Page 21 - Modernfold Architectural Products

Acoustical Guide
Operable Partitions

Making A Sound Decision In Operable Partitions

Introduction The industry accepted “measuring stick” for the
Acoustical control is a acoustical performance of operable walls is the
critical factor in virtually Sound Transmission Class (STC) rating. Walls are tested
every type under laboratory conditions with varying frequencies
of environment; (125-4000 cycles per second) to deter mine how much
therefore selec tion of the a sound level decreases when it transmits from one
appropriate oper able side of the wall/partition to the other. This decrease
partition is critical. It’s is called Transmission Loss
important when choosing (TL). For instance, if a
an operable wall system sound measures at 70 dB
to not only consider the space/configuration of your on one side of a parti-
application and how the wall operates, but to also tion, and only 40 dB on
examine the wall’s acoustical performance. The the other, the TL rating
right wall system, in conjunction with complementing would be 30 dB at that
architectural elements, can help produce excellent particular frequency.
acoustical control. Since common sounds
cover a wide range
When selecting a wall system, several questions of frequencies, Sound
need to be asked relative to the room-to-room noise Transmission Class (STC)
reduction. Also to be addressed is the need for the ratings are used to provide a single number rating to
operable partition to provide a sound-absorbing identify the Transmission Loss of a partition as it varies
surface in the rooms formed by the partitions. with frequency. A higher STC rating indicates higher
transmission loss, a desirable attribute of the partition.
What degree of acoustical control will you need?
What does it take to attain it? There are several Modernfold Wall Systems available
Which wall system is better for your needs? with STC ratings to meet most acoustical control
What architectural elements of the project should be applications. For comparison, see how the Modernfold
considered? systems rank with some typical fixed wall systems.
Modernfold developed this guide to answer these and
Typical Sound Pressure Levels
many other questions. If you need more information, Levels in dBA Common Sounds
call us at 800-869-9685 or email info@modernfold.com. Short Exposure can cause
Hearing Loss 140 Jet Take Off
Anticipate Sound Levels 130 Jack Hammer
In order to effectively specify a system to control/ Threshold of Pain 120 Siren
reduce the sound/noise in an environment, you must Thunder
first identify the types and levels of sounds you are Deafening/Threshold of Discomfort 110 Riveting Machine
trying to control. Then, decide on what degree of Hard Rock Band
“acoustical privacy” is necessary in your facility. 100 Boiler Factory
Machine Shop
Very Loud 90 Noisy Plant
What sound levels are likely to be generated by functions Printing Press
using the rooms formed by the operable partitions? Intolerable for Phone Use 80 Kitchen Equipment
How much low frequency energy will there be in the Sports Car Interior
generated sound? What sound levels are permissible on (50mpg)
the “other side” of the operable partition? Loud 70 6-Piece Orchestra
Amplified Speech
Noisy Office
The Typical Sound Pressure Levels chart indicates Speech
the sound-pressure levels of many everyday sounds. 60 Average Factory
Average Radio
Sound levels are expressed in decibels (dB). The Normal Conversation
decibel scale ranges from zero (the threshold of Moderate 50 Average Business Office
audibility or the ability to hear) all the way up to Average Residence
120 dB (the threshold of ear pain) and beyond. The 40 Quiet Radio
chart can be a practical way to help gauge the Faint 30 Private Office
sound levels of your environment. The chart indicates Average Auditorium
sound pressure levels in dBA—sound levels measured 20 Quiet Conversation
Sound Stage (Movie)
on the A scale of a sound level meter. The A scale Very Faint 10 Whisper
minimizes the effect on the measurement of sound at Sound Proof Room
low frequencies. Threshold of Audibility 0 Human Breathing

Please contact your local Modernfold distributor for further assistance, or visit our website at www.modernfold.com. 1