The science behind industrial soundproofing: main principles

Soundproofing approaches are critical measures to prevent harmful sound waves from permeating within industrial setting. However, choosing the appropriate strategies depends on different types of noise, essential factors to be considered while designing a safe and efficient industrial workspace.

In this regard, diving into the physics of sound and the relative methods to abate noise levels in industrial settings can be beneficial while selecting the most suitable solution for specific noise-related exigencies.


Types of noise and relative approaches

The noise industrial facility managers and industrial engineers should be concerned about can be divided into three main categories, depending on the means of transmittance: airborne noise, solid-born noise, and impact noise. Each of them requires a tailored approach to mitigation.

Airborne noise is primarily caused to the vibration of the air. More specifically, it refers to sound waves travelling through the air. In this case, the reduction strategy should be drawn on the application of materials that absorb the aforesaid sound waves, such as acoustic panels and soundproofing curtains. These are commonly known as “heat-insulating materials”, since they minimize the noise that is transmitted through the air by literally converting the sound energy into heat energy.

Solid-borne noise, on the other hand, is primarily due to the impact of solids or solid vibrations. The reduction strategy here must take into account the fact that the sound permeates walls, floors, and ceilings with ease. Accordingly, the application of specific vibration isolations materials, such as rubber mats or spring, will be required to absorb or isolate the vibration prior to being transmitted through the structure.

Impact noise, lastly, is produced by physical impacts, including footsteps and machinery vibrations. Similarly to what occurs in solid-borne noise circumstances, the best noise eradication execution can be achieved here by applying materials that absorb impact, such as thick carpets or rubber mats.

It should be also noted that sound permeation is strictly tied tomass law”: the effectiveness of a wall or plate’s soundproofing performance largely depends on how much mass it has in relation to its area. When it comes to selecting sound insulation materials, the higher the mass, the more difficult it is to make it vibrate. Opting for a dense and heavy material is hence, in most of the cases, the best option.

The effectiveness of soundproofing approaches can still vary depending on the frequency and intensity of the noise. Ultimately, a combination of soundproofing materials and techniques may be recommended to effectively reduce noise level and attain sound transmission loss.


The importance of partnering with a specialized soundproofing company

Relying on industrial noise control manufacturer may be game-changing to identify the best materials and techniques to soundproof your industrial setting and fulfill noise mitigation challenges.

Stopson Italiana, which counts on a proven reference list of partners from a variety of industries, certifies an extensive knowledge in providing industrial noise control solution on a global level.

Following an initial consultation path, a team of experts will provide support to identify the source of noise and its type, select the most appropriate soundproofing materials according to its properties, and eventually deliver the solutions that best fit your case. Stopson Italiana offers acoustic panels, sound barriers and vibration isolation materials among them.


We officially announce the birth of Stopson Türkiye

Stopson Italiana merge forces with two Turkish leaders of manufacturing to give birth to Stopson Türkiye, its first foreign entity.


The partnership

The project brings together three companies that were already part of a well-established partnership since 2016: Stopson Italiana, Modcon Makina, and Prodinox Metal.

Stopson Italiana has been pioneering the acoustic sector for more than 50 years designing and manufacturing Silencers and soundproofing solutions, as well as providing engineering support for the energy and industrial market.

Modcon Makina is a young manufacturing organization offering high-quality service packages for industrial facilities, which leverages cutting-edge technology and extensive production know-how with a special focus on carbon steel products.

Prodinox Metal is a company specialized in stainless steel manufacturing, also providing architectural and engineering of facade systems using different technical procedures, primarily focused on leading customers of different sectors such as construction, power, oil, gas, defence and chemicals industries.


The Turkish soundproofing sector

Türkiye’s industrial sector is currently witnessing a rapid growth, especially as regards manufacturing, construction, and energy production.

It is also observed a recent increase of the awareness among Turkish businesses about the essentiality of acoustic insulation to make industrial environments safer, enhance productivity, and decrease noise-related damages.

