Closed type receiver with sound-transmitting boundary surface

Abstract

A sound receiving device (5) for mounting within an outer shell of an object (1), the outer shell having a recess (1V), the sound receiving device comprising: a housing (10) disposed within the recess (1V) and forming a hollow space (10H); an acoustically transparent boundary surface (14) enclosing the hollow space (10H); and a sound receiving device (12) disposed within the housing (10) such that a medium is provided between the sound receiving device (12) and the acoustically transparent boundary surface (14).

Description

[Technical field]

[0001] An embodiment of the present invention relates to a closed type sound receiver (sound receiving device) with a sound-transmitting boundary surface for mounting inside the outer shell of an object. A further embodiment relates to a closed type acoustic sensor with a sound-transmitting boundary surface for receiving sound for installation inside the outer shell of an outdoor object or building. The application field of the embodiment is, for example, mobile or movable objects, in particular objects such as vehicles, aircraft and ships, but also buildings. In this respect, a further embodiment relates to the outer wall or wall of a building and a mobile or movable object equipped with a corresponding sound receiving device. [Background technology]

[0002] Sound reception outdoors places particular requirements on the corresponding sensor systems. These must be robust and weatherproof. In addition, it is of utmost importance that such sensors receive as little wind noise or road wind noise as possible. A good aerodynamic profile or measures to reduce wind noise therefore play a key role. Sound reception must remain guaranteed.

[0003] If such a sensor is to be installed in an object located outdoors or moving outdoors (e.g., a freestanding unit or a vehicle), or in front of a house, what exacerbates the situation is the problem of how it can be integrated in a rational way.

[0004] The conventional procedure is to install a microphone in a housing. The microphone is then connected to the outside air through an audio channel (or generally an air path). An acoustic membrane can then be introduced in front of or inside this acoustic channel to protect the microphone from moisture and to prevent dust etc. from entering the channel. This concept is called an "open sensor". The housing is installed or attached inside the outer casing of the object.

[0005] For example, German Patent Application No. 102019220204, which discloses a structure for a microphone, is mentioned as prior art. Such a structure causes problems in the case of strong winds or in the case of relative winds induced at relatively high speeds, for example when a vehicle is moving. Wind noise is induced at sound openings, edges and irregularities. Starting from a certain wind or object speed, the ratio between useful signal and interference noise is shifted to such an extent that the sensor cannot be used even with software to suppress the interference noise (prior art). A further problem is the robustness of the sensor. (The acoustic membrane is significantly easier to damage compared to other stronger / harder materials). A third problem is that the acoustic membrane is adaptively clamped via corresponding electronics / mechanisms, which complicates the described teaching.

[0006] Since there is no barrier (except for the optional acoustic membrane) between the microphone and the outside air, relatively good acoustic reception can be achieved when stationary and in the absence of wind.

[0007] An alternative solution is to place the microphone or the entire sensor behind a fixed casing where no flow or strong pressure fluctuations are expected. In addition, there are fewer issues regarding robustness and weather resistance. In projects where microphones were installed inside vehicles for external noise perception, the following positions, among others, were tested:

[0008] In the passenger compartment (strong interference from the car's occupants and music from the entertainment system), in the exterior mirrors (strong attenuation from the mirrors and mirror housings), in the trunk (strong attenuation from the car body), under the engine hood (strong interference from the engine and other components). All these solutions reduce wind noise by means of isolating materials, but this material does not allow the passage of flows and also attenuates sound waves very strongly, so that the useful signal is also significantly impaired. In addition, noise from the vehicle itself is received more strongly. Therefore, an improved approach is needed. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] DE 102019220204 Summary of the Invention [Problem to be solved by the invention]

[0010] The object underlying the invention is to improve acoustic measurements by means of exterior mounted acoustic measuring devices, in particular with regard to reception quality and robustness at higher mobile speeds. [Means for solving the problem]

[0011] This object is achieved by the subject matter of the independent claims.

[0012] An embodiment of the invention provides a sound receiving device in the shell of an object, such as a building, in the exterior or wall of a building, or even in the shell of a mobile object, such as a vehicle, for example. The shell has a recess, for example in the sense of a recess or notch (for example a hole in which a sensor is integrated with its exterior and housing). -Housing; an acoustically transparent interface; - Equipped with a receiver.

