Acoustic Treatment vs Soundproofing: Differences & Which is Best
Overview
When it comes to improving the acoustics of a room, the terms “acoustic panels” and “soundproofing” are used interchangeably. However, they’re different concepts with unique purposes, applications, mechanisms, and efficiencies.
Acoustic treatment uses acoustic panels to improve the sound quality in a room by controlling echoes and reverberations, while soundproofing uses mass loading, decoupling and damping to prevent sound from entering or exiting a space. The choice between the two depends on whether you aim to enhance sound within a room or isolate it from external noise.
What is the difference between Acoustic Treatment vs Soundproofing?
Acoustic treatment differs from soundproofing in its purpose, mechanism, materials used, applicable surfaces, acoustic metrics, installation and cost.
Purpose: Goals of Acoustic Treatment vs. Soundproofing
The purpose of acoustic treatment is to improve the sound quality within a room, while soundproofing aims to block sound from going in or out of a room regardless of how good it sounds within the space.
Mechanism of Sound Control: Acoustic Treatment vs. Soundproofing
Acoustic treatment and Soundproofing affect sound in different ways.
Acoustic treatment improves sound quality by absorbing, diffusing and reflecting unwanted sound waves to improve sound quality.
Soundproofing blocks sound by adding dense materials, separates elements that transmit sound from one area to another and dissipates sound energy into heat, to stop sound waves from going in or out of rooms.
Materials Used: Acoustic Treatment vs. Soundproofing
Acoustic treatment uses two main types of acoustic panels to improve sound quality in a room:
- Soft Panels: made of fabric, foam, or polyester (PET)
- Hard Panels: made of timber, perforated metal or acoustic plaster
Soft acoustic panels:
Have the highest noise reduction coefficient (NRC), are lightweight, easier to cut and shape, cost effective and aesthetically pleasing. However, soft acoustic panels are not suitable for high moisture environments where they can develop mould and are less durable than hard acoustic panels.
NRC is a single number value ranging from 0 to 1 that describes the average sound absorption of a material. An NRC of 0 indicates the object mostly reflects sound meanwhile and NRC of 1 or higher means the object absorbs most sound.
Examples of soft acoustic panels with their respective NRC rating are:
- Fabric Panels: NRC value of 0.85 -1.0
- Foam Panels: NRC value of 0.6 – 0.8
- Polyester Panels: NRC value of 0.7 – 0.9
Hard acoustic panels tend to have lower NRC ratings than soft acoustic panels but are better at diffusing sound, more durable, suitable for high humidity environments, better for outdoor use, lower maintenance and can be used for both aesthetic and structural components.
Examples of hard acoustic panels with their respective NRC rating are:
- Timber Grooved Panels: NRC 0.5-0.7
- Perforated Metal Panels: NRC 0.6-0.75
- Acoustic Plaster: NRC 0.2-0.5
Soundproofing
Uses different materials depending on the soundproofing method. Understanding the specific soundproofing needs of a given space will help determine the best method. There are three soundproofing methods: mass loading, decoupling and damping.
Mass loading is the practice of adding heavy and dense materials to a surface to block sound waves from going through it. Materials used for soundproofing using mass loading are: mass loaded vinyl, drywall and plywood.
Decoupling involves separating structural elements that sound uses to travel from one area to another. Decoupling is achieved through specialised hardware like sound isolators, joist isolators or resilient channels to break the path sound uses to travel.
Damping refers to dissipating vibrational energy like sound into heat. Damping materials are often viscoelastic materials placed between walls, floors and ceilings. These materials can also be used on acoustic panels.
