A Complete Guide to Specifying Acoustics

A Complete Guide to Specifying Acoustics

Acoustics play a vital role in modern spaces, whether it's a commercial building, educational institution, or residential property. With the increasing popularity of open-plan designs and the incorporation of technology, it is essential to create a balance between functionality and acoustic performance. Poor acoustics can result in increased stress levels, reduced productivity, and even physical health issues such as hearing damage, sleep disturbance, and headaches.

Acoustics also play a critical role in creating the right atmosphere in various settings. For instance, in a restaurant, the acoustics need to be conducive to conversation while creating an ambience that enhances the dining experience. In contrast, a concert hall requires acoustics that enhance the sound quality and clarity of the music while providing an immersive experience for the audience. In short, proper acoustics can positively impact the mood, behaviour, and experience of people in various spaces.

Achieving a visually appealing space is also important, of course, but it's equally crucial to create an environment that feels comfortable and inviting.

Acoustic panels can be installed to absorb sound waves and minimise reverberation, thereby improving the overall atmosphere of a room. This is particularly critical in office and educational facilities, where noise levels can affect productivity and inclusivity.

Understanding the Basics of Acoustics

The Role of Acoustic Panels

Acoustic panels work by absorbing sound waves and reducing noise.

Sound waves can be reflected or absorbed, and the science of acoustics is largely about what to reflect, what to transmit, and what to absorb.

Sound travels until it meets resistance (for example a wall), at which point it reflects off. Acoustic panels work by absorbing this sound, subsequently making a space quieter to be in.

Acoustic panels vary in material and design; each of these elements works differently to manage sound absorption (or reflection).

At Decor Systems, we have an extensive range of acoustic panels to suit the needs of any space both from a sound management and aesthetics point of view.

Key Acoustic Terminology

There are some key terms to understand when specifying acoustic panels. We go into detail about these in our CPD presentations which you can book through one of our project consultants but we’ve pulled out the top terminology below to keep in mind as we move through this article. You can view the full acoustics glossary here.

Decibel

A unit of measurement used to express the intensity of sound. The Noise Reduction Coefficient (NRC) rating of an acoustic panel measures its effectiveness at reducing sound levels, with higher NRC ratings indicating greater sound absorption and reduced sound transmission.

Echo

A reflected sound wave that arrives at the listener's ear after the direct sound wave. Acoustic panels can reduce echoes and improve speech intelligibility by absorbing sound waves and reducing their reflections.

Frequency

The number of cycles of a sound wave that occur in one second, measured in Hertz (Hz). Acoustic panels can be designed to absorb specific frequencies, such as the frequencies of human speech or music, to improve the clarity of sound in a room.

Pitch

A subjective perception of the frequency of a sound wave, ranging from low to high. Acoustic panels can help to improve the overall acoustics of a space by reducing the variation in pitch caused by reflections and echoes.

Reverberation

The persistence of sound in a space due to repeated reflections and scattering of sound waves. Acoustic panels can reduce reverberation time by absorbing sound waves and reducing their reflections, which can improve speech intelligibility and reduce background noise.

Sound wave

A disturbance that travels through a medium, such as air, and carries energy from one point to another. Acoustic panels work by absorbing sound waves, which reduces their energy and prevents them from bouncing around a space, thereby improving the acoustics of the room.

Acoustic Treatment Solutions

What are Acoustic Panels Made From?

Acoustic panels are made from a variety of different materials including timber, fibre cement, plasterboard, and wood wool.

Each comes with a different acoustic rating and is suitable for a variety of applications. Acoustics need to be managed differently in different spaces, for instance, in a library compared to a music room.

Most acoustic panels are made from a combination of timber with a sound-absorbing backing material that is made from an absorptive material.

Balancing Acoustics and Aesthetics

At Decor Systems, we try to strike a balance between acoustic panels that not only manage sound but are aesthetically pleasing. So, once you select the rating and provide our project consultants with a brief on what you’re trying to achieve, the Decor team can work with you to create a solution that blends in with the aesthetics of the space you are designing.

When it comes to specifying acoustics, there are many factors to consider. Decor Systems should be viewed as an extension of your team so we can work together to ensure that you achieve exactly what it is you’re after.

Factors to Consider When Specifying Acoustics

To ensure successful sound performance in your project, it is crucial to plan ahead and define your requirements during the conceptual stage. Retrofitting acoustic panel systems can be expensive, time-consuming, and may result in a "Band-Aid" look. Therefore, potential issues should be analysed beforehand to address them intelligently at the appropriate time.

Here are some things you need to know to scope out your requirements properly.