[0013] The housing is placed or embedded in a recess, for example so that a closed shape is obtained. The housing may have a hollow shape. The acoustically transparent interface closes this hollow space. The sound receiver (or microphone) is placed in the housing or hollow space such that a medium is provided between the sound receiver and the acoustically transparent interface.

[0014] An example of a recess is a dent in the facade of a house, or a hole / notch in a car body cladding / sheeting.

[0015] It should be noted that the outer shell forms a kind of surface layer of the object and has a recess open towards the surface. The acoustically transparent interface bounds the housing with the hollow space towards the environment.

[0016] According to embodiments, the medium may include, for example, air, or a material or another gas. According to embodiments, the acoustically transparent interface forms a continuation of the outer shell of the object. It is noted that the acoustically transparent interface constitutes a separate material / object that terminates flush with the surrounding outer surface.

[0017] The embodiments of the invention are based on the finding that a microphone enclosed in a housing, or generally a (enclosed) sound receiving means, can be placed in the recess by means of a corresponding recess. The closed shape of the housing prevents moisture or dust or other solid objects from entering the sensor. The recess can also provide advantages in terms of robustness in the event of an interface having a hole as a result of damage, since due to the distance moisture and dust cannot immediately come into contact with the microphone and the moisture can "trickle down". This has an advantageous effect on the robustness and lifespan of the sensor. In this respect, the embodiments of the invention combine the advantages of a closed system (reduced wind noise, impermeability to moisture or dust) with those of an open system (improved direct sound path between the outside and the microphone and therefore transmission of airborne sound).

[0018] Due to the fact that the continuation of the enclosure is formed by an acoustically transparent interface, a planar surface of the interface can be created together with the perimeter boundary of an object or with the enclosure of an object, such as for example a house facade, so that, in comparison with other solutions, very little wind noise is induced at this surface in the case of a flow or wind, especially since the flow or wind flows past the surface and does not experience inhomogeneities.

[0019] This applies in particular when the flow is parallel to the surface, which is especially the case for faster moving objects, such as vehicles, and in the applicant's opinion, this property is the biggest and most decisive advantage.

[0020] According to a further embodiment, the acoustically transparent boundary surface and / or the outer shell are coated with or provided with a varnish, so that a further advantage is that the acoustically transparent boundary surface can be provided with a varnish and thus is no longer visible in certain objects, for example in the case of vehicles, when the same varnish is used that is also used for the boundary.

[0021] According to an embodiment, the receiving device, in which the medium or at least a part of the medium is formed by a sound-transmitting volume, can be provided with an acoustically transparent interface. As a result of this variant, the acoustically transparent interface becomes particularly robust.

[0022] According to an embodiment, an acoustic insulator, for example comprising sand, bitumen, foam, a polymer chamber and / or further material, is provided between the inside of the housing and the receiver, which has the advantage that noise from the object itself, for example from the engine compartment of a vehicle, is also received by the receiver in a reduced manner.

[0023] In order to provide a consistent connection with the outer shell or the backfill of the outer shell itself, for example by selecting a planar surface or a planar surface provided with varnish, according to an embodiment the housing can be connected to the outer shell via the rear of the housing or to the backfill of the outer shell or the object.

[0024] It is pointed out here that according to the embodiments, the cavity in the housing, or the recess of the housing, or even the housing itself, has, for example, a funnel shape. The funnel shape as one of the possible (inner) shapes is advantageous in itself from an acoustic point of view, further shapes are also possible. The receiver can be arranged, for example, in the last third of the funnel. In some implementations, the funnel shape has the technical advantage that a certain acoustic filtering of the sound from secondary noise is thereby already performed.

[0025] Examples of acoustically transparent interfaces are given below, which may include, for example, one of the following materials:

[0026] -Rigid foam plate -Film-rigid foam plate -PUR or PIR -Plastic plates -HDPE -Highly resistant plastic film -PMMA, PTFE or PET -sheet metal It should be pointed out here that in order to optimize the transition between the sound-transmitting interface and the outer shell of the object, a sealing element, such as for example a rubber lip, may be provided. According to a further embodiment, the sound-transmitting interface may be reinforced or hardened. This may for example have hardened struts. Alternatively, struts for supporting the sound-transmitting interface to the housing are also conceivable. According to a further embodiment, in order to combine the advantages of a rubberized or flexible transition to the exterior and the attachment of the sound-transmitting interface, according to an embodiment the sound-transmitting interface may be attached, for example, to the housing by means of a spring suspension.