Against this backdrop, there is an expanding demand for soundproofing solutions designed to tackle noise pollution, also driven by the stricter regulations backed by the Turkish government.


The new company

Stopson Türkiye will therefore benefit from the extensive experience of each of the three players. This collaboration is expected to be a win-win situation for the companies involved with a view toward providing customers with products and services of greater quality and reliability.

Thanks to this partnership, Stopson Italiana’s will introduce its products to the Turkish market. At the same time, the new company will be an option for manufacturing acoustics and related components for Stopson Italiana’s customers at a global level.

We can now proudly combine our different know-hows and join forces into a single, stronger entity to meet all the customer needs.

How to effectively soundproof an industrial HVAC system: some key principles

An examination of the structural factors to take into account in order to tackle HVAC-related noise pollution in industrial facilities.

Industrial HVAC systems play an instrumental part to provide heating, cooling and ventilation to a wide range of facilities such as chemical processing plants, manufacturing facilities, power generation plants and water treatment plants.

They are normally larger and more complex than residential HVAC systems, which makes them also statistically at higher risk of becoming noisy spot.

As a matter of fact, these installations are inclined to produce loud sounds at the damage of the surroundings. It is therefore clear that all the facilities hosting these machines should need to adopt, willy-nilly, a soundproofing strategy in case the hearing comfort of the operating individuals is put in jeopardy.

The initial step of the approach implies the determination of the area where the HVAC systems is installed. Being placed outdoor means, for instance, be arranged for a specific solution over another.

Moreover, as anyone would expect, the location of the HVAC device determines the type of the HVAC equipment. For instance, components such as chillers, fans, cooling towers, and pumps fall within the outdoor HVAC equipment. On the other hand, components such as ducts, junctions, diffusers, and cooling coils are likely to be found inside facilities.

HVAC-related noise control can be engineered by employing two distinct classes of materials: absorptive ones, which naturally absorb sounds, reduce reflections from surfaces and decrease reverberation within spaces, and sound partitions or barriers, which reduce sound transmission between adjacent spaces through non-porous textures, generally recognized as good reflectors of sound.

Reducing noise transmission from outdoor machines requires, firstly, an accurate mapping process of noise propagation. Ventilation of buildings, enclosures and equipment rooms should be meticolously evaluated. Structural factors should be already considered when selecting HVAC equipment and while designing air distribution systems to minimize the noise. The overall design requires, a careful assessment of all the limitations of space, selection of fan, and aerodynamic pressure drops. The final objective is to eradicate the noise created by the flow of air or gas while simultaneously maintaining the flow itself and keeping the pressure drop minimal.

Three main cutting-edge soundproofing technologies provided by Stopson Italiana are suitable to HVAC systems: Acoustic Louvers, Intake Silencers and Acoustic Enclosures. These are indeed durable and easy-to-operate solutions to be integrated as noise control measures into the system design. A series of Silencers specifically designed for HVAC are a perfect fit for applications requiring maximum insertion loss (noise reduction), low static pressure drop, low maintenance, and quick delivery. They can be incorporated into the ventilation system and paired with the machine to fully soundproof it towards all directions.

Explore our news about Industrial Silencer applied to HVAC system to deep dive into the topic.

Stopson Italiana provided EI180 Soundproofing Doors for F1 Test Cells

Stopson Italiana’s case study

Throughout the course of the last two years, Stopson Italiana has concluded the installation of 4 Double Acoustic and Fire-resistant Doors with a single hinged to the benefit of the F1 racing department in Maranello, Modena, Italy.

The 1st door has been delivered in August 2021, the 2nd, and the 3rd door in August 2022, while the 4th in December 2022.

The 4 doors guarantee an EI 180 of classified fire insulation rate and provide a complete sound attenuation as well.

The equipment is composed of external and internal doors.

The former, not exposed to fire, include a casing realized by bended steel plate, closed with a metal sheet on external side and with perforated sheet on the hot side. They have a size of approx. 2400X1800X120 (height*width*thickness).

The latter, directly exposed to fire, have a size of 2300X1500X80 (height*width*thickness).

