Soundproofing device

Abstract

A modular soundproofing device comprises at least one non-porous plate-shaped soundproofing element (102) having a first bending eigenfrequency of >50 Hz. At least one stiffening element (106) is mechanically coupled to each soundproofing element (102) to form a closed force loop surrounding the entire perimeter of the soundproofing element. A first bending eigenfrequency of the stiffening element (106) equals or exceeds that of the soundproofing element (102). Further, a viscoelastic interlayer is interposed at every mechanical joint between the soundproofing element (102) and the stiffening element (106). By varying the number, geometry, or spacing of the elements and stiffeners, structural stiffness, surface mass, and acoustic response are precisely tuned. The system delivers high airborne and structure-borne attenuation, particularly from 20 Hz to 200 Hz, with markedly lower surface mass than conventional mass-law solutions and can be incorporated into walls, floors, or ceilings using rigid or elastically decoupled mountings.

Description

[0001] Title: “SOUNDPROOFING DEVICE”

[0002] TECHNICAL FIELD

[0003]

[0001] The present disclosure relates to the field of sound insulation. More particularly, the present disclosure describes a soundproofing device that employs structures and constructions designed to enhance noise reduction and isolation, with a focus on mitigating low-frequency sounds.

[0004] BACKGROUND

[0005]

[0002] The information in this section merely provides background information related to the present disclosure and may not constitute prior art(s) for the present disclosure.

[0006]

[0003] Often, there are environments where it is desirable to achieve high noise reduction, which can be difficult to achieve, especially for lower frequencies. Examples include medical, military, transportation, architectural, recording, filming, event, therapeutic, entertainment, and commercial applications within office buildings, trade show floors, outdoor venues and settings, apartments, condominiums, townhouses, single-family dwellings with little separation between them, and other structures that can be close together or include divisible spaces, interiors, and rooms that can benefit from high noise containment, particularly for lower frequencies.

[0007]

[0004] Other situations might include road construction projects, where a temporary sound wall between a neighborhood and the construction area can be desirable, or even in the case of a military operation, where an aircraft hangar with sound attenuation properties can be deployed during the mission and then removed (or replaced with a permanent structure) when the initial mission is complete.

[0008]

[0005] The impact of sound on humans is perceived differently depending on the frequency. The audible range, where sound sensations are triggered, spans from 16 Hz to 20 kHz, with sound events below 16 Hz classified as infrasound and affecting human health and living organism in particular. Low-frequency sound impacts are perceived as particularly disruptive and can only be mitigated structurally with considerable effort and the use of high mass per unit area.

[0009]

[0006] In conventional building acoustics, standard requirements for the sound insulation of components in noise-sensitive rooms are established that primarily considers frequencies above 100 Hz. However, low-frequency ranges include third- octave bands with center frequencies from 50 Hz to 80 Hz. The standard indicates that disruptive low-frequency noises can extend into the infrasound range and additional measures for sound insulation may be necessary for increased low-frequency noise.

[0010]

[0007] Noises below 20 Hz with high levels can be “felt” (pulsations, vibrations, ear pressure), “perceived” (discomfort, uncertainty, fear), and “heard” (secondary effects due to structure-borne sound transmission, e.g., “glass clinking”). The low-frequency noise components can cause discomfort and health impairments for nearby residents. It is anticipated that the demand for noise protection against low frequencies will significantly increase due to factors such as urban densification, musical events in restaurants, discos and open spaces, increasing neighborhood noise, rising traffic and aircraft noise, and the integration of HVAC systems.

[0011]

[0008] The degree of sound insulation of a soundproofing element (e.g., a panel component) is primarily determined by the mass per unit area used in the component. This is commonly described by the mass law, which states that the sound insulation of a single-leaf panel increases with both mass and frequency. According to this theory, when sound waves impinge on an infinitely large panel, doubling the mass increases sound insulation by 6 dB. For the frequency spectrum, doubling the frequency increases sound insulation, resulting in higher sound insulation at higher frequencies compared to lower frequencies. The simplified approximation equation is as follows:

[0012] Where:

[0013] R = Sound insulation value [dB] f = Frequency [Hz] m' = Surface weight of the plate [kg / m2]

[0014] 0 = Angle of incidence [°] p0= Density of air [kg / m3] c0= Speed of sound in air [m / s]

[0015]

[0010] Another well-known approximation equation is described by the thin plate theory. The application of thin plate theory assumes that the wavelength of the bending waves in the plate is greater than approximately six times the plate thickness. The sound pressure difference across the plate divided by the particle velocity of the plate is described as the plate impedance Zpi. The plate impedance Zpiof an infinitely extended plate, taking into account the bending waves and the coincidence frequency, is calculated as:

[0016] Where: f = Frequency [Hz]

[0017] 0 = Angle of incidence of the plane wave [°] ) = Angular frequency (2 ■ n ■ f) [rad / s] ppi= density of the plate [kg / m3] tpl= thickness of the plate [m] m'pl= Surface weight of the plate [kg / m2]

[0018] Epi= Elastic modulus of the plate [N / m2] rjpl= Mechanical loss factor of the plate [dimensionless] vpi= Poisson’s ratio of the plate [dimensionless] Bpi= Bending stiffness of the plate [Wm] / c_p( = Coincidence frequency of the plate [Hz]

[0019] Clarification on Units:

[0020] For the avoidance of doubt, the unit of bending stiffness Bpiused in this disclosure is Newton-meters [Nm], This corresponds to the plate-based flexural stiffness as derived from thin plate theory. It should not be confused with the flexural rigidity El of beam theory, which has units of [Nm2]. The bending stiffness defined herein is appropriate for plate structures and correctly reflects the resistance against flexural deformation in two-dimensional elements.

[0012] From the above, to increase sound insulation at lower frequencies in a singlelayer construction, the surface mass of the component must be increased. Another common approach to enhance sound insulation involves using the construction made up of two or more plate-like structural elements, arranged with as much distance between them as possible. The space between these elements typically consists of an air gap or gas, often partially or fully filled with a porous insulating material.

[0021]

[0013] According to the Berger Mass Law, doubling the surface mass of a homogeneous material results in an approximate 6 dB improvement in transmission loss. However, in real-world applications, additional factors such as panel stiffness, damping properties, and frequency-dependent behavior influence the actual performance of mass-layer configurations. Table 1 below provides a quantitative comparison of different mass layer configurations in terms of expected transmission loss improvement:

[0022] Table 1

[0023]

[0014] The data in Table 1 shows that the first increase in mass layer, i.e., single layer to double layer, follows the expected “+6 dB” gain according to the Berger mass law. Increasing the mass further, such as by triple layer and quadruple layer, continues to improve transmission loss, however, the increase in the transmission loss is less than the expected improvement in the transmission loss due to structural resonance effects, stiffness variations, and frequency dependent transmission properties. In practical applications, the effect of mass is strongly influenced by damping layers, stiffening structures and composite material behavior.

[0024]

[0015] While the mass law based improvements apply broadly, low-frequency performance remains a major challenge. Below 100 Hz, structural resonance effects can counteract the expected gains from mass layering. Therefore, to enhance soundproofing efficiency at low frequencies, it is often beneficial to combine mass layers with additional stiffeners and damping elements.

[0025]

[0016] Such a construction of two or more masses, coupled with one or more springs, forms a resonant mass-spring system. At low frequencies, the plate-like structural elements oscillate in phase, exhibiting sound insulation properties similar to a singlelayer component. However, within the resonance range of the mass-spring effect, there is a dip in sound insulation. Only above the resonance frequency — approximately 1.41 times the resonance frequency — does sound insulation start to increase again. In double-layer constructions, sound insulation increases by approximately 12 dB to 18 dB per octave, averaging around 15 dB per octave.

[0026] SUMMARY

[0027]

[0017] The one or more shortcomings of the prior art are overcome by the system / assembly / method as claimed, and additional advantages are provided through the provision of the system / assembly / method as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

[0028]

[0018] The present disclosure relates to a modular soundproofing device designed for low-frequency airborne and structure-borne sound insulation. The device comprises a plurality of plate- shaped soundproofing elements, each formed of a non-porous material, and at least one stiffening element mechanically coupled to each of said soundproofing elements. Each soundproofing element is configured to exhibit a first bending eigenfrequency of at least 50 Hz. A key feature is that each said stiffening element, together with its associated soundproofing element, forms a closed force loop that surrounds the entire perimeter of the associated plate-shaped soundproofing element. Furthermore, each said stiffening element has a first bending eigenfrequency that is equal to or greater than that of the soundproofing element and is required to exhibit a bending stiffness of at least 10 Nm, determined under specified measurement conditions.