[0027] As already explained above, according to the embodiment, the outer shell and the acoustically transparent interface form a planar surface together with the planar transition. In the case of a curved outer surface, it is advantageous that the outer surface is also curved with a corresponding contour. Thus, according to the embodiment, the acoustically transparent interface may have a curved shape. According to the embodiment, the plan view of the recess, and thus the housing, and also the acoustically transparent interface, is, for example, circular or even elliptical. This allows a stress-free attachment at the fulcrum. In theory, other shapes (such as angles) are also conceivable.

[0028] Further embodiments relate to an exterior wall as the object with a sound receiving device or a wall as the object.

[0029] According to a further embodiment, a mobile or movable object, in particular a vehicle, aircraft or ship, is provided with a sound receiving device.

[0030] Embodiments of the present invention are described below with reference to the accompanying drawings. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 is a schematic diagram of a basic implementation of a sound receiving device. [Diagram 2] FIG. 2 is a schematic diagram of an extended embodiment of a sound receiving device. [Diagram 3] FIG. 13 is a further schematic diagram of a sound receiving device according to an extended embodiment for discussing optional features. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Before describing the embodiments of the present invention below with reference to the accompanying drawings, it should be pointed out that like elements and structures are given like reference numbers and therefore the descriptions are mutually applicable or interchangeable.

[0033] FIG. 1 shows an object 1 with an object volume and an object surface 1o. The object can be, for example, a house facade or even the exterior of a mobile object, for example a car. The surface 1o is therefore the topmost terminal layer of the object 1. Starting from the surface 1O, a recess 1v extends into the object body of the object 1. A device for receiving sound, having a housing 10, is arranged in the recess 1V. The device for receiving sound comprises a housing 10 with a receiver 12, for example a microphone, arranged in the housing 10. The microphone is arranged, for example, in the rear wall of the housing 10, i.e. in the cavity of the housing 10. Opposite the rear, the housing 10 comprises an opening 10O arranged in a surface that is substantially continuous with the front, i.e. outer surface 10O, of the housing 10. From a geometrical point of view, this means that the housing opening 10O is substantially continuous with the exterior 1O of the object 1, and the rear of the housing 10 projects into the volume of the object. Sound 20 strikes the exterior 1O and the opening 10O via the front side. This sound can then be received via microphone 12. According to an embodiment, microphone 12 is positioned deep within housing 10, for example in the rear third as viewed from the front 10o.

[0034] The opening 10O is closed by an acoustically transparent interface 14 so that the hollow space 10H in which the microphone 12 is located is enclosed. As a result of the position of the microphone 12 in the hollow space 10H or at the rear of the hollow space, a distance arises between the microphone 12 and the acoustically transparent interface 14, which is filled with a medium, for example air or another gas. The acoustically transparent interface 14 is defined, for example, as a planar body configured to transmit sound. The acoustic boundary layer may have a thickness (as a lower limit), for example, of at least 0.1 mm, at least 0.5 mm, at least 1 mm, at least 2 mm, or even at least 3 mm. The upper thickness limit is, for example, 10 mm or 5 mm or 3 mm or 2 mm or 1.5 mm. Of course, it is also conceivable to fill with a solid or partially solid of a type, for example foam (with pores, i.e. open-pore foam). In the case of a solid material in the hollow space or as the "base" of the acoustic interface, a so-called solid-borne receiver would be reasonable. In part, depending on the embodiment, this can also mean that the region between the acoustically transparent interface and the receiver does not include a solid-filled region in the sense of a hollow space.

[0035] It should also be noted that the solid or partially solid material can be connected (as a separate element) to the acoustically transparent interface. For example, the acoustically transparent interface can be formed by sheet metal, varnished sheet metal, a varnished-bearing layer or a surface element. In other words, the recess can be formed by the surface element (varnished sheet metal like the cladding) that forms the acoustically transparent interface or by the cladding itself.

[0036] A further embodiment is a sound receiving device for mounting within or behind the enclosure of an object, comprising: a housing disposed in the recess at the rear of the outer shell and defining a hollow space; an acoustically transparent boundary surface that is part of the shell and closes the hollow space; A sound receiving device is provided that includes a sound receiver disposed within the housing such that a medium is provided between the sound receiver and an acoustically transparent boundary surface.

[0037] A solid or partially solid material associated with the shell is provided between the acoustically transparent interface and the housing.