The Doors are equipped with an insulating core, composed of two layers of thickness rock wool, and with a floating metal sheet placed between the first and the second layers.

Stopson Italiana already partnered to provide a complete soundproofing solution for the same F1 engines test cells in 2004. The recent supply confirms our extraordinary customers return rate as a proof of performance, reliability and definitely leadership in the market.

Stopson Italiana’s soundproofing offering includes internal and external doors for commercial buildings and studios. Stopson Italiana’s fire-resistant and sound attenuation solutions are designed to comply with all the construction regulations according to essential quality, performance, and reliability criteria.

Stopson Italiana wishes you and your team a Merry Christmas and a festive holiday season

Our 2022: as we look back in the year that is about to end, we are very proud to have consolidated our role as one of the global industry leaders.

Our in-depth knowledge of the best soundproofing patterns and engineering practices has allowed us to put a continuous effort to advance products’ performance.

Thanks to our large portfolio of dozens of projects and installations successfully accomplished, we have been able again to confirm our international engagement: also this year, several plants have relied on us to reduce or eliminate noise pollution inside their production setting.


What we expect from 2023: as we look ahead to the coming year, we’re committed to keep innovating to better serve our customers and provide the most reliable soundproofing products and services possible.

We would like to express our gratitude to our customers, communities, partners and other stakeholders for their partnership and support throughout the year.

Best wishes for a Merry Christmas and a “Soundproofed” New Year!

Noise reduction in Pulp Mills and Paper Facilities

Tackling noise attenuation in Pulp Mills: major concepts and challenges

Paper and pulp facilities ordinarily make great use of noisy equipment that is likely to turn into a noise source. In such cases, they need accurate and effective soundproofing strategies.

The major sources in question are mostly vacuum pump exhausts, which are involved in many processes such as machine room ventilation. Nevertheless, a many industry-related processes – including raw material preparation, pulp bleaching, paper manufacturing, and fiber recycling – can be acknowledged as additional causes of high noise pollution in pulp mills.

Potential solutions for noise abatement in Pulp Mills: how can harmful sound be eradicated

The noise control target defines the scope and costs of the soundproofing performances. First of all, costs can immediately be saved (or simply reduced) whether the selected noise control design starts at the early stage of a project.

Secondly, we can achieve results in terms of noise abatement during a further stage which implies deploying absorptive silencers, resonators or enclosures, depending on the noise level requirements.

Active Noise Control (ANC) is another potentially efficient technology for reducing noise in pulp mills, especially at lower frequencies. In ANC action, noise is canceled by sensors and actuators employing ElectroMechanical Film Technology (EMFi), performing as an active element; as a matter of fact, achieving noise reduction at lower frequency making use of passive solutions might be a challenging.

Our offering for Paper and Pulp Mill applications

Stopson Italiana can count on a wide range of products that can represent and ideal solution for Paper Mill applications as well, including Air Filtration, Duct Silencer, Acoustic Enclosures and Barriers, Steam Vent Silencers.

Specifically, our Vent Silencers are thought to reduce the noise level of exhaust piping to the atmosphere for pressurized gaseous fluids, such as air, vapor, natural gas, nitrogen, oxygen, carbon dioxide, etc. They can be installed downstream any device acting as a link between a container of pressurized gaseous fluid and the atmosphere. The Vent Silencer can also provide high or low back pressure relief for the system ensuring proper operation.

Vent Silencers can be reactive, absorptive or combined, depending on applications and required attenuation, which can reach as much as 75 dB(A).

Moreover, Stopson Italiana’s Blow-Off Silencers are currently available for rental in three models that cover the entire range of flow rates:

  • SPM 20-70/B: 20-70 t/h capacity range, from 1.2 bar inlet pressure;
  • SPM 70-120/B: 70-120 t/h capacity range, from 5 bar inlet pressure;
  • SPM 120-250/B: 120-250 t/h capacity range, from 8 bar inlet pressure.

See more about our Silencers here.

