ACOUSTIC CONTROL IN OFFICE SPACES

Baca dalam Bahasa Melayu: Ruangan Pejabat

There are many factors that affect a worker’s efficiency in an office. A major element that is often ignored or overlooked is acoustic comfort. A functional office must address noise issues, especially concerning:

A) IMPULSIVE NOISE

Impulsive noise happens randomly and suddenly, which can severely disrupt focus. It can come from inside the office, like phone calls, chatting colleagues, elevator noises, or ringing phones. It can also come from outside, such as honking cars, nearby construction, or trains.

To reduce this, we must identify the source. If the source is movable, it should be placed far from or shielded from individual workstations. For example, phone calls should be made in a dedicated room built with good sound-insulating materials. This insulation is measured by its STC (Sound Transmission Class) rating.

If the noise source cannot be moved, like traffic or construction, workstations should be relocated to quieter areas. If that isn’t enough, the barrier between the noise and the workers must use materials with a higher STC rating. For instance, offices near train tracks are highly advised to use double-glazed windows.

B) CONVERSATIONAL PRIVACY

Many sensitive matters are discussed in an organization. Management meetings, HR and financial discussions, and confidential client talks need privacy.

Still referring to STC, rooms meant for privacy must use the right building materials and installation methods. Inexperienced contractors can cause losses because high-STC materials are usually expensive but won’t work if installed incorrectly. For example, any unsealed gaps or cracks can cause sound leaks.

Note: Doors are often the culprit for sound leaks. Besides poor STC-rated door panels, leaks often happen through gaps around the door even when closed. This can be fixed by using high-density doors like solid wood or fire doors, fitted with quality acoustic door seals to ensure a tight fit.

C) SPEECH CLARITY

Clear speech is crucial during meetings, briefings, and training. The acoustic values that affect speech clarity the most are Reverberation Time (RT60) and Noise Criterion (NC).

RT60 is the echo decay rate within a room. A high RT60 makes speech unclear and makes a room noisy if many people are talking, like in a discussion, let alone in heated arguments. This causes fatigue and can create a tense atmosphere.

RT60 can be controlled using sound-absorbing finishes like acoustic ceilings and wall panels. An acoustic engineer can determine the required amount of sound absorbers using the Sabine formula or acoustic simulation software. The RT60 value is closely related to the Sound Absorption Coefficient (α) of the room’s materials.

NC is the background noise level in a room. A high NC means a noisy room. If it’s too high, it makes it hard to hear speech, disrupts information delivery, and quickly tires out speakers during long sessions like presentations or training.

NC can be controlled by identifying the noise source and moving it to a hidden spot or enclosing it with silencers. For example, centralized AC blowers should be placed outside meeting rooms so the noise isn’t trapped inside.

Note: NC shouldn’t be too low either. Besides being expensive, a very low NC makes random noises stand out and disrupt focus. This is known as the Sound Masking Effect, where a reasonable level of background noise tends to “soften” impulsive noise.

CONCLUSION

Acoustic control planning should be done early during the office layout stage. Potential noise sources can be listed and the most efficient control methods identified. Site visits during operating hours are crucial before buying or renting an office. Acoustic treatment costs can be saved or avoided entirely with careful site selection.