The complete guide to office pod
acoustics & soundproofing

The noise problem that pods are solving

The open-plan office, which became the default workplace design from the 1990s onwards, solved a real problem — it created collaborative, flexible spaces that could accommodate more people at lower cost. But it created a different problem: acoustic chaos. Conversations bleed into adjacent workstations. Phone calls disrupt whole floors. Video calls require people to speak loudly into laptops in rooms full of colleagues trying to concentrate.

The acoustic pod emerged as a response to this problem — a modular, self-contained space that provides the acoustic privacy of a private office without the permanence, cost, or construction disruption of building walls. But as the market grew, so did the marketing noise. Today, terms like "soundproof," "acoustic," and "ISO-rated" are applied inconsistently across hundreds of products at wildly varying performance levels.

This guide gives you the knowledge to cut through that noise — and evaluate acoustic claims objectively, with evidence.

How sound actually works — and why it matters for pods

To understand acoustic pod performance, you need to understand the three fundamental ways that sound travels and can be controlled. Most pod marketing describes only one of them — which is why many products underperform in real-world conditions.

Airborne sound transmission

This is the most obvious type: sound waves travelling through air. When someone speaks inside a pod, their voice creates pressure waves that propagate outward in all directions. Where those waves encounter the pod walls, some energy is reflected back, some is absorbed by the wall material, and some is transmitted through to the other side. The ratio between absorbed/reflected and transmitted energy determines how much of the conversation reaches someone standing outside.

Airborne sound transmission is what ISO 23351-1:2020 primarily measures — how well the pod's walls, door, and glazing prevent speech from being intelligible outside.

Structure-borne sound transmission

Sound can also travel through solid structures — floors, frames, and mechanical connections — rather than through air. This is why you can sometimes hear music through a wall that appears to block airborne sound perfectly: the low-frequency bass is transmitted through the building structure itself. In office pods, structure-borne transmission typically occurs through the frame and through the floor, particularly if the pod sits on the same concrete slab as the surrounding office.

Most pod manufacturers focus exclusively on airborne performance. High-quality pods address structure-borne sound through decoupled construction — where the inner and outer shells of the pod are mechanically isolated from each other so that vibration cannot travel directly between them.

Flanking sound transmission

Flanking occurs when sound bypasses the primary acoustic barrier through indirect paths — through gaps around door frames, through ventilation apertures, through the junction between the pod floor and the building floor. A pod can have excellent wall panels and still perform poorly overall because flanking paths account for a significant proportion of total sound leakage. This is why door seals, ventilation design, and installation quality matter as much as panel specification.

Understanding decibels: what the numbers mean in practice

Acoustic performance is measured in decibels (dB). The decibel scale is logarithmic — not linear — which means the relationship between numbers and perceived loudness is counterintuitive until you understand it.

Key relationships to memorise:

• A 3 dB reduction represents halving of acoustic energy — but is barely perceptible to the human ear
• A 10 dB reduction is perceived as approximately half as loud by most people
• A 20 dB reduction is perceived as approximately one quarter as loud
• A 30 dB reduction reduces perceived loudness to roughly one eighth

This matters because a manufacturer claiming "15 dB noise reduction" sounds impressive but represents less than a doubling of perceived quietness. A claim of "30 dB reduction" — which sounds only twice as good — actually represents a dramatically more substantial reduction in perceived sound. Context is everything.

Why dB claims without context are meaningless

When a manufacturer states "our pod reduces noise by 35 dB," this claim is only meaningful if you know what was measured, at what frequency, in what conditions, and by which method. A 35 dB reduction measured at a single mid-frequency in a laboratory anechoic chamber tells you very little about real-world speech privacy. The ISO 23351-1:2020 standard exists precisely because raw dB claims without methodology are not comparable across manufacturers.