The transition towards Advanced Materials in the industrial soundproofing market: a review


In our first article devoted to the topic, we have introduced the theme of the current shift towards the integration of green, sustainable, and advanced materials that might produce some future applications in the soundproofing global backdrop. 

Strengthened by new research, data, and insights, we continue to bring about an in-depth analysis over the transitional phenomena by showcasing some further solutions that have been studied and proposed throughout some of the latest academic contributions.

The purpose of these experimental investigations was to explore the Sound Absorption and Attenuation potential of products and architectures employing alternative materials, which have been already proved to be a valid substitute to traditional solutions.


1. Sound-absorbing Boards made of maize stem

Ramshankar et. al (2021) have developed a research project that studied soundproofing board made from maize stem. This can already be regarded as a beneficial component in those industries where the need to overcome serious noise pollution is regularly encountered, since these structural elements could significantly give a support to eradicate harmful sounds and so reproduce a better working enviroment as well.

The study lies also on the assumption that many of the soundproofing solutions currently available in the market are not so cost-effective. The usage of soundproofing panels based on agro-waste can represent a better solution in such terms too.

Basing their empirical methodology on the Impendance Test, Ramshankar et. al (2021) have drawn the conclusion that, as for maize stalk, the thickness has a very irrelevant influence if we compare it with other natural fibers. At the same time, by comparing different sound absorption co-efficients, it has been observed that maize stalk performs better than several other materials.

However, the most precious insight is that agro-waste panels does not cause any damage to environment, and, additionally, cost of production are also very restricted when compared with other products. Overall, maize stalk as a soundproofing solution succeeds in achieving three main lenses in a all-in-one: cost-efficiency, sustainability, performance.


2. Metamaterials with an eye to naval soundproofing

Metamaterials are made-from-scratch solutions that reach electromagnetic properties which are not normally part of natural elements. D’amore et. al (2022) have investigated a “metasolution” – as it was called in the study – having the potential to replace traditionally adopted solutions especially regarding marine applications. Noise attenuation techniques intended to soundproof marine and naval equipment are indeed becoming an essential asset to ensure the comfort levels required by the standards on board ships. 

As highlighted by D’amore et. al (2022), acoustic metamaterials “are engineered to control, direct, and manipulate sound waves, by transmitting, trapping, and amplifying the sound waves at certain frequencies. This outcome is usually achieved by the periodic repetition in space of an elementary primitive cell, carefully optimized in its topology and geometry”.

Panels made of metamaterials have suitable features, sufficient to be a valid sustainable solution on board ships, especially as an alternative to traditional mineral wool products. This type of solution could pave the way for the slow but unavoidable substitution of traditional solutions for vibration and noise control in other configurations in marine soundproofing.



Stopson Italiana is further growing its awareness of the environmental impact caused by conventional methodologies. It is noted how research and academic studies are largely contributing to powering the transition towards Sustainable Materials by offering plenty of insights. 

It is demonstrated that Advanced and Eco-friendly Materials are already an indispensable resource with a view to better manage not only the complexities of soundproofing execution, but also to make the industry more outcome-centric due to their profitability. Technicians and surface specialist are therefore expected to embrace this knowledge and exploit the opportunities offered by the newest solutions.

The transition towards Sustainable Materials in industrial soundproofing market: a review


As it is occurring in many other industries, the soundproofing global ecosystem is witnessing a shift towards biodegradable materials. Manufacturers are expected to integrate green and sustainable materials with traditional ones while designing their industrial noise control units. It is in fact necessary to bring into line with the ongoing sustainability trends and those requirements set out according to the needs of the present time.

Yet, for a long time now researchers had discovered that natural materials can be effectively used in the construction of sound absorbing architectures with a view to erase noise pollution inside facilities.

However, apart from being required to protect the environmental quality overall, it seems that natural materials can be as effective as conventional solutions.


Preferred Materials: current scenario

As stated by a recent FMI’s study on the state of health of the soundproofing global market polymers and composites still remain the highly preferred materials for the manufacturing of sound proofers. Polymers and composite materials are acknowledged to have higher soundproofing properties as compared to other materials such as glass, metal, and fabric.