[0029]

[0019] A viscoelastic interlayer is mandatorily interposed at every mechanical joint between each said soundproofing element and its associated stiffening element. This interlayer is characterized by a specific Shore A hardness range (30A to 80A) and is configured such that the resulting jointed structure exhibits a dynamic loss factor (q) of at least 0.10 in a frequency range from 20 Hz to 200 Hz, serving to absorb vibrational energy, enhance vibrational stiffness, and reduce resonance dips within the low- frequency range.

[0030]

[0020] When a plurality of such soundproofing elements are assembled to form a larger structure, adjacent soundproofing elements are mandatorily mutually decoupled by a specific elastically deformable intermediate layer. This layer, characterized by a Shore A hardness of less than 100A and a static stiffness of 5 N-mm-1 or less (measured at 10 Hz), extends continuously along the full edge length of each adjoining soundproofing element to ensure mechanical decoupling and resonance control.

[0031]

[0021] The soundproofing device is modularly configurable by varying the number, geometry, and arrangement of soundproofing elements and stiffening elements. This allows application-specific adjustment of structural stiffness, surface mass distribution, and vibrational resonance behavior. In various embodiments, the stiffening element may include rib frames, perimeter frame bars, or hybrid structures. The soundproofing element itself may consist of one or more modular plates in user-defined arrangements. A stiffening element may also extend across multiple adjacent soundproofing plates within a soundproofing element.

[0032]

[0022] The soundproofing element may feature varied edge configurations, allowing some edges to be freely displaceable to optimize vibrational response, while other edges may be rigidly coupled to a support frame (often formed by the stiffening element itself). Suitable non-porous materials for the soundproofing element include gypsum, cement, fiber-reinforced polymers, and metal alloys. The stiffening element is affixed to the soundproofing element using methods such as welding, bolting, riveting, adhesive bonding, or mechanical clamping, ensuring a secure and stable connection with the viscoelastic interlayer interposed at the joints.

[0033]

[0023] The soundproofing device can be incorporated into architectural wall, ceiling, or floor structures, where the soundproofing elements act as mass panels. In these applications, the modular devices are combined with support frames and structural reinforcements to enhance low-frequency isolation. For instance, a wall structure may comprise multiple such devices defined with their stiffeners and supported by receiving components; a ceiling structure may integrate them with their stiffeners and ceiling beams; and a floor structure may utilize the devices with their specifically defined (e.g., spring-based or elastically mounted) stiffening elements that fulfill the stiffener requirements of claim 1 while also providing vibration isolation.

[0024] Further, the present disclosure provides a method for manufacturing a soundproofing device that comprises providing the non-porous soundproofing element and the stiffening element with their defined eigenfrequency and stiffness characteristics; mechanically coupling them to form the closed force loop; and interposing the specified viscoelastic interlayer at every mechanical joint.

[0034]

[0025] This combination of a specific closed-loop stiffened structure with defined eigenfrequencies and bending stiffness, mandatory viscoelastic damping at the stiffener-panel interface, and mandatory elastic decoupling between adjacent panel assemblies enables precise control of resonant behavior, particularly in the frequency range below 200 Hz, with significantly reduced overall mass compared to conventional solutions. The device architecture is adaptable to different spatial and acoustic requirements, supporting various connection strategies and empirical design validation.

[0026] Pursuant to an aspect, in an embodiment, a soundproofing device is disclosed. The soundproofing device comprises (a) a plurality of plate- shaped soundproofing elements, each formed of a non-porous material and having a first bending eigenfrequency fl of at least 50 Hz, and (b) at least one stiffening element mechanically coupled to each of said soundproofing elements. In the soundproofing device (i) each said stiffening element, together with its associated soundproofing element, forms a closed force loop that surrounds the entire perimeter of the associated plate-shaped soundproofing element, (ii) each said stiffening element has (1) a first bending eigenfrequency f2 greater than or equal to fl, and (2) a bending stiffness B of at least 10 Nm, measured with respect to a rotational axis perpendicular to a primary extension direction of the stiffening element and parallel to a plane of the associated soundproofing element, said bending stiffness B being determined in a three-point bending test over a span of 300 mm in accordance with either ISO 7438:2016 or ASTM E855, (iii) a viscoelastic interlayer having a Shore A hardness between 30A and 80A is interposed at every mechanical joint between each said soundproofing element and its associated stiffening element, wherein the resulting jointed structure of the soundproofing element, the stiffening element, and the interposed viscoelastic interlayer exhibits a dynamic loss factor r] of at least 0.10 in a frequency range from 20 Hz to 200 Hz, and (iv) adjacent ones of said plurality of soundproofing elements are mutually decoupled by an elastically deformable intermediate layer having a static stiffness of 5 N-mm-1 or less, measured at 10 Hz, said elastically deformable intermediate layer extending continuously along a full edge length of each said adjoining soundproofing element.

[0035]

[0027] In accordance with a non-limiting embodiment of the present disclosure, each said stiffening element comprises a continuous C-shaped metal channel that is welded along the entire perimeter of a corresponding soundproofing plate forming part of the associated soundproofing element, thereby achieving a torsional stiffness of the stiffening element coupled to the soundproofing plate of at least 1x108 N-mm-rad-1.

[0036]

[0028] In accordance with a non-limiting embodiment of the present disclosure, the viscoelastic interlayer comprises a butyl-rubber sheet having a nominal thickness of 3 mm ± 10 %, a Shore A hardness of 60A ± 5, and a mechanical loss factor, expressed as tan 5, of at least 0.25 when measured at 63 Hz.

[0037]

[0029] In accordance with a non-limiting embodiment of the present disclosure, said stiffening element comprises at least one rib frame and / or at least one perimeter frame bar, said rib frame or perimeter frame bar being configured to form or contribute to the closed force loop and being positioned on or integrated with the associated soundproofing element such that it increases the bending stiffness of the soundproofing element and shifts the first bending eigenfrequency fl thereof upward.

[0038]

[0030] In accordance with a non-limiting embodiment of the present disclosure, said stiffening element comprises one or more rib frames and / or one or more perimeter frame bars, said rib frames or perimeter frame bars extending along a plurality of edges of the associated soundproofing element and being joined or configured so as to collectively form the closed force loop as a full perimeter stiffening structure.

[0039]

[0031] In accordance with a non-limiting embodiment of the present disclosure, said soundproofing element comprises a plurality of plate- shaped soundproofing units arranged in a modular configuration, said modular configuration allowing for user- defined assembly of said units tailored to specific acoustic performance criteria.

[0040]

[0032] In accordance with a non-limiting embodiment of the present disclosure, said stiffening element that is mechanically coupled to said soundproofing element extends continuously across at least two adjacent ones of said plate-shaped soundproofing units which constitute said soundproofing element, thereby forming an integrated structural reinforcement that increases an overall bending stiffness of the composite arrangement formed by said units and said stiffening element.

[0041]

[0033] In accordance with a non-limiting embodiment of the present disclosure, at least one edge of said soundproofing element is supported so as to be freely displaceable relative to its associated stiffening element or an external mounting structure during vibrational excitation of the soundproofing element.

[0042]

[0034] In accordance with a non-limiting embodiment of the present disclosure, the remaining edges of said soundproofing element are rigidly attached to sections of its associated stiffening element, said stiffening element thereby acting as a support frame for said remaining edges, and wherein this combination of at least one freely displaceable edge and said rigidly attached remaining edges, together with the viscoelastic interlayer at all mechanical joints, provides the soundproofing element with both mechanical stability and a controlled vibrational response that includes localized decoupling effects.

[0043]

[0035] In accordance with a non-limiting embodiment of the present disclosure, said non-porous material of the soundproofing element is selected from the group consisting of: gypsum, fiber-reinforced gypsum, cement, cement-fiber mixtures, fiber-reinforced polymers, and metal alloys.

[0044]

[0036] In accordance with a non-limiting embodiment of the present disclosure, said stiffening element is affixed to said soundproofing element at the mechanical joints by employing one or more fastening methods selected from the group consisting of: welding, bolting, riveting, adhesive bonding, and mechanical clamping, such that a secure and stable mechanical connection is formed between the stiffening element and the soundproofing element with the viscoelastic interlayer interposed.