ISO 23351-1:2020 explained — the only credible basis for comparison

ISO 23351-1:2020 is the international standard specifically developed to measure the speech privacy performance of room-in-room acoustic solutions — which is exactly what office pods are. It was introduced because the acoustic standards used for conventional building products (STC, Rw, and others) were not appropriate for measuring pods, which are small, freestanding, and used in varied ambient noise conditions.

What the standard actually measures

ISO 23351-1:2020 does not measure how many decibels a wall panel blocks. It measures speech privacy — specifically, the degree to which a conversation inside the pod is intelligible to a person standing outside in a defined reference condition. This is measured as a Spatial Decay Rate (DL2) and a background noise correction, producing a final privacy class from A to D.

The test is conducted with a calibrated sound source inside the pod playing speech-weighted pink noise, and microphones at defined positions outside. The standard accounts for the ambient noise level of the surrounding space because speech privacy in a noisy environment is better than in a quiet one — a 60 dB conversation is less intelligible against 55 dB background noise than against 30 dB background noise.

The four performance classes

The ambient noise correction — why environment matters

A critical and often overlooked aspect of ISO 23351-1:2020 is that the effective privacy class of a pod changes based on the ambient noise level of its environment. A pod rated Class B in a standard office test condition (65 dB ambient) may effectively provide Class C privacy when placed in a very quiet environment (40 dB ambient), because there is less background noise to mask the conversation leaking from the pod.

This is why Furnify always asks about the ambient noise level of your environment before recommending an acoustic class. In a quiet executive suite, you need a higher-rated pod than you might expect. In a noisy open-plan floor, a Class B pod may be perfectly adequate for sensitive conversations.

Independent testing vs manufacturer claims

The ISO standard requires testing by an accredited acoustic laboratory — an independent body with calibrated equipment and no commercial interest in the outcome. Some manufacturers conduct their own in-house testing and use the ISO methodology without independent verification. These claims may or may not be accurate, but they cannot be compared on equal terms with independently certified results.

Always ask for the name of the test laboratory and the test report reference number. A legitimate independent test report can be verified. An in-house test result cannot.

How pods control sound: the four mechanisms

Effective acoustic performance in an office pod is the result of four distinct mechanisms working in combination. Understanding each helps you evaluate what a specification sheet is actually telling you — and what it might be omitting.

1. Mass — blocking sound with weight

The first law of acoustic physics is simple: heavier materials block more sound. This is known as the mass law, and it states that doubling the mass of a barrier increases sound attenuation by approximately 6 dB. Dense materials — steel, mass-loaded vinyl (MLV), gypsum board — are more effective sound blockers than lightweight materials like single-skin aluminium or thin foam.

This is why the cheapest pods — thin aluminium-framed units with foam acoustic panels — tend to deliver Class C or D performance regardless of the marketing claims. They simply don't have enough mass to block sound effectively. High-performance pods use multi-layer panel systems with dense core materials specifically because mass matters.

2. Absorption — converting sound energy to heat

Sound absorption materials — open-cell foams, mineral wool, acoustic fabric panels — work by converting sound energy into a small amount of heat through friction within the material's internal structure. Absorption reduces the reverberation of sound within the pod interior (preventing the echoey quality that makes conversations harder to understand) and reduces the amount of sound energy available to transmit through the pod walls.

The key measure for absorption is the NRC (Noise Reduction Coefficient) or αw value — a number between 0 and 1 indicating what proportion of incident sound energy is absorbed. A material with an NRC of 0.8 absorbs 80% of sound energy that hits it. For interior pod panels, look for NRC values of 0.7 or above for effective absorption performance.

3. Decoupling — breaking the vibration path

Decoupling is the most sophisticated acoustic mechanism and the one most commonly absent from entry-level pods. When sound waves hit a surface, they cause it to vibrate — and that vibration can be transmitted through structural connections to the other side of the barrier, bypassing the air gap entirely. This is structure-borne sound transmission.

Decoupled wall systems address this by mechanically isolating the inner and outer skins of the pod panel — using rubber mounts, resilient channels, or air gaps with no rigid connections. The result is that vibration from the inner skin cannot travel directly to the outer skin. This is particularly important at low frequencies (below 500 Hz), where mass alone is insufficient.

