How Do Acoustic Panels Work

📖 Reading time: 7 min and 7 sec 

Sound absorption is a fundamental concept in acoustics, crucial for creating a comfortable and balanced sound environment. It involves reducing sound energy by converting it into other forms, typically heat. When sound waves encounter a porous surface, such as an acoustic panel, some of the energy is absorbed and dissipated within the material. This process minimises sound reflections and reverberations, enhancing speech clarity. Ultimately, it reduces noise and fosters a better environment for both speaking and listening. 

 

Acoustic Panels Sound Absorption: A Technical Breakdown

Acoustic panels are designed to absorb sound waves. Without these panels, sound waves would reflect off hard surfaces, such as walls and ceilings, creating echoes and reverberation. The most effective acoustic panels are constructed from specialised materials that provide high sound absorption. This means they can efficiently capture and dissipate sound. 

When sound waves strike an acoustic panel, the panel's porous structure allows the waves to enter and convert into heat, primarily through friction. This process reduces the intensity of sound reflections in the room, making it quieter and more acoustically balanced.

 

 

Here's a step-by-step breakdown:

1. Sound Wave Interaction

Sound waves are pressure fluctuations. They move through the air and hit the acoustic panel. Unlike hard surfaces, which reflect these waves, the porous nature of the panel (e.g., foam, felt) allows partial sound penetration.

2. Impedance Mismatch & Energy Dissipation

The abrupt transition from air to porous material creates an impedance mismatch. This mismatch disrupts the sound wave's path. It turns some of its energy into friction within the panel's pores.

3. Resonant Absorption

Depending on the panel design and material properties, resonant absorption may occur. Here, certain sound frequencies match the panel's resonant frequencies. This leads to more energy conversion through vibration. Then, the energy turns into heat.

4. Reduced Reverberation

Sound waves interact with the panel. Their energy diminishes, leading to lower sound pressure and, finally, less reverberation in the space. This means speech will be easier to understand. It will also reduce noise fatigue and create more control over the acoustics.

 

 

Key Considerations

Acoustic panels are designed to absorb sound within a space, reducing reverberation and enhancing clarity. However, they are not effective at blocking sound from passing through walls or other barriers. It's important to focus on soundproofing your space first before considering acoustic treatment. 

 

Porosity & Material

The size of the pores and material properties greatly impact the absorption coefficient (α) of a panel. This coefficient determines how well the panel absorbs specific sound frequencies.

Panel Thickness & Design

The panel's thickness and shape affect its resonant absorption. They allow targeted absorption of specific frequencies.

Placement & Application

The placement of panels in a space is crucial. It must be strategic and consider factors like sound source and paths. This is to achieve the best acoustic control.

 

 

Types of Acoustic Panels and Their Effectiveness

There are several main types of acoustic panels. Each has unique traits and is good at absorbing sound.

Why Technical Data Matters? Acoustic metrics like Noise Reduction Coefficient (NRC) and absorption coefficients are derived from standardised testing (e.g., ASTM C423, ISO 354) and represent averaged sound absorption across key mid-frequency bands, typically 250 Hz to 2000 Hz.

Although NRC is useful for general comparisons, spaces with critical acoustic needs (like studios) often require frequency‑specific data for accuracy.

For better low-frequency absorption, increasing material thickness or adding airspace behind panels significantly improves performance, often more than just increasing surface area. 

 

Perforated Wood Panels

Acoustic wood panels are made from high-quality wood veneer, and some of them are specially engineered with PET Felt backing (e.g. wood slatted panels, HexyBEL). Thanks to micro‑perforations or slatted designs, they offer exceptional sound absorption, particularly in the mid-range frequencies of 300–600 Hz., often achieving NRC ratings between 0.65 and 0.90, with Class A performance possible in optimised configurations. That makes them ideal for performance venues or feature wall installations where warmth meets functionality.

 

 

Fabric-Covered Panels

Built around a dense foam core, covered in acoustical fabric, these textile acoustic panels are high‑performance absorbers with NRC values typically ranging from 0.70 to 1.00, depending on thickness (e.g. 1″ ≈ 0.8, 2″ ≈ 1.0). They deliver broad frequency absorption, especially in mid and high ranges, making them a popular choice in offices, studios, and hospitality interiors for speech clarity and reverberation control. 

PET-Felt Panels

Eco‑friendly and durable, PET‑felt panels, typically recycled polyester fibre, achieve NRC values between 0.7 and 0.88, with some denser variants reaching up to 1.00 – 1.10 depending on thickness, density, and mounting depth. They are excellent for sound absorption across mid‑high frequencies and are often used in both residential and commercial interiors. 

 

 

Ceiling Baffles

Suspended acoustic panels hung from ceilings absorb sound from both sides. Often made from foam or fabric‑wrapped materials, their NRC typically ranges from 0.70 to 0.90 depending on thickness and mounting configuration. Hanging baffles combat flutter echoes and reverberation in large open spaces like lobbies or atria.

Foam Sound Absorbers

Open-cell acoustic foam (e.g. wedge or pyramid foam) is lightweight and effective for mid‑ and high‑frequency absorption. Their open-cell foam structure allows sound waves to pass through. NRC typically ranges 0.65–1.00 depending on thickness (1″ foam ~0.65 NRC; 2″ ~1.0). Its economy and ease of installation make it common in recording setups and home theatres. 

