For years, designing an open-plan office was often a tug-of-war between aesthetics and functionality. We wanted collaborative spaces, but we ended up with environments where you could hear the telephone argument a colleague was having with his wife from the other side of the office. While older standards focused primarily on noise levels, the introduction of ISO 22955:2021 (Acoustic quality of open-plan offices) has shifted the focus to where it belongs: the user experience and speech privacy.

What is ISO 22955:2021?

This standard provides a sophisticated framework for managing acoustics based on the specific activity occurring in a space. Rather than a one size fits all decibel limit, it acknowledges that a call centre has different acoustic requirements than a creative hub or a focused workstation zone.

Key Passages and Principles

One of the most significant shifts in the standard is the emphasis on discreet speech. It highlights that the most distracting element in an office isn’t loud noise, but intelligible noise. When you can understand the words of a nearby conversation, your brain’s pre-attentive processing is triggered, making it nearly impossible to focus on complex tasks.

Among other things, the standard addresses:

• The Decoupling of Distances: It introduces metrics for “distraction distance” (the distance at which speech becomes unintelligible).
• Background Noise Levels: It suggests that a controlled, steady level of ambient sound is actually beneficial for masking intrusive speech.
• Acoustic Zoning: It recommends grouping similar activities together to ensure that high-intensity verbal areas don’t bleed into quiet zones.

The role of sound masking

While ISO 22955:2021 discusses physical barriers and absorption, it also creates a clear path for the benefits of sound masking. Passage 6.4 of the standard touches on the importance of the signal-to-noise ratio. If a room is too quiet, the signal (your neighbour’s voice) is too sharp.

By introducing a Soundmask system, you are essentially filling the acoustic gaps in the room. This reduces the distraction distance and ensures that the ambient sound level meets the standard’s recommendations for a comfortable, non-intrusive workspace. Unlike white noise, a tuned Soundmask system follows the specific frequency curves required to render human speech unintelligible without being noticed by the occupants.

Conclusion

ISO 22955:2021 is a welcome evolution in international office design. It confirms what we have championed for years: that a truly productive office isn’t a silent one, but one where sound is managed intelligently. By integrating sound masking with the principles of this standard, businesses can finally achieve the collaborative benefits of open-plan layouts without sacrificing the focus of their employees.