Applicable Surfaces: Where to use Acoustic Treatment vs. Soundproofing
Spaces where acoustic panels are preferred over soundproofing methods:
- Recording Studios
Acoustic treatment surface: Walls, ceilings
Acoustic panels used: Acoustic foam panels, bass traps, acoustic ceiling tiles
Target RT60: 0.3 – 0.6 seconds
- Home Theaters
Acoustic treatment surface: Walls, ceilings, floors
Acoustic panels used: Fabric-wrapped acoustic panels, carpeting, acoustic ceiling tiles
Target RT60: 0.4 – 0.7 seconds
- Conference Rooms
Acoustic treatment surface: Walls, ceilings
Acoustic panels used: Diffuser panels, wall-mounted acoustic panels, acoustic ceiling tiles
Target RT60: 0.5 – 0.7 seconds
- Classrooms
Acoustic treatment surface: Walls, ceilings
Acoustic panels used: Acoustic ceiling tiles, wall-mounted acoustic panels
Target RT60: 0.4 – 0.6 seconds
- Restaurants
Acoustic treatment surface: Walls, ceilings
Acoustic panels used: Acoustic ceiling clouds, fabric-wrapped panels
Target RT60: 0.7 – 1.2 seconds
Spaces where soundproofing is preferred over acoustic treatment:
- Industrial Factories
Soundproofing surface: Walls, ceilings
Soundproofing methods: Mass-loaded vinyl, cement board
Soundproofing Metric: Sound Transmission Class (STC) 50 – 60
- Apartment Buildings
Soundproofing surface: Shared walls, floors, ceilings
Soundproofing methods: Double-layer drywall with Green Glue, resilient channels
Soundproofing Metric: STC 50 – 60
- Home Offices
Soundproofing surface: Windows, doors, walls
Soundproofing methods: Weather stripping, soundproof drywall
Soundproofing Metric: STC 40 – 50
- Garages
Soundproofing surface: Doors, windows
Soundproofing methods: Sealing air gaps, insulating garage doors
Soundproofing Metric: STC 25 – 35
- Mechanical Rooms
Soundproofing surface: Walls, ceilings, floors
Soundproofing methods: Acoustic sound caulk, mass-loaded vinyl
Soundproofing Metric: STC 45 – 55
Spaces where both soundproofing and acoustic treatment methods are used:
- Music Venues
Surface: Walls, ceilings, floors
Common Methods: Bass traps, diffuser panels, mass-loaded vinyl
Target RT60: 1.2 – 1.8 seconds
Soundproofing Metric: STC 50 – 60
- Hospitals
Surface: Walls, ceilings
Common Methods: Acoustic ceiling tiles, double-layer drywall
Target RT60: 0.6 – 1.0 seconds
Soundproofing Metric: STC 40 – 50
- Hotels
Surface: Walls, ceilings, floors
Common Methods: Carpeting, soundproof drywall, acoustic ceiling clouds
Target RT60: 0.8 – 1.2 seconds
Soundproofing Metric: STC 45 – 55
- Churches
Surface: Walls, ceilings
Common Methods: Fabric-wrapped panels, resilient channels
Target RT60: 1.5 – 2.0 seconds
- Gyms and Fitness Centers
Surface: Walls, ceilings, floors
Common Methods: Rubber flooring, acoustic foam panels, sealing air gaps
Target RT60: 1.0 – 1.5 seconds
Soundproofing Metric: STC 40 – 50
Efficiency Metrics: Acoustic Treatment vs. Soundproofing
Acoustic treatment and soundproofing have different metrics to measure their effectiveness or desired outcome.
Acoustic treatment uses the following metrics to quantify and assess the sound quality of a given space:
- Reverberation Time (RT60): the most important parameter in acoustics and is used both in acoustic treatment and soundproofing methods. It measures how long (in seconds) it takes for sound to decay to 60 decibels in a given space. Different rooms have different ideal RT60 values depending on the purpose of the room.
Ideal RT60 values are:
- Home Theater: 0.3 – 0.6 seconds
- Recording Studio: 0.3 – 0.6 seconds
- Classroom: 0.3 – 0.6 seconds
- Office: 0.5 – 1.0 seconds
- Conference Room: 0.5 – 0.7 seconds
- Concert Hall: 1 – 2 seconds
- Church or Worship Space: 1.5 – 2.5 seconds
- Restaurant: 0.8 – 1.2 seconds
- Hospital Wards: 0.3 – 0.7 seconds
- Gymnasium: 0.4 – 0.6 seconds
- Auditorium: 1.5 – 2.5 seconds
- Early Decay Time (EDT): measures how long (in seconds) it takes for sound to decay the first 10 decibels in a given space.
- Clarity Index (C50 or C80): helps assess how clear or distinct speech or music is in a given space. Technically it’s the ratio of energy between early reflections (occurring within 50ms or 80ms) and later arriving reverberant sound. It measures the clearness and definition of the sound source
- Sound Pressure Level (SPL): quantifies the amplitude of sound waves in decibels (dB) to determine if a room has spots of excessive loudness or dead spots where sound waves cancel each other.
- Frequency Response: measures how a room treats different frequencies. Ideally an acoustically treated room will have a balanced frequency response that doesn’t overemphasise or suppress any particular range of frequencies.
- Speech Transmission Index (STI) or Speech Intelligibility Index (SII): STI or SSI aims to quantify how well a listener would understand spoken words in a given space. It considered the clarity and quality of the speech itself as well as background noise and reverberation that might affect it from being understood. It ranges from 0 to 1 with higher values indicating more understandable speech.
- Subjective assessment: acoustic engineers usually use subjective evaluations to give final recommendations.
Soundproofing methods use the following metrics to quantify and assess the sound quality of a given space:
- Sound transmission class (STC): quantifies the effectiveness of a material or construction element in reducing airborne sound transmission. STC is the most important metric for evaluating the soundproofing capabilities of walls, ceilings, floors, doors and windows.
