduce electromagnetic interference.

According to yet another variant illustrated in Figures 10 and 11, the cell 11 has fins 50. These fins 50 may have variable dimensions depending on the local dimensions of the bore. For example their wingspan is equal to 2/3 of the local perimeter and the width at their end is equal to half of the local diameter. They can consist of a high-resistance polymer (polyamide, polyester, PEEK, PAI, PI, POM etc.) with a thickness of 0.5mm or less or a metal sheet spring (stainless steel spring, bronze spring) d a thickness of 0.1mm with a protective plastic coating with a thickness of 0.05mm or less.

The device 10 according to the invention may also include many variants, for example: [0095] the receiver device 12 of the signal emitted by the cell 11 may be a single device receiving by a flat cable 15 or by radiofrequency waves the signal emitted by the cell 11; - The communication between the cell 11 and the intermediate housing 13 can be done by radiofrequency waves; - The communication between the intermediate housing 13 and signal processing unit 14 can be done by radio frequency waves; [0098] the clamping collar 34 may comprise loops of different lengths and / or holes of different diameters allowing direct attachment to various types of reed ligation; [0099] the electronic circuit of the signal processing box 14 is partially digital (for the filter part in particular); - The flat cable 15 may be replaced by one or more non-flat cable (s) having for example a diameter less than or equal to 1 mm; [00101] the width of the flat cable 15 may be greater than 1.5 mm, while remaining for example less than 6 mm.

The sound pick-up device according to the invention has many advantages, in particular: [00103] it makes it possible to collect a signal with little parasitic noise and little risk of disturbance by the Larsen effect; [00104] it allows a more faithful reproduction of the sound by freeing itself from the sources of inhomogeneity of sound recording; [00105] it offers the possibility of using effects by electronic signal processing in all simplicity and of producing various acoustic effects, even novel, adapted to contemporary music; [00106] it is easy to install on the instrument, it is removable and ergonomic as to its use; [00107] - it allows to benefit from an internal sound recording without the need to modify the instrument; [00108] - it can allow a quieter play and therefore cause less discomfort for the entourage; [00109] it may allow reed-bar configurations, for woods, which are less restrictive for greater comfort, while compensating for the drop in sound power.

Claims (16)

1. A method of sound recording in a wind acoustic instrument (1), this instrument (1) comprising an exciter (41) and a resonator (3) having an inner shape defining a bore, in which a transducer (17) is provided. ) sensitive to the vibrations of the air column produced by the exciter (41), characterized in that the transducer (17) is placed in a sound zone (40) defined as being a portion of the piercing the instrument (1), deprived of the acoustic chamber (43), extending, along the axis of the bore, the exciter (41) of the instrument (1) to a point located on the axis of the bore at a distance (44) from the output of the instrument equivalent to the diameter (45) of this output. 2. Method according to claim 1, wherein a signal emitted by the transducer (17) is collected by means of a receiving device (12) located outside the bore. 3. Method according to claim 2, wherein the transducer (17), placed in the sound zone (40), and the receiver (12) are connected by means of at least one cable that the one insinuates between two pieces (31,32 or 32, 37) of the instrument (1). 4. Method according to claim 3, wherein the transducer (17) is removably attached to a part (31, 32, 37) of the instrument (1). 5. Device for sound recording in a wind instrument, comprising a transducer (17), a receiving device (12) of the signal emitted by the transducer (17) and connection means (15) between the transducer (17) and the receiver device (12) of the signal emitted by the transducer (17), characterized in that the connection means (15) between the transducer (17) and the receiver device (12) allow communication between the transducer ( 17) and the receiving device (12), when the transducer (17) is placed in a sound zone (40) defined as being a portion of the bore of the instrument (1), deprived of the acoustic chamber ( 43), extending, along the axis of the bore, from the exciter (41) of the instrument (1) to a point on the axis of the bore at a distance (44) of the output of the instrument equivalent to the diameter (45) of this output. 6. Device according to claim 5, wherein the transducer (17) is at least partially overmolded in an elastomeric cell (11). 7. Device according to claim 6, wherein the cell (11) comprises a vent (19) placing in direct communication the transducer (17) and the air of the sound zone (40). 8. Device according to claim 6 or 7, comprising holding means (20, 47, 50) integral with the cell (11), for hanging the cell (11) on the instrument (1), in the gripping zone. of his (40). 9. Device according to one of claims 5 to 8, wherein the receiving device (12) of the signal emitted by the transducer (17) comprises an intermediate housing (13) connected by a wire connection (15) to the transducer (17). and a remote signal processing box (14). 10. Device according to claim 9, wherein the wired connection comprises a flat cable (15). 11. Device according to one of claims 5 to 10, wherein the transducer (17) is electromagnetic type balanced armatures. 12. Wind instrument comprising an exciter (41) and a resonator (3) having an inner shape defining a bore, in which is mounted a transducer (17) sensitive to vibrations of the air column produced by the vibrating reed ( 41), characterized in that the transducer (17) is placed in a sound zone (40) defined as being a portion of the bore of the instrument (1), deprived of the acoustic chamber (43), extending, along the axis of the bore of the instrument (1), from the exciter (41) to a point on the axis of the bore at a distance (44) from the exit of the instrument (1) equivalent to the diameter (45) of this output. 13. The instrument of claim 12, comprising a receiving device (12) of the signal emitted by the transducer (17) placed out of the bore, while the transducer (17) is placed in the sound zone (40). The instrument of claim 13, wherein the transducer (17) in the sounding area (40) and the receiver (12) are connected with a cable inserted at a joint ( 30) between two pieces (31,32 or 32,37) of the instrument (1). 15. The instrument of claim 14, wherein the transducer (17) is at least partially overmolded in an elastomer cell (11) provided with holding means (47, 50) for hanging the cell (11) on the instrument (1). ), in the sound recording area (40). 16. The instrument of claim 15, wherein the holding means (47) are at least partly inserted at a seal (30) between two pieces (31,32 or 32,37) of the instrument (1). ) ·