Guide To Office Sound Management
When you design and furnish your office, it’s important to take Sound Management into account. Much of the discontent with open office plans and the cubicle workstation is due to sound problems – the lack of privacy and the difficulty to concentrate. It’s important to note that working in a silent office can also disturb concentration because every small sound is amplified.
The following is some basic terminology and concepts to keep in mind so that you can make an informed decision when you do your furniture shopping.
Anywhere that smoke can travel, sound can travel because sound is simply energy that is carried by the air.
Direct – Sound that travels directly from the messenger to the receiver.
Reflected – Sound that bounces off a surface, and then continues its path.
Refracted – Sound that bends around a surface (like a partition).
Block – Place walls or barriers to stop the sound from passing (for direct sound paths).
Absorb – Materials that absorb the sound instead of reflecting it back out (for reflected sound paths).
Mask – Cover up sound with another, consistent sound that is more pleasant or less intelligible.
dB (decibel) – Unit of sound volume. 20 dB is quiet and 100 dB is loud.
Hz (Hertz) – unit of sound frequency (pitch). The high end of a piano has a higher Hz than the low end).
CPS (Hertz Cycles Per Second) – Measure of sound frequency.
Sound Management Measurements:
STC (Sound Transmission Class) – A measure of the volume that a material will block from passing through. A panel with a STC of 21 will stop sound at 21 decibels from going through.
NRC (Noise Reduction Coefficient) – A measure of how much a certain material absorbs sound. An NRC of 70 means the material absorbs 70% of the sound and reflects 30%.
Articulate Speech Frequencies – the frequencies at which sound is intelligible (that of the human speech). Approximately 1,000 through 3,000 Hz.
This is important to take note of because intelligible sound is a lot more distracting than muffled noise, because our brains recognize that it is intelligible and try to decipher it. A material that has an NRC of 70 at 200 Hz won’t do the same job as a material with the same NRC but at 2,000 Hz.
NIC (Noise Isolation Class) – The interaction between STC and NRC. A furniture system with an NIC of 21 will block up to 21 dB of sound.
Different sound management products and office furniture systems will have advantages and disadvantages. No one product can address all sound issues so it’s an important to have an integrated plan.