Anyhow, the recent developments in composite materials have provided them with the assets of biodegradability and recyclability, which has automatically led to higher sales too. The study estimates that in 2018 alone over 4 out of 10 industrial noise control units made of polymer amd composites have been sold.


Green and Eco-friendly industrial materials

The acoustical natural solutions are still turning more and more into a valid alternative to traditional synthetic applications, as there is much higher effort in developing sustainable absorbers, either from biomass or recycled materials.

In 2021, AcouTech Lab in Tallinn University of Technology delineated a underlying premise: in order to express the noise attenuation potential and achieve the best results in terms of performance, the absorbers’ design should be based on materials with open pores structure, the pores should have small size, and the core material should have high elasticity, while the thickness of the material should be large enough to offer a reasonable attenuation at lower frequencies.

As for conventional materials, absorbers’ performance largely depends on their fibers and structure of pores as well. Cotton fibers have as many noise absorption properties as rock wool and fiberglass do, which are usually employed to realize conventional absorbers. Cotton’s porosity allows it to receive and then contain the sound energy with ease, and plus makes the material compactable, so that designers can form it into thick sheets that ensnare and disperse sound.



Against the current backdrop, soundproofing companies should employ cotton-based materials while developing their products, especially with an eye to reduce echoes and reverberations.

There is a concrete opportunity to launch green product lines including sound proofers such as wall and acoustic panels, baffles and HVAC acoustic liners mostly made from recycled cotton or recycled synthetic fibers.

New emerging technologies designed to mitigate noise pollution within industrial facilities


As largely stressed in many of our past publications, noise can constitute a problematic issue in industrial facilities, regardless of the scope and the type of the plant. Generally technical risk evaluations disregard noise pollution – which is connected to certain negative consequences such as hearing damages and other incidents that lead to severe workplace injuries and illnesses – as a critical hazard, and so noise control as a clear concern and necessary measure. 

Innovative trends based on emerging technologies (and methodologies) cancompensate for the misevaluation of soundproofing in industrial safety. The present article seeks to illustrate four solutions that are bound to revolutionize the industrial control market in the upcoming years.


1. Noise-cancelling windows

The noise pollution originating outside the facilities is probably the trickiest one to be removed. Often it is not possible to identify the source as it occurs for indoor machinery, for instance. A research conducted by a cluster of scholars from Nanyang Technological University of Singapore has found its own way to solve this problem.

The concept revolves around applying a special device – which has been developed by the team taking inspiration from new Apple’s headphones models – to windows and entrances. Such a system will be based on a technology that exploits sensors to detect external noises and counteract the incoming waves, thus obtaining a reduction up to 50%.


2. IoT-based noise attenuation

Traditional soundproofing solutions faced several limitations for mere structural reasons. One of the most common inadequacies related to noise-canceling systems is the lack of time between sensing and emitting. Which benefit could IoT technology bring in this sense? According to many academic studies, an IoT-based system can easily identify the harmful waves spreading by using sound sensors that will block incoming noise producing a counteracting noise itself.


3. Nano-structured foams

Soundproofing experts commonly regard foam materials as a proven solution that pays back in most of the cases. Yet, research has advanced lately to such an extent that using nanomaterials and nano-structured additions will become in the future a regular proposition. All the solutions of this kind dissipate the sounds by converting the vibrations into heat.

Unlike the standard soundproofing foams, these revolutionized foams will be obtained by injection of nanopowder to create from scratch microscopic pores and channels. This solution allows it to absorb noise from 60% to 100% more effectively than traditional foams.


4. 3D-printed Acoustic Rings

Most soundproofing methods work according to some principles of actions. There is generally less space for engineered solutions that deal with passive execution. The 3D-printed metamaterial rings revealed by a group of researchers from Boston University provides a method that redirects noise waves by counteracting vibrations, and they do it thanks to a peculiar design of spiral and circular shape.