[0045]

[0037] In accordance with a non-limiting embodiment of the present disclosure, said elastically deformable intermediate layer has a Shore A hardness of less than 100A.

[0046]

[0038] In accordance with a non-limiting embodiment of the present disclosure, a wall structure comprising at least one soundproofing device is disclosed. The wall structure comprises (a) the plate- shaped soundproofing elements of said soundproofing device serve as mass panels of the wall structure, (b) the stiffening elements of said soundproofing device correspond to wall stiffeners associated with said mass panels, and (c) the wall structure further comprises receiving components configured to mechanically support said at least one soundproofing device and, optionally, frames for media and cable installation channels.

[0047]

[0039] In accordance with a non-limiting embodiment of the present disclosure, a ceiling structure comprising at least one soundproofing device is disclosed. The ceiling structure comprises (a) the plate-shaped soundproofing elements of said soundproofing device serve as ceiling mass panels of the ceiling structure, (b) the stiffening elements of said soundproofing device comprise one or more components selected from the group consisting of: mass panel stiffening ribs and stiffening frames associated with said ceiling mass panels, and (c) the ceiling structure further comprises a plurality of ceiling beams configured to mechanically support said at least one soundproofing device.

[0048]

[0040] In accordance with a non-limiting embodiment of the present disclosure, a floor structure comprising at least one soundproofing device is disclosed. The floor structure comprises (a) the plate- shaped soundproofing elements of said soundproofing device serve as floor mass panels of the floor structure, (b) the stiffening elements of said soundproofing device comprise one or more elastically mounted components, including associated spring components, said elastically mounted components being arranged to support and frame said floor mass panels from below and / or sides thereof and fulfilling all requirements for the stiffening elements, and (c) said elastically mounted stiffening elements and their associated spring components are configured to provide vibration isolation for said floor mass panels in addition to their stiffening function.

[0049]

[0041] Pursuant to an aspect, in an embodiment, a method for manufacturing a soundproofing device having improved low-frequency sound insulation is disclosed. The method comprises (a) providing at least one plate- shaped soundproofing element that is formed of a non-porous material and is designed such that its first bending eigenfrequency fl is at least 50 Hz, (b) providing at least one stiffening element that is designed such that its first bending eigenfrequency f2 is greater than or equal to fl and its bending stiffness B is at least 10 Nm, wherein said bending stiffness B is determined as discussed above, (c) mechanically coupling said at least one stiffening element to said at least one soundproofing element such that: (i) said stiffening element, together with said soundproofing element, forms a closed force loop that surrounds an entire perimeter of said soundproofing element, and (ii) said first bending eigenfrequency f2 of the coupled stiffening element remains greater than or equal to said first bending eigenfrequency fl of the soundproofing element, and (d) interposing a viscoelastic interlayer having a Shore A hardness between 30A and 80A at every mechanical joint formed in step (c) between said soundproofing element and said stiffening element, such that a resulting jointed structure of the soundproofing element, the stiffening element, and the interposed viscoelastic interlayer exhibits a dynamic loss factor r] of at least 0.10 in a frequency range from 20 Hz to 200 Hz; thereby producing the soundproofing device.

[0042] In accordance with a non-limiting embodiment of the present disclosure, said viscoelastic interlayer provided in step (d) comprises a butyl-rubber sheet having a nominal thickness of 3 mm ± 10 % and a Shore A hardness of 60A ± 5, and is configured such that its incorporation results in the jointed structure exhibiting a mechanical loss factor, expressed as tan 5, of at least 0.25 when measured at 63 Hz.

[0050]

[0043] It is to be understood that the aspects and embodiments of the present disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the present disclosure.

[0051]

[0044] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

[0052] BRIEF DESCRIPTION OF FIGURES

[0053]

[0045] The novel features and characteristics of the present disclosure are set forth in the description. The present disclosure itself, however, as well as a preferred mode of use, further objectives, and advantages thereof, will best be understood by reference to the following description of an illustrative embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings wherein like reference numerals represent like elements and in which:

[0054]

[0046] FIG. 1 illustrates a first bending eigenfrequency of a plate of a soundproofing device, the plate being supported on all sides thereof, in accordance with an embodiment of the present disclosure;

[0055]

[0047] FIG. 2 illustrates a first bending eigenfrequency of a plate of the soundproofing device, the plate being clamped on all sides thereof, in accordance with an embodiment of the present disclosure;

[0056]

[0048] FIGS. 3a to 3c depict first three eigenfrequencies of a rectangular plate with all edges free, in accordance with an embodiment of the present disclosure;

[0057]

[0049] FIG. 4 illustrates a first bending eigenfrequency of a plate with all edges free, in accordance with an embodiment of the present disclosure;

[0050] FIGS. 5a to 5d depict soundproofing elements of the soundproofing device, in accordance with different embodiments of the present disclosure;

[0058]

[0051] FIG. 6 illustrates an exemplary wall structure employing the soundproofing device of the present disclosure;

[0059]

[0052] FIG. 7 illustrates an exemplary ceiling structure employing the soundproofing device of the present disclosure;

[0060]

[0053] FIG. 8 illustrates an exemplary floor structure employing the soundproofing device of the present disclosure; and

[0061]

[0054] FIG. 9 depicts a comparison curve of the sound insulation of the known approach for achieving sound insulation from a closed surface made of a single-layer mass, such as a steel layer with a surface mass of 15.72 kg / m2, compared to known double-layer systems that are spaced apart and have a combined mass of 15.72 kg / m2, as well as compared to the present invention, where the surface mass is also 15.72 kg / m2.

[0062]

[0055] Skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the drawings may be exaggerated relative to other elements to help to improve understanding of embodiments of the present disclosure.

[0063] DETAILED DESCRIPTION

[0064]

[0056] The present disclosure may be subject to various modifications and alternative implementations. However, specific embodiments have been presented herein by way of example and are further described in detail with reference to the accompanying figures. It is to be expressly understood that the present disclosure is not limited to the illustrated embodiments, but encompasses all modifications, equivalents, and alternatives that fall within the scope and spirit of the claimed invention.

[0065]

[0057] Prior to describing the embodiments in technical detail, it is emphasized that the novelty and inventive contribution of the present disclosure resides in a modular soundproofing device and a method for manufacturing a soundproofing device as defined by the claims. A person skilled in the art may derive variations or alternative implementations from the teaching provided herein. However, such adaptations are considered to fall within the intended scope of protection as defined by the present disclosure.

[0058] Before describing detailed embodiments, it may be observed that the novelty and inventive step that are in accordance with the present disclosure resides in a soundproofing device and a method for manufacturing a soundproofing device. It is to be noted that a person skilled in the art can be motivated from the present disclosure and modify the various constructions of the soundproofing device and the method. However, such modification should be construed within the scope of the present disclosure. Accordingly, the drawings are showing only those specific details that are pertinent to understand the embodiments of the present disclosure so as not to obscure the present disclosure with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.

[0066]

[0059] In the context of this disclosure, the term “exemplary” denotes an illustration or instance that serves as a non-limiting example. It does not imply that the described embodiment is superior, preferred, or advantageous over other embodiments unless explicitly identified as such in the disclosure or claims.

[0067]

[0060] The expressions “comprises”, “comprising”, and their grammatical variants are to be interpreted as open-ended, indicating that the presence of listed elements does not exclude additional elements. That is, an apparatus comprising specified components may also include unlisted elements that are functionally or structurally compatible.

[0068]

[0061] The expressions “at least one” and “one or more” are to be understood as interchangeable unless the context requires otherwise. Both indicate the presence of a minimum of one element without excluding the possibility of multiple instances.

[0069]

[0062] The term “bending eigenfrequency” refers to the fundamental frequency at which a plate begins to oscillate in a self-reinforcing bending mode. This frequency is a function of mass per unit area, boundary constraints, and bending stiffness. An increase in the bending eigenfrequency typically improves acoustic isolation at low frequencies.

[0070]

[0063] The term “plate impedance” refers to the dynamic mechanical resistance offered by a plate when subjected to incident acoustic waves. It is influenced by the plate’s mass distribution, material damping, and stiffness characteristics. A higher impedance results in reduced energy transmission, thereby enhancing sound insulation.