[0038] For the structures already described above, the modes of operation are discussed below.

[0039] The outside of the housing 10, i.e., the area where sound 20 impinges on the sound-permeable membrane 14, is encapsulated by a sound-permeable interface or generally interface 14. The sound-permeable properties allow sound pressure to be induced within the interior of the housing 10, i.e., the hollow space 10H, which can be received by the microphone 12. The encapsulation by the permeable interface 14 allows outside air to not come into contact with the microphone 12, thus providing moisture and weather resistance.

[0040] According to an embodiment, the sound-transmitting interface 14 may be continuous according to the surface 10O or may be planarly continuous with said surface. This prevents the formation of co-noises at the transition between the housing 10 and the object 1. For this purpose, according to an embodiment, a sealing element (not shown) may be provided. With regard to the sound-transmitting membrane 14, it is noted that according to a preferred embodiment, it consists of a material that is solid, robust, water-impermeable and weather-resistant, but nevertheless sufficiently sound-transmitting. For this reason, the surface is referred to as a sound-transmitting interface. With regard to the media present outside and inside, it is noted that the sound-transmitting interface can be in contact with air both outside and inside, for example, and according to further embodiments, other media can be used, such as gases, inert gases but also fluids.

[0041] Regarding the microphone, it should be noted that the microphone converts the sound 20 arriving inside the housing 10 into an electrical signal. According to an embodiment, further electronics may also be provided in addition to the actual sensor. Typically, the electrical signal or an electrical signal preprocessed by the electronics is guided outside the housing 10 via a cable. A wireless transmission, for example by radio, is also conceivable.

[0042] An extended embodiment is shown below with reference to FIG.

[0043] 2 shows a sound receiving device 5 having a housing 10, an inner housing 10 or a hollow space 10H of a microphone 12 arranged in the housing, the hollow space 62 being enclosed by an acoustically transparent membrane 14. The housing 10 is embedded in an intermediate material 2 of an object 1, and an inner boundary 2i and an outer boundary 2a are provided within the object 1.

[0044] A contoured recess / hole is located in the boundary 2 and 2a of the mobile or stationary object 1 or house facade, which is in contact with the outside air and in which the acoustic sensor is installed. In this recess a housing 10 is inserted. According to the embodiment the recess is usually, but not necessarily, circular. The housing 10 is inserted in this recess from the inside, usually, but not necessarily, according to the embodiment. According to the embodiment the housing 10 is mounted from the inside, usually, but not necessarily, on the boundary 2a and 2i of the object or house facade.

[0045] According to a preferred, but not required, embodiment, the acoustically transparent interface 14 forms a planar surface together with the peripheral boundary 2a of the object 1 or house facade. The surface 14 is formed from an acoustically transparent material and can be curved or of other shape, depending on the embodiment, for example according to the boundary 2a of the object 1 or house facade.

[0046] Optionally, the housing 10 includes acoustic insulation 22 towards the inside of the object 1 or building 10 to suppress noise from the object 1 or building itself. This acoustic insulation 22 can be implemented in various ways and is therefore not limited in principle to a specific implementation. One example is a filling of sand, bitumen, foam or other material. A further example is several successive chambers of air that can also be filled with foam or sand or similar material. A further type of implementation is layers made of different materials with different resonant frequencies, with or without additional air cushions between the layers.

[0047] According to the embodiment, the inside of the housing 10, in which the sound receiver 12 is arranged, can have different shapes. Acoustically beneficial shapes that allow optimized sound reception are preferred, for example a funnel.

[0048] It should be pointed out here that, according to an embodiment, rigid foam plates of PUR / PIR, with or without additional filming of the surface, such as, for example, brand name Kapa, ​​are suitable as material for the acoustically transparent interface 14. Various solid (i.e. non-flexible) plastics are also suitable, i.e. thin plastic plates, such as HDPE. Various highly resistant plastic films, for example, made of materials such as PMMA, PTFE or PET, are also conceivable. Thin sheet metal is also conceivable. The invention is not limited to a particular group of materials. The materials mentioned represent examples or variations. All materials that meet the requirements stated above also form part of the invention. The thickness of the interface is important in each case. It represents a compromise between robustness or mechanical stability and acoustic transparency.