The solutions presented above can potentially become game-changing assets in the future. Digitalization of assets can be a robust grip for a transitional trend within the sector. However, it is pretty evident that, so far, new developments have been confined into the realm of concepts and empirical findings. 

As long as they do impact the market, Stopson Italiana will continue to stress the importance of evaluating sources of noise and potential techniques using traditional approaches. Thanks to its extensive knowledge and experience, Stopson Italiana is keen to meet all customers’ requirements and supply comprehensive acoustical solutions in order to achieve their soundproofing goals.


How to implement a successful soundproofing strategy: Fundamental steps and techniques in line with the principles of action


As a matter of fact, noise is regarded as a concrete issue in every industrial facility, and, as a crucial concern, it can easily become hazardous for people around the workspace. For instance, it has been observed that noise may lead the facility’s employees to encounter humming in their ears or have temporary hearing loss. Moreover, an excessively loud environment can easily expose qualified personnel to injury’s risk since noises usually cover alarms or shouted warnings from their co-workers that end-up to be ignored.  

The purpose of the present article is to show many of the options that are adaptable to the most common cases and explore the principles through which noise eradication is obtained when looking into acoustically treating a facility.


Evaluating sources of noise inside our industrial facility

Before ordering an installation, it is advisable to acquire a full understanding of our case. While considering which strategy is the more suitable in order to attenuate harmful sounds, we should first evaluate (1) the source of noise, i.e., the specific piece of equipment that originates the loudest sounds inside the facility, (2) the position and the size of such equipment inside the facility, (3) the operational function of the equipment, as well as its state of preservation. 


Tackling the noise through sound isolation and absorption

Mainly, the noise can be eradicated by isolation or inclusion, or by creating a barrier around the source. Or noise deadening can be obtained by absorption; absorption implies reducing or eliminating echo, reverberation, and amplification within a room, so improving the quality in a limited space, rather than preventing the transfer by separating the source of noise from the rest.


The following solutions are based on the abovementioned principles of action:

  • Acoustic Enclosures are highly effective custom-made solutions that both absorb and block the noise from entering or leaving. Acoustic enclosures are designed to literally enclose any kind of machinery yet are applicable only whether the source of noise can be easily isolated from the rest of the facility. This solution is thus particularly recommended for turbines, auxiliary engines, internal combustion engines and generators sets, mobile generator sets (trailer-mounted) for electric energy production, cogeneration plants, natural gas compression groups, start up and vacuum pumps, blowers, fans, mills, presses, vibrating devices, power transformers and boilers.
  • Comparable to Acoustic Enclosures are Screens and Barriers. While Acoustic Enclosures simply provide protection by isolating the source, screen and barriers are an ideal solution when there is a need to create space between the noise generator and the employees, as they delineate special acoustic shadow-zones. Also, they are composed of sound-absorbing surfaces designed to prevent the increase in noise level towards the source of noise. 
  • Anechoic chambers (AECs) are increasingly used for aircraft engine tests besides being a traditional solution for accurate sound measurement. AECs are indeed perfect when there is a need to completely reduce sound pressure level – to such an extent that reflected signals will be inexistent – in order to acquire the right parameters of precision for measurement.

The importance of receiving a high-quality maintenance process

A further crucial aspect that many tend to underestimate is the state of preservation of equipment that generates noise. Needless to remind that the oldest equipment in the facility needs to be replaced, when necessary, we should take into consideration certain measures, such as oiling and adjusting some critical component on a regular basis. This operation must be carried out by qualified personnel. However, apart from this, it is largely important to rely on professionals in the sector that provide consultancy services and routine checks of the soundproofing applications and make a constantly updated evaluation of their conditions. 

Stopson italiana is the provider you should consider if you are looking for one of the aforementioned solutions. It consolidated itself in the market as one of the main manufacturers of enclosures and control cabins. Moreover, Stopson italiana offers a set of prefabricated anechoic or semi-anechoic chambers, internally treated with standard wedges sized according to the lowest operating frequency, and equipped with a control room.