[0064] The term “stiffener” designates a structural component used to enhance the bending rigidity of a plate and mitigate vibrational excitation. Stiffeners may take the form of ribs, frames, braces, or other reinforcements and are typically configured to raise the system’s natural frequencies and reduce resonance effects.

[0065] The term “mass per unit area” describes the distribution of mass across a plate surface, expressed in kilograms per square meter (kg / m2). According to the mass law, an increase in mass per unit area results in increased transmission loss (i.e., better sound attenuation), particularly in the low-frequency range.

[0071]

[0066] Reference is now made to exemplary embodiments of the present disclosure, illustrated in the accompanying figures. Identical reference numerals are used consistently throughout FIGS. 1 to 9 to denote components with equivalent or identical functions. The following sections describe the embodiments in detail, referring to FIGS. 1 to 9 as applicable.

[0072]

[0067] As disclosed herein, effective low-frequency sound insulation is achieved by constructing the soundproofing device (100) such that its first bending eigenfrequency — i.e., the frequency at which it undergoes its initial bending resonance — is maximized. The device includes at least one soundproofing element (102), typically formed by a bending-elastic plate (104), which may be uniform in thickness or include variable thickness zones depending on the application.

[0073]

[0068] In various embodiments, the plate (104) may be isotropic, anisotropic, or orthotropic, depending on the material’s directional stiffness characteristics. It may be formed as a homogeneous material or as a composite with layered or spatially varying properties. The plate geometry may include flat, curved, corrugated, stepped, or textured surfaces. The structural patterns may be periodic or aperiodic, linear or nonlinear, depending on the acoustic and mechanical requirements.

[0074]

[0069] The plate (104) is composed of a non-porous material and is dimensioned such that its first bending eigenfrequency exceeds the frequency range where enhanced low- frequency insulation is required. As shown in FIG. 9, performance comparisons between the inventive design and conventional systems — e.g., a steel plate with a surface mass of 15.72 kg / m2— demonstrate improved sound insulation over both singlelayer and double-layer reference structures at equivalent mass.

[0075]

[0070] The soundproofing device (100) of the present disclosure employs stiffening elements or stiffeners (106) to prevent dips in sound insulation at lower frequencies caused by resonance and to enhance overall sound insulation. The soundproofing device (100) of the present disclosure aims to achieve a sound insulation improvement of approximately 50 dB at 25 Hz, based on the standard 3 dB = x2 energy rule.

[0076]

[0071] In the context of the present disclosure, it is important to distinguish between the bending stiffness of two-dimensional plate structures, such as the soundproofing element (104), and one-dimensional beam-like structures, such as the stiffening element (106).

[0077]

[0072] Bending Stiffness of the Plate (104) : The term plate bending stiffness, denoted as Bpl, refers to the structural resistance of the soundproofing element's plate (104) to bending deformation. It is calculated per unit width and has the unit of Newton-meters [Nm], For isotropic rectangular plates, it is given by:

[0078] Where:

[0079] Epi= Elastic modulus of the plate material [Nl m2or Pa] tpi= thickness of the plate [m] vpl= Poisson’s ratio of the plate material [dimensionless]

[0080] This definition is appropriate for plate structures and is used in Equations 3, 4, 5, and 6.

[0081]

[0073] Bending Stiffness of the Stiffening Element (106): The term bending stiffness, denoted as B, as used in the claims for the stiffening element (106), also has the unit of Newton-meters [Nm] and represents an effective bending stiffness of the stiffener / stiffening element (106). While stiffeners / stiffening elements (106) like ribs or C-channels are often beam-like structures whose resistance to bending is fundamentally described by their flexural rigidity El (in units of [Nm2]), for the purpose of the present disclosure and for direct comparison with the plate's properties, the claimed bending stiffness B [Nm] is a normalized or effective value.

[0082]

[0074] This effective bending stiffness B [Nm] of the stiffening element (106) is determined empirically from the three-point bending test. From the force-deflection curve obtained in such a test, the fundamental flexural rigidity El [Nm2] of the stiffener can be calculated. The effective bending stiffness B [Nm] can then be derived, for example, by normalizing El with a characteristic width of the stiffener or the soundproofing element it supports. According to the present disclosure, the bending stiffness of the stiffening element (106) is at least 10 Nm that ensures that the stiffening element provides a substantial and quantifiable resistance to bending, directly influencing the eigenfrequency of the assembly.

[0075] Where experimental validation is required, Bpimay be derived either from analytical calculations or by standard test methods such as 3-point bending tests in accordance with ISO or ASTM test protocols.

[0083]

[0076] For the avoidance of doubt, the term “bending stiffness” is equivalent to the flexural rigidity El about the neutral axis of the soundproofing or stiffening element (106), unless otherwise qualified.

[0084]

[0077] As depicted in FIG. 1, the first bending eigenfrequency of a rectangular plate (104) with all edges simply supported (i.e., supported without constraint against rotation) can be approximated using the following analytical expression:

[0085] Where: s_p(_i = First bending eigenfrequency for a simply supported plate [Hz]

[0086] Bpl= Bending stiffness of the plate [Nm] m'pi= Surface weight (mass per unit area) of the plate [kg / m2] a = Length of the plate edge a [m] b = Length of the plate edge b [m]

[0087]

[0079] Further, referring to FIG. 2, the first bending eigenfrequency of a rectangular plate (104) of the soundproofing element (102), where all edges of the rectangular plate (104) are clamped can be approximated using the following equation:

[0088]

[0080] Equation 4 ficjii i = 1 -8296

[0089] Where: c_p(_i = First bending eigenfrequency for a clamped rectangular plate [Hz]

[0090] Bpl= Bending stiffness of the plate [Nm] m'pi= Surface weight (mass per unit area) of the plate [kg / m2] a = Length of the plate edge a [m] b = Length of the plate edge b [m] 1 .8296 = Boundary correction factor for fully clamped conditions [dimensionless]

[0091]

[0081] Furthermore, for a rectangular plate (104) with all edges free, the first three eigenfrequencies result in only rotational movements. Exemplary rotational movements of the rectangular plates (104) for the first three eigenfrequencies are illustrated in FIGS. 3a to 3c.

[0092]

[0082] In accordance with the present disclosure, the first bending eigenfrequency, which is considered for practical purposes, appears at the fourth eigenfrequency. Further, FIG. 4 depicts the first bending eigenfrequency of a plate (104) with all edges free. The fourth bending eigenfrequency of the rectangular plate (104) with all edges free can be approximated using the following equation:

[0093]

[0083] Equation s f4fj)i 4 = 0.70

[0094] Where: f fj)i_ = Fourth eigenfrequency (first practical bending eigenfrequency) for a plate with all edges free [Hz]

[0095] Bpl= Bending stiffness of the plate [Nm] m'pi= Surface weight (mass per unit area) of the plate [kg / m2] a = Eength of the plate edge a [m] b = Length of the plate edge b [m]

[0096] 0.70 = Approximate boundary correction factor for a plate with all edges free [dimensionless]

[0084] According to further embodiments of the present disclosure, the stiffeners / stiffening elements (106) may be applied to at least one side of the plate (104) of the soundproofing element (102) for further sound attenuation. In an embodiment, one or more stiffening elements (106) may be applied to one side of the plate (104). In another embodiment, one or more stiffening elements (106) may be applied to both sides of the plate (104). In further embodiments of the soundproofing device (100), both ends of the stiffeners or stiffening elements (106) may be rigidly connected to the plate (104) in order to further increase sound insulation.

[0097]

[0085] Additionally, the plate (104) of the soundproofing element (102) may be covered with an additional mass layer to increase sound insulation. Said mass layer may be elastic, slack, or plastic. Moreover, cavities in the plate (104) or the soundproofing element (102) may be filled with porous material to further enhance sound insulation.

[0098]

[0086] FIGS. 5a to 5d illustrates exemplary plate (104) of the soundproofing device (100). For example, FIG. 5a illustrates an exemplary plate (104) of the soundproofing element (102). Further, FIG. 5b illustrates a plate (104) with surrounding stiffeners (106), i.e., the stiffening elements (106) being provided as a frame or at the rim of the plate (104). FIG. 5c illustrates a plate (104) with stiffening elements (106) provided in the central portion of the plate (104), for example, rib frames. FIG. 5d illustrates a plate (104) with surrounding stiffening elements (106) and the stiffening elements (106) provided in the central portion of the plate (104). The stiffeners surrounding the soundproofing element (102) significantly affect bending eigenfrequencies of the soundproofing element (102) and overall acoustic performance.