[0049] As for the receiver, this converts the sound into a voltage or current. All transducer principles are possible here. In an embodiment, part of the acoustic sensor may be further electronics installed in the housing (H). An electronic interface may be part of the sensor. This interface usually, but not necessarily, leads to the inside of the object. Direct guidance of a cable from the housing to the inside of the object or house is also conceivable. It is also conceivable to transmit the acoustic signal via radio.

[0050] Regarding the arrangement of the acoustically transparent boundary surface 14 and the peripheral boundary 2a of the object or house facade, it should be noted that they are preferably provided to form planar surfaces, i.e. flush, so that, in comparison with other solutions, very little wind noise is induced at these surfaces in the event of a current or wind, since the current or wind flows past the surface and does not experience inhomogeneities.

[0051] Regarding the signal quality according to this teaching, it should be noted that according to one embodiment, a compromise is made between closed and open systems: in comparison with an open system, in the absence of wind, the transmission of airborne sound is worse (for the materials considered) (for example, a porous rigid foam plate is still a solid material, and nevertheless transmits poorer than a pure air channel or an acoustic membrane, although the pores allow a better transmission of sound compared to other solid materials), but in the event of wind, for example, the transmission is improved instead.

[0052] In another example / according to a further embodiment, the acoustically transparent interface 14 is supported from the rear (i.e. from the side facing the object or from the side where the receiver is located) by struts of other materials, for example sheet metal or steel. This increases the stiffness and mechanical strength of the interface. The supports can be implemented, for example, in a lattice shape. The supports can allow an interface that is thinner compared to the case without supports and transmits sound better without compromising mechanical strength.

[0053] These supports may thus extend parallel to the acoustic boundary surface 14 as reinforcing structures in the form of bars or grid arrangements. Alternatively, support of the surface 14 against the rear of the housing 10 by vertically or laterally extending supports is also conceivable.

[0054] With reference to FIG. 3, a further embodiment is described, in which it has already been pointed out that the basic structure of variant 1′ in FIG. 3 corresponds to variant 1 in FIG. 2, but additionally there are further optional features.

[0055] In a further embodiment, the medium 26 between the sound-transmitting interface 14' and the receiver 12 is made of a solid material that can transmit structure-borne sound sufficiently well. In this example, the receiver 12 corresponds, for example, to a solid-borne receiver or an acceleration sensor attached to this intermediate material. In a further embodiment, this intermediate material can be the same as the material of the sound-transmitting interface. The sound-transmitting interface is replaced by a sound-transmitting volume.

[0056] In this regard, in this embodiment, the hollow space 26 is filled with a structure that also improves the mechanical robustness of the acoustically transparent interface 14'.

[0057] A further embodiment corresponds to all the previous embodiments in that the acoustically transparent interface 14' is additionally varnished.

[0058] This means that the acoustically transparent interface 14' or the cladding 2a' is varnished with varnish 28. In this case, but not necessarily, the same varnish is usually used for the peripheral boundary if this boundary is varnished.

[0059] A further case / embodiment results from the adaptation of all the previous embodiments, where the housing (if present, but not the sound-transmitting interface) is spring-loaded to achieve improved acoustic isolation against the natural noise of the object or home, where this isolation should be advantageous for the application.

[0060] A further case / embodiment results from the adaptation of all the previous embodiments, in which an acoustic insulation layer, for example in the form of a rubber lip, is additionally placed between the acoustically transparent interface and the boundary or the housing 10 or both, to achieve improved acoustic isolation to the boundary of the object or front of the house, if this insulation should be advantageous in the application.

[0061] A preferred variant (according to one embodiment) is described below starting from the basic and optional features explained above: The structure substantially corresponds to that discussed in Figure 1, with the following additions / variations:

[0062] Microphone as a receiver Film-rigid foam plate with additional varnish as acoustically transparent interface Circular acoustically transparent interface Acoustically transparent interfaces form a planar, smooth surface with the boundary.