• Room dimensions
• Ceiling height
• Type of lighting
• Ventilation/ductwork
• Fire rating requirements
• Environmental accreditations required
• Potential issues
• New build or retrofit?
• Current sound treatments

Identify your main sound issues, which can be divided into two parts: absorption treatment and isolation treatment.

Absorption treatment

It is essential to determine the correct level of absorption required. Light, moderate, and heavy absorption are the three levels, with 5% - 25%, 25% - 50%, and 50% - 60% coverage needed respectively. It is crucial to position the absorption materials evenly around the treated space, exposed to the source of the noise problem.

Isolation treatment

You can look for areas where sounds may be escaping, such as doors, windows, ductwork, and vents. Employing thicker, less compressed materials can help reduce impact and vibrational noise. Thinner, denser materials are better suited for sound isolation. It is recommended to "seal" the room by covering every surface with an appropriate sound isolation material to prevent sound from escaping or entering.

14 Considerations When Specifying Acoustic Wall and Ceiling Linings

1. Understand the acoustical properties of the materials you are considering, such as sound absorption and transmission.
2. Determine the required noise level reductions for the space and select materials that will meet those requirements.
3. Consider the environmental impact of the materials and choose options that are sustainable and have low emissions.
4. Take into account the aesthetic design of the space and choose materials that complement the overall look and feel.
5. For a space with multiple functions, such as a conference room that is also used for music performances, consider using different types of materials for different areas of the room to optimise acoustics for each use.
6. Working with an Acoustic consultant for site measurements and recommendations for material specification.
7. Careful attention should be paid to details, such as the proper installation of acoustic materials to ensure optimal performance.
8. Understand the needs of the space. Is it going to be a space for collaboration and communication or for concentration or creativity?
9. Be aware that sound, like water, will find the weakest point through. Therefore, voids in ceilings and ducts need to be addressed.
10. Understand that sound travels through any medium, not just air. Structure-borne sound needs to be addressed separately from airborne sound.
11. Good sound attenuation relies on density and air tightness.
12. Consider allowing background sound into meeting rooms to provide masking and privacy for room-to-room attenuation.
13. Sound absorption needs to be considered alongside sound insulation.
14. Employ a competent professional acoustic consultant. Your Decor Systems consultant will be delighted to assist you with this.

7 Design Tips For the Best Architectural Acoustics

1. Watch out for sound reflections. Straight surfaces reflect sounds back into the central space making sound clarity muddy.
2. Select acoustical treatment carefully. Different materials absorb sound frequencies differently. Make sure your acoustical treatments are absorbing the right sound frequencies.
3. Diminish echoes when necessary. Be aware that sounds travelling within 30 milliseconds of each other are perceived without an echo. Sounds travelling after the 30-millisecond threshold become echoes of the original sound.
4. Don’t let other building systems get in the way. Noise control is important to keep in check as other building systems (like HVAC systems) operate. Keep such clashing noises to a minimum.
5. Keep objects or other obstructions out of the way. Objects that obstruct a sound path can block high-frequency sounds. (Low-frequency sounds can bend around objects.)
6. Get good pattern control. Make sure sound systems for a room get good sound coverage. This will prevent feedback and other sound distortions.
7. For out-of-the-way listening areas, get distributed sound systems. Such “delay-fill” speakers operate with an electronic delay, so the sound matches and is synchronised.

The Importance of Acoustic Consultation in Design Projects

Involving acousticians in the early stages of a project design is crucial to achieving optimal sound performance and avoiding costly and unattractive band-aid solutions after project completion. It's not just about reducing noise; it's about achieving the right acoustic outcome to ensure that the space is fit for its intended purpose.

When architects and acousticians work together from the beginning of a project, they can achieve a sound acoustic outcome and overcome many of the challenges commonly faced in the process. An excellent example of a project that includes careful acoustic consultation is the Surry Hills Community Centre, designed by Francis-Jones Morehen Thorp (FJMT).

The centre, which includes an integrated local library, community centre, and childcare centre, was intended to meet the various needs of the local community. Each space within the centre had very different acoustic requirements, which was a key challenge of the project. To assist with achieving various acoustic qualities for different users within the centre, Decor Systems products were specified by FJMT.

According to an article by Architecture & Design, the high-energy and high-noise levels in both the childcare and community centre zones required acoustic absorption to allow users to engage and interact without excessive noise carrying into the library. To achieve this, the architects used pre-finished, fire-rated, perforated acoustic panels (DecorZen and DecorStyle – by Decor Systems) extensively throughout these spaces, achieving up to 88 per cent of incidental noise absorption. With careful acoustic consultation and the use of Decor Systems products, the Surry Hills Community Centre achieved the desired acoustic outcome, making it a successful project for both the architects and the community.