[0099]

[0087] The choice of frame design impacts the distribution of mechanical stress, stiffness, and resonance behavior. Linear rib stiffeners / stiffening elements which run parallel along one or both principal directions (x, y) moderates bending eigenfrequency of the soundproofing element (102) with minimal added mass, therefore, it is suitable for applications where resonance shifts of 10-20% approximate are sufficient. Further, grid and cross bracing stiffeners which are orthogonal and diagonal grid reinforcements significantly increase eigenfrequencies by distributing stiffness evenly, reducing localized flexural resonances, and are thus suitable for high-performance insulation applications.

[0100]

[0088] Furthermore, frame based stiffeners (closed loop design) which are continuous edge stiffening structures enclosing the panel exhibit maximum bending eigenfrequency increase (>50% improvement in bending resistance) and are highly effective for minimizing structural resonance at low frequencies.

[0101]

[0089] A preferred embodiment of such a frame-based stiffener is a continuous C- shaped metal channel that is welded along the entire perimeter of the soundproofing plate (104). This configuration not only provides the closed force loop and high bending resistance but is also designed to achieve a torsional stiffness of at least 1x108 N-mm-rad-1. This high torsional stiffness further contributes to the overall stability of the soundproofing element (102), preventing twisting modes and ensuring a uniform response across the panel surface.

[0102]

[0090] In an embodiment, the soundproofing device (100) may comprise multi-layer hybrid stiffeners / stiffening elements that include combination of ribs and mass layers with constrained damping elements. Said multi-layer hybrid stiffeners / stiffening elements increase eigenfrequencies while also introducing damping effects to reduce resonance dips and improve overall transmission loss. According to the present disclosure, grid and frame-based stiffeners exhibit the highest bending eigenfrequency increases, whereas linear rib stiffeners provide a lightweight alternative with moderate enhancement. However, beyond the internal stiffeners, the structural frame design itself significantly impacts the overall bending eigenfrequency behavior of the soundproofing device.

[0103]

[0091] The structural frame surrounding the soundproofing element (102) significantly affects its bending eigenfrequencies and overall acoustic performance. The choice of frame design impacts the distribution of mechanical stress, stiffness, and resonance behavior. A closed-loop frame structure (where all edges of the soundproofing plate (104) are fixed within a continuous enclosure) significantly increases eigenfrequencies by providing uniform stiffness distribution and minimizing localized resonance effects. In contrast, open-frame configurations (where edges of the soundproofing plate (104) are partially supported or freely oscillating) allow greater flexibility but may introduce lower-frequency resonance artifacts, leading to unwanted dips in sound insulation.

[0104]

[0092] Numerical simulations and empirical testing show that closed-loop frames can increase eigenfrequencies by up to 50% compared to open designs, making them preferable for applications requiring high low-frequency attenuation. The optimal frame choice depends on application- specific constraints, balancing stiffness, damping, and weight. Experimental measurements confirm that the selected stiffening configuration results in a bending eigenfrequency at least equal to, or exceeding, that of the soundproofing element (102), ensuring optimal low-frequency insulation performance.

[0105]

[0093] In accordance with the present disclosure, the first bending eigenfrequency of the plate (104) of the soundproofing element (102) may be equal to more than 50 Hz. In a preferred embodiment, the first bending eigenfrequency of the plate (104) of the soundproofing element (102) may be equal to more than 100 Hz, preferably more than or equal to 200 Hz, more preferably equal to or more than 300 Hz, most preferably more than or equal to 400 Hz. In further embodiment of the present disclosure, the first bending eigenfrequency of the plate (104) of the soundproofing element (102) may vary on a higher end of the spectrum, for example to be equal to more than 500 Hz, preferably equal to or more than 1000 Hz, more preferably equal to or more than 2000 Hz, most preferably equal to or more than 4000 Hz.

[0106]

[0094] Without limiting the scope of protection of the present disclosure, the plate (104) of the soundproofing element (102) may be designed to move freely at the edges thereof, for example, by resting on a ribbed support frame over elastic strips, thus allowing the edges of the plate (104) to lift during vibrational excitation(s). In other embodiments, the plate (104) of the soundproofing element (102) may be supported at the edges, for example by adhesive bonding on a support frame, thus allowing a hingelike movement at the edges of the plate (104). Moreover, to significantly increase the bending eigenfrequency, in some embodiments, the plate (104) of the soundproofing element (102) may be clamped at the edges and / or in the central portion, for example, by welding, riveting, screwing, or rigidly gluing onto a surrounding ribbed support frame, bending the edges of the plate (104) to form a rib or stiffening frame, or by creating a body where the plate (104) with rib frame is formed as a single cast or mold. The geometric form can be made from mechanically deformable materials, thermally fusible or deformable materials, or any materials that may be bonded with stiffening binders. Additionally, in the clamping variant of the plate (104), the plate (104) may be subdivided in the middle areas by rib-like constructions.

[0107]

[0095] Further, the plate (104) of the soundproofing element (102) may be made from pure gypsum or gypsum fiber, cement or cement fiber, or wood materials. The plate (104) may be made by the process of casting, bending or steel welding. Without deviating from the scope of the present disclosure, different materials may be combined and connected using suitable methods to make the plates (104) of the soundproofing element (102).

[0096] Furthermore, the geometry of the plate (104) of the soundproofing element (102) may comprise, but not limited to, at least one of circular design, square design, rectangular design, triangular design, polygonal design, multi-angled design, designs having corners and / or straight lines and / or curves, and designs that are curved inwards and / or outwards.

[0108]

[0097] In some embodiments of the soundproofing element (102), the eigenfrequencies of the plate (104) and the stiffening element (106) may be predicted in advance using finite element method (FEM) simulations, based on their respective geometries and material properties. To validate these predictions, the natural frequencies of both the plate (104) and the stiffening element (106) can be measured experimentally using an accelerometer. In this process, the components) or the plate (104) and / or the stiffening element (106) are securely mounted, and the accelerometer is attached at a representative point. The component(s) or the plate (104) and / or stiffening element (106) are then excited either by an impact hammer or by a shaker with varying frequencies.

[0109]

[0098] The accelerometer measures the acceleration over time. The data are recorded and analyzed, e.g. using Fast Fourier Transformation (FFT), to obtain the frequency spectrum. The peaks in the spectrum correspond to the natural frequencies of the plate (104) and / or stiffening element (106). For validation, these measured frequencies are compared with the frequencies predicted by FEM simulations, or measurements are repeated under different conditions to ensure accuracy. A critical factor in determining these frequencies is the bending stiffness of the stiffening element / rib (106), which directly influences its corresponding eigenfrequency.

[0110]

[0099] Empirical Validation of FEM Simulations

[0111] The present disclosure utilizes Finite Element Method (FEM) simulations to predict the eigenfrequencies of both the soundproofing element (102) and the stiffening element (106). These simulations model the bending behavior of the structural components and provide insight into their dynamic response across relevant frequency ranges. However, since FEM models are based on theoretical approximations, empirical validation is necessary to ensure their accuracy and applicability in real-world conditions. To validate the FEM results, detailed experimental modal analysis is conducted using accelerometer-based measurements. The detailed validation process follows these steps: Preparation of the Test Setup:

[0112] • The soundproofing element (102) or a sample test structure is securely mounted in a controlled test environment to prevent external interference.

[0113] • The component is either suspended in a free-free condition (to isolate bending eigenfrequencies) or mounted similarly to its intended use (e.g., fixed at edges or supported elastically). Excitation of the Structure:

[0114] • The sample is excited mechanically using an impact hammer or electrodynamic shaker, ensuring broad-spectrum frequency input.

[0115] • The force input and the corresponding structural response are recorded simultaneously. Measurement of Eigenfrequencies:

[0116] • One or more accelerometers are attached at critical points on the soundproofing element (102) and stiffening element (106).

[0117] • The vibration response is recorded over time, capturing modal behavior across the target frequency range. Data Processing Using FFT Analysis:

[0118] • The time-domain vibration signals are transformed into the frequency domain using Fast Fourier Transform (FFT).

[0119] • Peaks in the frequency spectrum correspond to experimentally measured eigenfrequencies of the test specimen. Comparison with FEM Results:

[0120] • The experimentally obtained eigenfrequencies are compared to the FEM- predicted values.

