Sound insulation in meeting boxes
Understanding acoustics in the office
A sound-insulating meeting box reduces the transmission of conversations into the office. How much privacy you actually achieve depends on the model tested, its design and the installation location. Therefore, more than the highest dB number is crucial.
Sound insulation, room acoustics and speech intelligibility: three different tasks
Sound insulation
Walls, glazing, door seals and ventilation routes limit the transmission of sound between the box and the office. The construction as a whole counts for this.
Room acoustics
Absorbing surfaces in the interior reduce reflections. This supports a pleasant conversation situation and a clearer sound during video conferences.
Speech intelligibility
For discretion, it is important whether outsiders can understand words and content. An audible residual noise and an intelligible conversation are not the same thing.
An acoustic sofa or an open work niche can make an area acoustically more pleasant. A closed telephone or meeting box fulfills a different task when it comes to shielding confidential conversations.
What do dB values say for meeting boxes?
Decibels describe a level ratio. A higher insulation value represents a greater reduction using the same measurement method and comparable design. However, a number without a measurement and test basis is not sufficient for a reliable comparison.
The ISO 23351-1 determines the speech level reduction DS,A of a complete furniture system or a cabin in the laboratory. The characteristic value describes the speech sound power radiated to the outside. It is neither the noise level of the fan nor the insulation value of an individual pane of glass.
We explain what the standard measures and how classes A+ to D are classified on our page ISO 23351-1 and acoustic classes for meeting boxes.
What does the statement “32 ± 3 dB” mean?
It states a value with a additional span. This notation is not a separate acoustic class and is not a blanket tolerance specified by ISO 23351-1. The documented test value of the specific design counts for a standard-related classification. The range must not simply be opened up to derive a higher class.
When do conversations outside the box remain confidential?
The box reduces the language transmitted to the outside world. Whether the remaining parts of speech are still understandable also depends on the speaking volume, the distance to the speaker and the background noise in the office. In a very quiet environment, residual noise can be more noticeable than in a busy open space.
Masking helps with classification - it is not a guarantee
Background noise can make leaking speech less noticeable or understandable. However, this masking effect does not mean that every conversation automatically becomes inaudible. A general calculation such as “speaking level minus the insulation value gives the level at the neighboring desk” does not reliably describe the real installation situation.
- Normal telephone calls: In addition to the insulation value, it also evaluates seating comfort, ventilation and the distance to other workstations.
- Confidential conversations: Plans the acoustic performance and the location together. If possible, avoid a listening position directly adjacent to the door.
- Particularly sensitive content: Checks the specific use and the listening situation on site. A class alone is not a guarantee of complete eavesdropping security.
SoSilent model examples: Pay attention to the design and measurement basis
Standard, Plus and various wall configurations can differ even within one line. The following examples reflect the information from the linked product pages; They are not a general classification of an entire product line.
| Model | Product information | What you should pay attention to |
|---|---|---|
| Urban L1³ | Plus and Smart Plus: 32 ± 3 dB | ISO 23351-1 is specified on the product page. Smart Plus complements switchable privacy screens. |
| Space L1, 2nd generation | Standard: 28 ± 3 dB Plus and Smart Plus: 32 ± 3 dB |
The version is crucial. 32 ± 3 dB does not apply across the board to every Space version. |
| Classic L1³ | Standard: 25 ± 3 dB Plus and Smart Plus: 28 ± 3 dB |
For Plus, the selection for a glass front with three solid walls separately states 30 ± 3 dB. Check the selected wall configuration. |
| Smart S1 | 25 ± 3 dB, shown on the product page as NIC value | NIC is not the ISO characteristic value DS,A. Therefore, do not convert the number directly into an ISO acoustic class. |
The current product page, the selected configuration and the associated evidence are decisive. For a comparison according to ISO 23351-1, we look at the documented DS,Avalues of the relevant models.
How to find the right acoustic solution
- Specify usage: Is it about short calls, video conferences, concentrated individual work or sensitive ones Meetings?
- Include environment: How quiet is the office, where are the nearest workplaces and how close are traffic routes?
- Compare configuration: Checks size, wall structure, glazing, seals and ventilation of the specific model.
- View evidence: Compare the same measurement and clarify which version the test report refers to.
Would you like to get your own impression? In the SoSilent showroom in Munich you can experience boxes and discuss your requirements with us. The listening situation in the showroom does not replace checking your own installation location.
Frequently asked questions about the sound insulation of meeting boxes
Are meeting boxes completely soundproof?
No. They reduce sound transmission, but do not eliminate it completely. How much remains audible or understandable outside depends on the speaker, the usage and the environment.
Is 32 dB always better than 28 dB?
For the same measurement and comparable test conditions, the higher value means a greater reduction. Information from different processes, for individual components or for other configurations cannot be compared directly.
Does smart glass automatically improve sound insulation?
Switchable smart glass initially serves as optical privacy protection. The acoustic effect depends on the entire structure. Which sound insulation a Smart Plus version offers must be checked on the specific model.
Can I check the sound insulation with a cell phone app?
A cell phone can give you a first impression of the noise level. Such a measurement does not replace a standardized test report and does not provide a reliable ISO classification of the box.
Which box is right for your office?
We help you bring together usage, acoustic requirements and installation location.
Sources & professional Basics
- ISO 23351-1:2020 - Laboratory procedures for measuring speech level reduction
- Turku University of Applied Sciences - Speech level reduction and test methods
The model examples come from the linked SoSilent product pages.