[0063] Funnel-shaped housing interior Microphone in the center of the funnel No rubber lips or spring suspension Sand as an acoustic insulation material Applications of embodiments of the present invention include:

[0064] Topic: "Hearing Car" Acoustic external perception / environment detection - Tire rolling noise detection (road surface recognition) - Detection of natural vehicle noise (self-diagnosis, status monitoring) ·others -Detecting noise in the environment · Acoustic monitoring of roads - Prevention of theft of free-standing objects (recording of voice and noise during attempted theft) Detection of environmental noise with simultaneous detection of the noise of the object itself [Explanation of symbols]

[0065] 12 Sound receiver 10 Housing including a holder with a waveguide (housing) 14 Sound-transparent boundary surface (sound-transparent boundary) 22 Acoustic insulation / isolation materials (acoustic insulation materials) 2I,2A boundary 10H Hollow space, e.g. air 2 Intermediate materials (internal materials)

Claims

1. A sound receiving device (5) intended to be mounted within an outer shell (1O) of an object (1), said outer shell (1O) comprising a recess (1V), a housing (10) disposed in the recess (1V) and forming a hollow space (10h); an acoustically transparent boundary surface (14) closing said hollow space (10H); a sound receiver (12) disposed within the housing (10) such that a medium is provided between the sound receiver (12) and the acoustically transparent boundary surface (14); A sound receiving device, wherein a solid or partially solid material associated with said shell (1o) is provided between said sound-transmitting boundary surface (14) and said housing (10).

2. 2. A sound receiving device (5) according to claim 1, wherein the acoustically transparent interface (14) forms a continuation of the outer shell (1o).

3. 3. A sound receiving device (5) according to claim 1 or 2, wherein the medium or at least a part of the medium is formed by a sound-transmitting volume comprising the sound-transmitting boundary surface (14).

4. An acoustic insulation material, in particular an acoustic insulation material including sand, bitumen, foam, polymer chambers, is provided between the inside of the housing (10) and the receiver (12); and / or 4. The sound receiving device (5) according to any one of claims 1 to 3, wherein the inside of the housing (10) is acoustically insulated.

5. The sound receiving device (5) according to any one of claims 1 to 4, wherein the housing (10) is connected to the outer shell (1o) or to a backfilled part of the outer shell (1o) or the object (1) via a rear part of the housing (10).

6. 6. A sound receiving device (5) according to any one of the preceding claims, wherein the recess (1V) and / or the hollow space (10h) of the housing (10) has a funnel shape.

7. The acoustically transparent interface (14) is made of the following material: Film-rigid foam plate, Rigid Foam Plate PUR or PIR Plastic Plate HDPE Highly resistant plastic film PMMA, PTFE or PET 7. A sound receiving device according to any one of claims 1 to 6, comprising one of sheet metal.

8. 8. The sound receiving device (5) according to any one of the preceding claims, wherein the sound-transmitting interface (14) and / or the outer shell (1o) are provided with a varnish.

9. 9. A device according to any one of the preceding claims, further comprising at least one rubber lip at the transition between the sound-transmitting interface (14) and the outer shell (1o).

10. 10. A sound receiving device according to any one of the preceding claims, wherein the acoustically transparent interface (14) is connected to the housing (10) by means of spring suspension and / or mounting.

11. the solid or partially solid material comprises or forms the acoustically transparent interface (14); 11. The sound receiving device according to claim 1, wherein the solid or partially solid material is connected to the sound-transmitting boundary surface (14), or the solid or partially solid material is connected to the sound-transmitting boundary surface (14), the sound-transmitting boundary surface (14) being formed by sheet metal, varnished sheet metal, a varnish-carrying layer or a surface element.

12. the acoustically transparent interface (14) is curved and / or protrudes out of or into the plane; and / or 12. The sound receiving device (5) according to any one of the preceding claims, wherein the sound-transmitting boundary surface (14) and / or the housing (10) and / or the recess (1V) are circular.

13. 13. A sound receiving device (5) according to any one of the preceding claims, wherein the outer shell (1o) and the acoustically transparent boundary surface (14) form a plane or a curved surface or a surface or a curved surface.

14. A sound receiving device (5) to be attached to the rear of an outer shell (1O) of an object (1), a housing (10) disposed in a recess (1V) at the rear of the outer shell (1O) and forming a hollow space (10H); an acoustically transparent boundary surface (14) that is part of the outer shell (1O) and closes the hollow space (10H); a sound receiver (12) disposed within the housing (10) such that a medium is provided between the sound receiver (12) and the acoustically transparent boundary surface (14); A sound receiving device, wherein a solid or partially solid material is provided between said sound-transmitting interface (14) and said housing (10).

15. An exterior wall as object (1) or a wall as object (1) comprising a sound receiving device according to any one of claims 1 to 14.

16. A mobile or movable object (1), in particular a vehicle, aircraft or ship, comprising a sound receiving device according to any one of the claims 1 to 15.

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