[0121] • Deviations, if any, are analyzed to identify potential factors such as material inconsistencies, damping effects, or boundary condition mismatches. Model Refinement & Iterative Adjustment: • If discrepancies exceed a defined threshold (e.g., deviation >5%), the FEM model parameters (e.g., material stiffness, boundary conditions) are adjusted iteratively to achieve better agreement with experimental data.

[0122] • Additional damping parameters may be introduced in the FEM model to account for energy dissipation observed in real-world conditions.

[0123] This combined methodology ensures that the FEM-predicted eigenfrequencies accurately represent the actual behavior of the soundproofing device (100). By bridging theoretical modeling with real- world testing, the soundproofing device (100) is optimized for reliable and reproducible performance in practical applications.

[0124]

[0100] In accordance with the present disclosure, with the bending eigenfrequency of the rib being equal to or more than the plate eigenfrequency, the bending stiffness may be equal to or more than 10 Nm, preferably equal to or more than 20 Nm, more preferably equal to or more than 30 Nm, more preferably equal to or more than 40 Nm, more preferably equal to or more than 50 Nm, more preferably equal to or more than 100 Nm, more preferably equal to or more than 500 Nm, more preferably equal to or more than 1000 Nm, more preferably equal to or more than 2000 Nm, more preferably equal to or more than 4000 Nm, more preferably equal to or more than 8000 Nm, more preferably equal to or more than 16000 Nm, more preferably equal to or more than 32000 Nm, more preferably equal to or more than 64000 Nm, and most preferably equal to or more than 128000 Nm.

[0125]

[0101] For example, the first bending eigenfrequency of the stiffening element (106) in the form of the rib frame, which is clamped on three sides and freely oscillates on one side, may be approximated using the following equation:

[0126] Where: f3sti = First bending eigenfrequency for a rib frame stiffener with specific boundary conditions [Hz] B stiffener = Bending stiffness of the stiffener / rib itself [Nm] m' stiffener = Surface weight (mass per unit area) of the stiffener / rib [kg / m2] a = Length of the stiffener / rib [m] b = Height (or width) of the stiffener / rib [m]

[0127]

[0102] Within the scope of the present disclosure, the soundproofing device (100) of the present disclosure combines sound-absorbing and soundproofing properties using mass panels, i.e., the plates (104) and stiffening elements (106), i.e., the stiffeners (106). The soundproofing elements (102) are arranged to provide effective soundproofing at low frequencies while allowing the installation and integration of sound-absorbing panels. The soundproofing device (100) is modular and adapted to different structural conditions to achieve optimal sound absorption and damping. The construction may be used for walls, ceilings, and floors of a building to ensure comprehensive sound control.

[0128]

[0103] Conventional soundproofing methods typically require a higher mass per unit area to provide effective airborne sound protection, especially against low frequencies. In contrast, the soundproofing device (100) of the present disclosure achieves significant protection against low frequencies without the need for such high mass, offering an innovative approach to sound insulation with a more efficient use of materials. Combined with known solutions for low-frequency vibration isolation, the soundproofing device (100) of the present disclosure ensures excellent overall protection against “low-frequency noise,” providing both effective airborne sound insulation and structure-borne sound isolation for low-frequency vibrations.

[0129]

[0104] Referring to FIG. 6, an exemplary wall structure is illustrated, which is constructed using one or more soundproofing devices (100) as disclosed herein. In this context, the soundproofing elements (102) of the device function as mass panels (W12, W13, W15) and the stiffening elements (106) of the device are realized as the various wall stiffeners / stiffening elements (W1-W6, W14).

[0130]

[0105] The wall structure may comprise mass panels that serve as the main components of the wall structure and are responsible for soundproofing. The mass panels may be supported in the receiving components that improve sound absorption. In FIG. 6, the mass panels may comprise a top wall mass panel (W12), a middle wall mass panel (W13) and a bottom wall mass panel (W15). The receiving components may comprise a bottom section sound absorption panel mounting rail (W7), a top section sound absorption panel mounting rail (W8), and a middle section sound absorption panel mounting rail (W9).

[0131]

[0106] Further, the wall structure may comprise stiffeners / stiffening elements that increase the bending eigenfrequency of the mass panels and thus improve soundproofing. The stiffening elements may comprise a right-side C-frame stiffener (W3), a left-side C-frame stiffener (W4), a lower frame tri-brace stiffener (W5), an upper frame tri-brace stiffener (W6), a bottom stiffener frame (Wl), a top stiffener frame (W2) and a mass panel stiffener (W14). The wall structure may further comprise frames for media and cable channels that enable easy installation and management of media and cable channels. In FIG. 6, said frames may comprise a bottom frame for media and cable installation channel (W16) and a top frame for media and cable installation channel (W17). Furthermore, in the wall structure, fastening elements, for example, screws and / or other fasteners, may be employed to hold the various components of the wall structure together. Exemplary screws may comprise screws (W10, Wi l, W18).

[0132]

[0107] Referring to FIG. 7, an exemplary ceiling structure employing the soundproofing device of the present disclosure is illustrated. The ceiling structure may comprise mass panels that serve as the main components of the ceiling structure and are responsible for soundproofing. The mass panels may comprise a ceiling mass panel (C5) and a mass panel stiffening rib (C6). The ceiling panel may further comprise ceiling beams that not only support the mass panels but also provide a stiffening function for the mass panels. Exemplary ceiling beams comprise a ceiling beam with lower stiffening flange (Cl) and a ceiling beam with upper stiffening flange (C2). Further, the ceiling structure may comprise stiffeners frame for the mass panels that increase the bending eigenfrequency of the ceiling mass panels. The stiffeners may comprise a stiffening frame for mass panels (C3) and a mass panel stiffening rib (C4) + (C6).

[0133]

[0108] Referring to FIG. 8, an exemplary floor structure employing the soundproofing device of the present disclosure is illustrated. The floor structure may comprise mass panels that serve as the main components of the floor structure and are responsible for soundproofing. The mass panels may comprise a central bottom floor mass panel (F5), a corner bottom floor mass panel (F6), a peripheral bottom floor mass panels (F7, F8, F9, F10, Fl l, F12, F13), a central top floor mass panel (F14), a peripheral top floor mass panels (F16, F17, F18, F20), a corner top floor mass panel (F 19) and a central top floor mass panel (F21). The floor structure may comprise components that contribute to vibration isolation and structure-borne sound protection and may include a threaded top plate on elastic spring (Fl), which also serves as a stiffening element, a bottom spring cap with weld nut for height adjustment (F2), a retaining tab (F3), an elastic spring (F4), a 4-unit elastic spring block (F15) and a threaded top plate on elastic single spring (F22), which functions as a stiffening element.

[0134]

[0109] It is a key aspect of this floor structure embodiment that these vibration isolation components, particularly the top plates (Fl, F22), are arranged and potentially interconnected — for example, by the specific layout of the floor mass panels (F5 to F21) they support or by additional frame elements not explicitly shown — in such a way that they collectively function as the stiffening element (106) for their associated mass panel. Specifically, they are configured to form the closed force loop and to provide the necessary bending stiffness (B) and eigenfrequency characteristics. This dualfunction design allows for both high structural stiffness of the panel assembly and excellent vibration isolation from the underlying structure.

[0135]

[0110] The components of the floor structure may be held together by fasteners, for example screws (F23).

[0136]

[0111] In accordance with the present disclosure, the soundproofing device (100) may have a modular design that allows for the combination of multiple layers of soundproofing and sound-absorptive elements to achieve enhanced noise isolation. The modular design may comprise interchangeable components that can be adjusted or replaced to optimize soundproofing performance for different frequencies.

[0137]

[0112] With reference to FIGS. 1 to 9, the present disclosure provides the soundproofing device (100) comprising the plate (104) and / or mass panels that are designed to exhibit high sound insulation performance at lower frequencies when considered individually. Further, the soundproofing device (100) is capable of effectively damping sound energy by minimizing resonance effects in certain frequency ranges. However, when multiple such soundproofing devices (100) are connected to form a continuous structure, resonance dips in sound insulation at low frequencies may occur, particularly when the soundproofing devices are rigidly connected. These resonance dips or effects lead to a reduction in sound insulation performance, which may be undesirable in certain applications.