Bass Traps

Specialised absorbers like bass traps, often placed in corners, are designed to tame low-frequency buildup (below 250 Hz). Packed with dense, deep absorptive material (e.g., fibreglass or high-density foam). A well-designed bass trap can significantly reduce modal ringing and improve low-end balance. NRC might be moderate on paper (~0.50–0.70), but effectiveness at low frequencies is what matters.

 

 

Diffusers

Diffusers don’t absorb sound, they scatter it in multiple directions, breaking up reflections and promoting a more natural ambience. Typically used alongside absorbers to refine acoustic space and balance live vs. dead elements. Not rated with an NRC but essential for precision acoustic design with optimal sound control and balance. 

Choosing the Right Acoustic Panels

When selecting acoustic panels, it is important to consider multiple factors. This ensures that the panels function effectively and appear aesthetically pleasing. Here are some key points to keep in mind:

 

Acoustic Performance 

Determine the level of sound absorption needed based on the size and function of your space. Higher-density panels offer better sound absorption and are ideal for noisy environments.

Aesthetic Appeal

Choose panels that complement your interior decor style and enhance the overall ambience of your space. Select a sleek contemporary design that seamlessly integrates with any design scheme.

Installation Method

Consider the mounting options for acoustic panels. Choose the one that best suits your needs and preferences. Installation methods can vary. They include glue, tape, screws, hooks, etc. They provide versatility and ease. 

Environmental Impact

Choose eco-friendly acoustic panels. They are made from sustainable materials. They help you reduce your carbon footprint and support environmental conservation. 

 

 

Installation and Placement Tips for Maximum Sound Absorption

Correctly install and position acoustic panels, as they are essential for absorbing sound and enhancing the acoustics of a space.

 

• Identify problem areas

Start by identifying the areas in the room where sound reflections and echoes are most noticeable. These are typically large, flat surfaces like walls, ceilings, and windows.

• Coverage

Determine the amount of coverage needed based on the size of the room and the desired level of sound absorption. In general, it is recommended to cover around 25-50% of the total wall and ceiling surfaces with acoustic panels.

• Placement

Strategically place the panels in the identified problem areas to minimise sound reflections. Consider placing panels at the first reflection points. These are the spots where sound waves first hit a surface after leaving the sound source. This includes the corners of the room, wall-ceiling junctions, and wall-floor junctions.

• Spacing

Follow the specific instructions for each product. They say how much space to leave between the panels. This helps absorb low-frequency sounds. It stops sound from getting trapped behind the panels.

• Experimentation

Fine-tune the placement of the panels by experimenting with different configurations. Consider using both absorption and diffusion panels. They create a balanced sound environment.

Interested in the optimal placement of acoustic panels in your music studio? Check out the expert tips from our acousticians in the article HERE.

Follow these installation and placement tips. They will help you maximise the sound absorption of acoustic panels. They will also improve your space's acoustics.

 

 

Benefits of Using Acoustic Panels in Different Settings

Acoustic panels offer many benefits. They work in homes, offices, and schools.

1. Improved sound quality

Acoustic panels reduce echoes and reverberation. This improves sound clarity and intelligibility. This is key in spaces where communication is crucial. These spaces include conference rooms, classrooms, and podcast or recording studios.

2. Noise reduction

Acoustic panels absorb sound waves. They reduce unwanted noise and make an environment more peaceful and comfortable. This is beneficial in settings such as offices, restaurants, and healthcare facilities.

 

 

3. Aesthetical appeal

Acoustic panels come in many designs, colours, and finishes. They let you choose options that complement your space's look. They can be customised to blend seamlessly with the interior design or serve as decorative elements.

4. Versatility

You can install acoustic panels on walls or ceilings. You can also use them as freestanding partitions. They are flexible in where and how you can place them. They can be easily removed or repositioned as needed.

5. Safety and compliance

In some settings, like schools or healthcare facilities, acoustic panels can help. They can meet safety and compliance rules by cutting noise and ensuring good acoustics.

Adding acoustic panels to different settings brings these benefits. It also creates a more comfy and useful space.

Studies have shown that panels can reduce reverberation time with acoustic treatment. This improvement leads to better student performance in classrooms. Also, the National Institute for Occupational Safety and Health did research, showing the bad health effects of workplace noise and underscoring the need for good sound absorption.

Did You Know…?

• Air cavities enhance low‑frequency absorption

Porous acoustic materials often underperform below 1000 Hz unless backed by an air cavity of ~¼ wavelength; for 300 Hz, that means around 29 cm spacing for effectiveness.

• Micro‑perforated panels can outperform thick insulation

Using tiny perforations (0.1–1 mm) and tuned cavity depth, these panels absorb a wide frequency bandwidth while remaining thin and stylish.

• PET‑felt acoustic panels are made from recycled bottles

Panels made from recycled PET (like virtual material tech panels) offer comparable absorption and colourful aesthetics, combining sustainability with sound performance.

• Eco‑friendly acoustic panels made from mushrooms are emerging

Mycelium‑based panels have shown comparable absorbance above 3000 Hz to foam and felt, though low‑frequency performance still lags.

• Foam is only effective at absorbing high frequencies

Basic foam panels significantly reduce echo in treble ranges, but struggle to absorb mid‑low frequencies (<500 Hz) unless combined with other materials.

 

 

Do you need more assistance in taking the right decision and improving your environment acoustically? Drop us a line.