Higher STC rating indicates better soundproofing performance. For example, a wall rated at STC 30 will allow most sentences to be understood easily from one side to the other, while a wall with an STC rating of 60 should block loud conversational or ambient noise.
Common STC values are:
- Bedrooms: STC 45-50 – minimise conversation and TV noise from adjacent spaces.
- Bathrooms: STC 40-45 – Sufficient to muffle most household noises.
- Open Plan Offices: STC 35-40 – Adequate for a general buzz but not for speech privacy.
- Closed Offices: STC 45-50 – Designed for confidentiality and minimal disturbance.
- Conference Rooms: STC 50-55 – Higher STC values are necessary for confidential conversations.
- Classrooms: STC 45-50 – Necessary for good speech intelligibility and concentration.
- Lecture Halls: STC 50-55 – To ensure audibility even in the back rows and to minimise disturbance from adjacent spaces.
- Healthcare Patient Rooms: STC 40-45 – To provide a quiet environment for rest.
- Consultation Rooms: STC 45-50 – For patient confidentiality.
- Theatres: STC 60-65 – To completely isolate from external noise and ensure a pure auditory experience.
- Recording Studios: STC 55-65 – These values help to prevent sound leakage, maintaining recording integrity.
- Factories: STC 40-45 – To reduce machinery noise spreading to office spaces or the exterior.
- Airports, Train Stations: STC 40-50 – To minimise engine noise, announcements, and people.
- Noise Criterion (NC) or Noise Rating (NR): a measure of the noise level within a space. Lower numbers are quieter.
- Impact Insulation Class (IIC): evaluates the sound insulation of impact noises such as footsteps or dropped objects. Higher IIC numbers indicate better impact sound insulation.
- Field Sound Transmission Class (FSTC): measures sound reduction on site and is a way of evaluating the effectiveness of installed soundproofing installations. Higher numbers mean better soundproofing
- Sound Reduction Index (SRI): similar to STC but mostly used in Europe. Measures the reduction of sound passing through a material at various frequencies in decibels (dB).
Installation Differences: Acoustic Treatment vs. Soundproofing
Acoustic panels are usually installed after a room has been built and are typically installed on walls, ceilings or even as free-standing partitions.
Acoustic panels are generally quick and easy to install and can be done by professionals or a DIY project. Acoustic wall panels are usually sticked or attached to walls, acoustic ceiling tiles are usually just placed on a suspended ceiling grid and portable free standing partitions are usually just rolled into a space when required.
Soundproofing methods are included into building structures during construction such as walls, floors and ceilings. Soundproofing alterations after a building is built makes alterations expensive and labour intensive.
Soundproofing may also include door and windsor modifications. Strict building code regulations apply for soundproofing methods which are only executed by professionals.
Budget Considerations: Costs of Acoustic Treatment vs. Soundproofing
Costs associated with acoustic treatments and soundproofing methods depend on various factors including materials, labour and the size and complexity of the project at hand.
Generally, acoustic treatments are more affordable than soundproofing solutions as materials are less expensive, installation is straightforward and coverage areas are smaller (soundproofing is applied to a full wall while acoustic panels can be installed on a fraction of the surface of the wall).
Budget considerations for acoustic treatment with acoustic panels:
- Material Costs: materials for acoustic panels are less expensive.
- Labour Costs: Installation is typically straightforward and doesn’t require specialised labour. Many acoustic panels are DIY-friendly.
- Area Coverage: Generally there is no need to cover every surface of a space, which reduces material and labour costs.
- Availability: basic acoustic panels are affordable. However custom or specialty panels and designs where aesthetics are important can increase the price
- Maintenance: in indoor spaces with proper humidity control, low maintenance is needed, keeping long-term costs low. However outdoor applications or panels installed in high traffic areas may be damaged and require replacement or frequent cleaning and inspection to avoid mould.
Budget considerations for soundproofing
- Material Costs: Soundproofing materials are often more expensive and cost more to transport and work with (heavy and dense materials)
- Labour Costs: Installation is labour-intensive, requiring skilled tradespeople. This can be a significant portion of the overall cost, however it’s usually included in the building cost of a building.
- Area Coverage: often requires work on the full surface of walls, ceilings, floors, and even HVAC systems, increasing the amount of material and labour required to soundproof a space when compared to just acoustically treating it
- Customization: custom soundproofing solutions, like floating floors or room-within-a-room constructions, are usually expensive compared to acoustic panel installations for similar areas.
- Maintenance: Depending on the system, there may be higher long-term maintenance costs, but generally once the soundproofing solution is built it has a similar lifetime than the building.