[0138]

[0113] To counteract the resonance dips in sound insulation when multiple soundproofing devices (100) are rigidly connected, the present disclosure provides for connecting the soundproofing devices either rigidly or elastically, depending on the desired sound insulation characteristics. In accordance with the present disclosure, the elastic connection is preferred to minimize resonance dips or effects at lower frequencies. In this embodiment, elastically yielding materials with a Shore hardness of less than 100A may be employed. These elastically yielding materials may include, but are not limited to, plastics, rubber, elastomers, or other materials that, through their elastic properties, contribute to the damping of resonance artifacts causing reductions in low-frequency sound insulation.

[0139]

[0114] To effectively mitigate resonance dips and optimize low-frequency sound insulation, the connection between multiple soundproofing devices (100) must be carefully designed. While rigid connections provide mechanical stability, they often introduce unwanted resonance effects at low frequencies, leading to dips in transmission loss that negatively impact sound insulation performance.

[0140]

[0115] By contrast, elastic interconnections allow for controlled mechanical decoupling, reducing the formation of standing waves and mitigating resonance artifacts that degrade insulation efficiency. The degree of elasticity plays a crucial role in balancing vibration isolation, stability, and acoustic damping properties. To achieve this controlled mechanical decoupling effectively, the elastically deformable intermediate layer that connects adjacent soundproofing elements (102) is designed to have a specific and low static stiffness. The static stiffness is specified to be 5 Namin ' or less, when measured at 10 Hz. This low stiffness value ensures that structure-borne sound transmission between the elements is minimized, particularly at low frequencies, while still maintaining the overall structural integrity of the assembled device. This is a key parameter that, in conjunction with the Shore A hardness, defines the decoupling performance of the connection.

[0141]

[0116] The elasticity of the connection is determined by the Shore hardness of the interconnecting material, typically an elastomeric layer, rubber compound, or viscoelastic polymer. Empirical studies indicate the following performance trends:

[0142] • Shore 30A - 50A (Soft Elastic Layer): provides maximum decoupling between soundproofing devices (100), reducing structure-borne sound transmission. Said materials are suitable for applications requiring maximum low-frequency isolation, such as recording studios, anechoic chambers, and industrial noise barriers • Shore 50A - 80A (Medium Elastic Layer): balances vibration decoupling with structural stability, reducing resonance dips while maintaining sufficient rigidity for practical installation. Aid materials are suitable for architectural soundproofing, residential, and commercial noise control.

[0143] • Shore 80A - 100A (Firm Elastic Layer): provides partial vibration decoupling while maintaining strong mechanical support. Said materials are suitable for hybrid configurations, where mechanical stability is needed, but some resonance control is still required.

[0144]

[0117] Table 2 below provides a comparison between rigid connections and the elastic connections:

[0145] Table 2

[0146]

[0118] The data in Table 2 indicates that a Shore hardness of < 100A is optimal for reducing resonance dips without excessively compromising structural stability. The impact of elasticity on resonance mitigation depends significantly on the Shore hardness of the interconnecting material. Experimental studies indicate that selecting appropriate Shore hardness levels can optimize the balance between mechanical stability and vibration decoupling.

[0147]

[0119] Empirical tests indicate that materials with a Shore hardness between 50A and 80A provide optimal low-frequency damping, particularly in the range of 20-200 Hz. These materials effectively absorb vibrational energy while maintaining sufficient mechanical stability. In contrast, elastomers with Shore hardness values above 90A exhibit increased rigidity, which reduces decoupling efficiency and can introduce structural resonance artifacts, leading to undesired transmission of low-frequency noise. Experimental results suggest that by selecting Shore hardness values in the 50A-80A range, transmission loss can be improved by 6-10 dB in the critical low-frequency spectrum.

[0148]

[0120] Through the mandatory interposition of this viscoelastic interlayer at every mechanical joint between the soundproofing element (102) and its stiffening element (106), the resulting jointed structure is designed to exhibit a dynamic loss factor (q) of at least 0.10 in the frequency range from 20 Hz to 200 Hz. This quantifiable level of damping is crucial for effectively converting vibrational energy into heat, thereby suppressing structural resonance and contributing significantly to the overall sound insulation performance in the targeted low-frequency range.

[0149]

[0121] Moreover, refinements in material selection can enhance the adaptability of soundproofing devices for diverse environmental conditions, ensuring an optimal balance between mechanical strength and acoustic insulation. For instance, for applications with high-impact noise (e.g., industrial setups), a firmer Shore rating (80A- 100A) is preferred to maintain mechanical strength. Further, for environments requiring extreme low-frequency isolation (e.g., critical listening rooms, theaters), a softer Shore rating (30A-50A) provides the highest decoupling efficiency.

[0150]

[0122] In some embodiments, composite interlayers combining multiple Shore hardness materials may be utilized to optimize performance across multiple frequency ranges. Without limiting the scope of protection of the present disclosure, the elastic connection between the soundproofing devices (100) may be realized through various methods, including, but not limited to adhesive bonding, inserting elastic interlayers, and mechanical clamping.

[0151]

[0123] In adhesive bonding, the soundproofing devices (100) may be bonded with an elastic adhesive that provides both adhesion and flexibility, thereby contributing to the damping of resonance artifacts causing reductions in low-frequency sound insulation. Further, in the inserting elastic interlayers method, elastic layers may be inserted between the soundproofing devices (100), in order to reduce the stiffness of the structure and allow a degree of relative movement between the soundproofing devices (100), thereby reducing resonance artifacts causing reductions in low-frequency sound insulation. Furthermore, in the mechanical clamping method, the soundproofing devices (100) may be mechanically connected through elastic components such as rubber buffers or elastomer mounts, which allow a flexible connection while maintaining the necessary stability.

[0152]

[0124] In accordance with the present disclosure, the connection methods may vary according to the specific requirements of the application. For instance, a combination of rigid and elastic connections may be employed to achieve an optimal balance between structural integrity and acoustic performance. It can be contemplated that the present disclosure allows the soundproofing device (100) to be adapted to different environments and requirements, with a particular focus on controlling and minimizing resonance effects at lower frequencies. Additionally, the soundproofing devices may be combined with additional sound-damping layers or materials to further enhance sound insulation performance. For instance, an additional mass panel may be applied on top of the existing mass panel, or porous materials may be integrated for sound energy absorption. The use of mass-layer systems that influence the resonance frequency of the entire structure can also be employed to optimize performance.

[0153]

[0125] The present disclosure provides a flexible, adaptable solution for sound insulation, particularly characterized by its ability to control and minimize resonance effects in low-frequency ranges. The flexibility makes the soundproofing device suitable for applications where both high sound insulation and adaptability to various acoustic requirements are essential. The soundproofing device (100) encompasses flexible connections, material selection based on Shore hardness, and various methods for connecting the panel elements. Further, the present disclosure provides scope for combining different connection strategies and integrating additional sound-damping layers.

[0154]

[0126] The various embodiments of the present disclosure have been described above with reference to the accompanying drawings. The present disclosure is not limited to the illustrated embodiments; rather, these embodiments are intended to fully and completely disclose the subject matter of the disclosure to those skilled in this art. In the drawings, like numbers refer to like elements throughout. Thicknesses and dimensions of some components may be exaggerated for clarity.

[0155]

[0127] Herein, the terms “attached”, “connected”, “interconnected”, “contacting”, “mounted”, “coupled” and the like can mean either direct or indirect attachment or contact between elements, unless stated otherwise.

[0156]

[0128] Well-known functions or constructions may not be described in detail for brevity and / or clarity. As used herein the expression “and / or” includes any and all combinations of one or more of the associated listed items.

[0157]

[0129] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “includes” and / or “including” when used in this specification, specify the presence of stated features, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, operations, elements, components, and / or groups thereof.

[0158]

[0130] While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other modifications in the nature of the disclosure or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

[0159] REFERENCE NUMERALS EQUIVALENTS:

[0160]

[0131] The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

[0161]

[0132] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and / or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

[0162]

[0133] Any discussion of documents, acts, materials, devices, articles and the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

[0163]

[0134] The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher / lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.