4. Strategic air gaps and infill

An air gap within a wall construction increases its acoustic performance significantly — because sound has to couple from solid to air and back to solid, losing energy at each interface. The effectiveness of an air gap increases with its width, up to approximately 200mm. Beyond that, diminishing returns apply. High-performance panels fill the air gap with mineral wool, which adds absorption and further decouples the two skins.

Internal acoustics: the side most guides ignore

Most acoustic pod guides focus entirely on how well a pod keeps sound from getting out. Far less attention is paid to how the pod sounds on the inside — which is equally important for usability, and is a frequent source of disappointment with lower-quality products.

Reverberation time (RT60)

Reverberation time — measured as RT60 — is the time it takes for sound to decay by 60 dB after the source stops. In a large, hard-surfaced room (a cathedral, for instance), RT60 can exceed 3 seconds. In a well-designed studio, it might be 0.1–0.2 seconds. In a good office pod, it should be below 0.3 seconds.

When RT60 is too high inside a pod, speech becomes muddy and difficult to understand — words blur into each other as earlier sounds are still decaying when the next sounds arrive. This manifests as the "echoey" quality that users often report in cheaper pods, particularly during video calls where the effect is amplified by microphone processing.

A short RT60 (below 0.3 seconds) is achieved through sufficient interior acoustic absorption — fabric panels, acoustic ceiling tiles, and upholstered surfaces. Hard-surfaced pods (glass walls, hard floors, rigid ceilings) will always have high RT60 regardless of their external acoustic class.

Speech transmission index (STI)

STI measures how well speech is transmitted and understood within a space, on a scale from 0 (unintelligible) to 1 (perfect intelligibility). For a pod used for meetings and calls, an STI above 0.6 (rated "good" to "excellent") is the target. An STI below 0.5 means conversations inside the pod will feel strained and tiring over extended sessions.

A well-specified pod should have both a high external ISO 23351-1:2020 class (good at keeping sound in) and a high interior STI (good at making conversations comfortable inside). These two objectives don't always point in the same direction — some acoustic treatments that improve external blocking can also increase interior reverberation — and the best pod manufacturers engineer for both.

What to ask about internal acoustics

• What is the RT60 at 500 Hz inside the pod? (Target: below 0.3 seconds)
• What is the NRC or αw of the interior acoustic panels?
• Is there acoustic treatment on the ceiling as well as the walls?
• What is the floor surface — hard floor or carpeted? (Hard floors increase internal reverberation significantly)
• Has the interior acoustic performance been measured as part of any published test?

Doors, seals, and glazing: where most acoustic performance is lost

The door is consistently the weakest acoustic element in any pod, and the gap between a well-sealed and a poorly sealed door can be the difference between Class A and Class C performance on an otherwise identical product. This is the element that deserves the most scrutiny when evaluating any pod specification.

Door seal types — in order of performance

• Compression seals (best): A rubber or neoprene gasket that compresses against the frame as the door closes, creating an airtight seal. Compression seals perform well across the full frequency range and maintain their effectiveness as the seal ages. Required for Class A performance.
• Magnetic seals: Similar principle to compression seals but using a magnetic closure system. Common in higher-end pods. Effective and reliable, though seal degradation over time should be monitored.
• Brush seals: A brush or pile of fibres that rests against the frame. Less effective than compression seals — particularly at mid and high frequencies, and at the corners where the brush cannot fully conform to the frame geometry. Adequate for Class C, marginal for Class B.
• No seals / gap-tolerant designs: Some pod designs rely on a labyrinthine entry or a deliberately undersized door gap to reduce sound transmission without a formal seal system. These are entry-level solutions that typically achieve Class C or D at best.

Glazing — acoustic performance of glass

Glass is acoustically challenging because it is hard and relatively thin, which makes it efficient at transmitting sound. However, glazing is a functional requirement for most pods — occupants need natural light and visual connection to the surrounding environment, and glass is also a fire safety consideration in certain configurations.