Claims

1. ClaimsWe Claim:

1. A soundproofing device ( 100) , comprising :(a) a plurality of plate- shaped soundproofing elements (102), each formed of a non-porous material and having a first bending eigenfrequency fl of at least 50 Hz; and(b) at least one stiffening element (106) mechanically coupled to each of said soundproofing elements (102); wherein:(i) each said stiffening element (106), together with its associated soundproofing element (102), forms a closed force loop that surrounds the entire perimeter of the associated plate- shaped soundproofing element (102);(ii) each said stiffening element (106) has: (1) a first bending eigenfrequency f2 greater than or equal to fl; and (2) a bending stiffness B of at least 10 Nm, measured with respect to a rotational axis perpendicular to a primary extension direction of the stiffening element and parallel to a plane of the associated soundproofing element (102), said bending stiffness B being determined in a three-point bending test over a span of 300 mm in accordance with either ISO 7438:2016 or ASTM E855;(iii) a viscoelastic interlayer having a Shore A hardness between 30A and 80A is interposed at every mechanical joint between each said soundproofing element (102) and its associated stiffening element (106), wherein the resulting jointed structure of the soundproofing element (102), the stiffening element (106), and the interposed viscoelastic interlayer exhibits a dynamic loss factor r] of at least 0.10 in a frequency range from 20 Hz to 200 Hz; and(iv) adjacent ones of said plurality of soundproofing elements (102) are mutually decoupled by an elastically deformable intermediate layer having a static stiffness of 5 N-mm-1 or less, measured at 10 Hz, said elastically deformable intermediate layer extending continuously along a full edge length of each said adjoining soundproofing element (102).

2. The soundproofing device (100) as claimed in claim 1, wherein each said stiffening element (106) comprises a continuous C-shaped metal channel that is welded along the entire perimeter of a corresponding soundproofing plate (104) forming part of the associated soundproofing element (102), thereby achieving a torsional stiffness of the stiffening element (106) coupled to the soundproofing plate (104) of at least 1x108 N-mm-rad-1.

3. The soundproofing device (100) as claimed in claim 1 or claim 2, wherein the viscoelastic interlayer comprises a butyl-rubber sheet having a nominal thickness of 3 mm ± 10 %, a Shore A hardness of 60A ± 5, and a mechanical loss factor, expressed as tan 5, of at least 0.25 when measured at 63 Hz.

4. The soundproofing device (100) as claimed in claim 1, wherein said stiffening element (106) comprises at least one rib frame and / or at least one perimeter frame bar, said rib frame or perimeter frame bar being configured to form or contribute to the closed force loop and being positioned on or integrated with the associated soundproofing element (102) such that it increases the bending stiffness of the soundproofing element (102) and shifts the first bending eigenfrequency fl thereof upward.

5. The soundproofing device (100) as claimed in claim 1, wherein said stiffening element (106) comprises one or more rib frames and / or one or more perimeter frame bars, said rib frames or perimeter frame bars extending along a plurality of edges of the associated soundproofing element (102) and being joined or configured so as to collectively form the closed force loop as a full perimeter stiffening structure.

6. The soundproofing device (100) as claimed in claim 1, wherein said soundproofing element (102) comprises a plurality of plate- shaped soundproofing units (104) arranged in a modular configuration, said modular configuration allowing for user-defined assembly of said units (104) tailored to specific acoustic performance criteria.

7. The soundproofing device (100) as claimed in claim 6, wherein said stiffening element (106) that is mechanically coupled to said soundproofing element (102) extends continuously across at least two adjacent ones of said plate-shaped soundproofing units (104) which constitute said soundproofing element (102), thereby forming an integrated structural reinforcement that increases an overall bending stiffness of the composite arrangement formed by said units (104) and said stiffening element (106).

8. The soundproofing device (100) as claimed in claim 1, wherein at least one edge of said soundproofing element (102) is supported so as to be freely displaceable relative to its associated stiffening element (106) or an external mounting structure during vibrational excitation of the soundproofing element (102).

9. The soundproofing device (100) as claimed in claim 8, wherein the remaining edges of said soundproofing element (102) are rigidly attached to sections of its associated stiffening element (106), said stiffening element (106) thereby acting as a support frame for said remaining edges, and wherein this combination of at least one freely displaceable edge and said rigidly attached remaining edges, together with the viscoelastic interlayer at all mechanical joints, provides the soundproofing element (102) with both mechanical stability and a controlled vibrational response that includes localized decoupling effects.

10. The soundproofing device (100) as claimed in claim 1, wherein said non-porous material of the soundproofing element (102) is selected from the group consisting of: gypsum, fiber-reinforced gypsum, cement, cement-fiber mixtures, fiber- reinforced polymers, and metal alloys.

11. The soundproofing device (100) as claimed in claim 1, wherein said stiffening element (106) is affixed to said soundproofing element (102) at the mechanical joints by employing one or more fastening methods selected from the group consisting of: welding, bolting, riveting, adhesive bonding, and mechanical clamping, such that a secure and stable mechanical connection is formed between the stiffening element (106) and the soundproofing element (102) with the viscoelastic interlayer interposed.

12. The soundproofing device (100) as claimed in claim 1, wherein said elastically deformable intermediate layer has a Shore A hardness of less than 100A.

13. A wall structure comprising at least one soundproofing device (100) as claimed in any one of claims 1 to 12, wherein:(a) the plate- shaped soundproofing elements (102) of said soundproofing device (100) serve as mass panels (W12, W13, W15) of the wall structure;(b) the stiffening elements (106) of said soundproofing device (100) correspond to wall stiffeners (Wl, W2, W3, W4, W5, W6, W14) associated with said mass panels (W12, W13, W15); and(c) the wall structure further comprises receiving components (W7, W8, W9) configured to mechanically support said at least one soundproofing device (100) and, optionally, frames for media and cable installation channels (W16, W17).

14. A ceiling structure comprising at least one soundproofing device (100) as claimed in any one of claims 1 to 12, wherein:(a) the plate- shaped soundproofing elements (102) of said soundproofing device (100) serve as ceiling mass panels (C5) of the ceiling structure;(b) the stiffening elements (106) of said soundproofing device (100) comprise one or more components selected from the group consisting of: mass panel stiffening ribs (C4, C6) and stiffening frames (C3) associated with said ceiling mass panels (C5); and(c) the ceiling structure further comprises a plurality of ceiling beams (Cl, C2) configured to mechanically support the at least one soundproofing device (100).

15. A floor structure comprising at least one soundproofing device (100) as claimed in any one of claims 1 to 12, wherein:(a) the plate- shaped soundproofing elements (102) of said soundproofing device (100) serve as floor mass panels (F5-F21) of the floor structure;(b) the stiffening elements (106) of said soundproofing device (100) comprise one or more elastically mounted components (Fl, F22), includingassociated spring components (F2, F3, F4, F15), said elastically mounted components (Fl, F22) being arranged to support and frame said floor mass panels (F5-F21) from below and / or sides thereof and fulfilling all requirements for the stiffening elements (106); and(c) said elastically mounted stiffening elements (106) and their associated spring components (F2, F3, F4, F15) are configured to provide vibration isolation for said floor mass panels (F5-F21) in addition to their stiffening function.

16. A method for manufacturing a soundproofing device (100) having improved low- frequency sound insulation, the method comprising the steps of:(a) providing at least one plate- shaped soundproofing element (102) that is formed of a non-porous material and is designed such that its first bending eigenfrequency fl is at least 50 Hz;(b) providing at least one stiffening element (106) that is designed such that its first bending eigenfrequency f2 is greater than or equal to fl and its bending stiffness B is at least 10 Nm, wherein said bending stiffness B is determined as defined in claim 1 ;(c) mechanically coupling said at least one stiffening element (106) to said at least one soundproofing element (102) such that: (i) said stiffening element (106), together with said soundproofing element (102), forms a closed force loop that surrounds an entire perimeter of said soundproofing element (102); and (ii) said first bending eigenfrequency f2 of the coupled stiffening element (106) remains greater than or equal to said first bending eigenfrequency fl of the soundproofing element (102); and(d) interposing a viscoelastic interlayer having a Shore A hardness between 30A and 80A at every mechanical joint formed in step (c) between said soundproofing element (102) and said stiffening element (106), such that a resulting jointed structure of the soundproofing element (102), the stiffening element (106), and the interposed viscoelastic interlayer exhibits a dynamic loss factor r| of at least 0.10 in a frequency range from 20 Hz to 200 Hz; thereby producing the soundproofing device (100) as claimed in claim 1.

17. The method as claimed in claim 16, wherein said viscoelastic interlayer provided in step (d) comprises a butyl-rubber sheet having a nominal thickness of 3 mm ±10 % and a Shore A hardness of 60A ± 5, and is configured such that its incorporation results in the jointed structure exhibiting a mechanical loss factor, expressed as tan 5, of at least 0.25 when measured at 63 Hz.

Images