• Monolithic single-pane glass — the worst-performing option. A 6mm pane provides modest sound reduction. Adequate only for Class C or lower applications.
• Laminated glass with PVB interlayer — significantly better than monolithic glass of the same thickness. The polyvinyl butyral (PVB) interlayer damps vibration at the glass surface and reduces the coincidence dip (a frequency at which glass transmits sound particularly efficiently). Required for Class B performance in glazed panels.
• Double-glazed units (IGU) — two panes with a sealed air gap. The air gap adds an additional acoustic barrier. An IGU with different pane thicknesses (asymmetric configuration) performs better than equal thicknesses because the two panes have different resonant frequencies and don't reinforce each other's weak points.
• Triple-glazed or acoustic-laminated IGU — the highest-performing glazed option. Typically used in Class A pods where the glazing must match the wall panel performance. Heavier and more expensive, but necessary for consistent whole-system performance.

Ventilation and the acoustic trade-off every pod must make

Ventilation is the unavoidable acoustic compromise in every office pod. A completely sealed pod would have the best possible acoustic performance — but would be uninhabitable within minutes as CO₂ levels rose. All pods therefore have ventilation apertures, and those apertures are acoustic weak points.

Why ventilation matters for acoustics

Sound travels efficiently through air — and a ventilation opening, however small, creates a direct air path between the pod interior and the surrounding environment. At the frequency ranges relevant to speech (500 Hz–4 kHz), even a modest gap can allow significant sound transmission, particularly if it is positioned on the same face as the pod door.

How high-quality pods manage the trade-off

• Acoustic baffles: The ventilation path is routed through an internal labyrinth or series of baffles lined with absorptive material. Sound must travel around corners and through absorptive surfaces before reaching the exterior, losing energy at each turn. The air can flow freely; the sound cannot.
• Remote intake/exhaust positioning: Ventilation intake and exhaust grilles are positioned on opposite faces of the pod, and away from the primary occupancy zone, to minimise the direct acoustic path between interior and exterior.
• Active vs passive ventilation: Active systems (fans) can provide adequate air changes with smaller apertures than passive (gravity) systems, which require larger openings to function. Smaller apertures mean better acoustic performance. All performance-class pods should use active ventilation.
• Fan noise management: A fan introduces its own acoustic contribution — mechanical noise inside the pod. Well-designed systems use low-RPM fans on vibration-isolated mounts to minimise this. A good test: is the fan audible when you are sitting inside the pod during a video call?

Air quality and CO₂ — the other ventilation requirement

Beyond acoustics, ventilation must also maintain acceptable air quality. A pod occupied by two people generates approximately 10 litres of CO₂ per minute at rest. Without adequate ventilation, CO₂ levels rise rapidly — research shows that at 1,000 ppm (parts per million), cognitive performance begins to decline; at 2,500 ppm, decision-making quality is significantly impaired.

The UK CIBSE guidance for occupied spaces recommends a minimum of 10 litres per second per person of fresh air supply. For a two-person pod, this means at least 20 litres per second — equivalent to approximately 3–4 air changes per hour for a typical 2.4m × 2.4m pod. Ask your supplier for the ventilation flow rate in litres per second, not just the number of air changes.

Acoustic requirements by environment type

The right acoustic specification depends on where the pod will be installed and what ambient conditions it will face. Here is what changes by environment and what to specify accordingly.

Reading marketing claims: a practical guide

The office pod market is not well-regulated, and acoustic claims vary from rigorously evidenced to meaningless. This table covers the most common claims you will encounter and how to evaluate each one.

Your acoustic specification checklist

Use this checklist when evaluating any office pod against your acoustic requirements. A supplier who cannot answer these questions confidently should be treated with caution — these are not specialist questions. They are the basic acoustic specification a responsible pod supplier should know for every product they sell.

Acoustic glossary: terms you'll encounter