The Cone of Silence - A Lesson on Sound Masking:

I met with a client recently. They have remodeled their law offices and have some privacy problems. The biggest problem is that conversations conducted in the Board Room can be clearly understood in the adjoining reception area. The rooms are separated by a beautiful glass wall with frameless glass doors. The air gaps around the doors allow sound to travel freely into the reception area for all to hear.

In the course of the conversation, we learned that they had purchased sound masking from the AV Company that had installed the beautiful video conferencing equipment in the Board Room. After listening and searching for equipment, I was not able to find any sound masking.

We found the local expert and learned that to activate the sound masking, you just press a button on the video conference room controls and boom, the speakers in the conference room light up with white noise.
The result of this is that people in the room talk louder so that they can hear each other. “What?! I said turn that down!”

The noise had no effect on the folks sitting in the reception area. They continued to listen to the conversation unimpeded. The Board Room had become The Cone of Silence from Get Smart.

**YouTube: The Cone of Silence**

Lesson 1: Put sound masking where the listener is listening.
Lesson 2: Hire a specialist for sound masking. When it comes to speech privacy, many AV guys don’t know what they don’t know

WSJ on Sound Masking: "those who normally had difficulty paying attention performed better when white noise was added"

Choosing a sound masking system:

When investigating the purchase of a sound masking system, you will be introduced to several different concepts. 

One of the most important characteristics of a quality sound masking system is uniformity.  As people circulate through the workplace, the sound masking should be uniform.  Differences in volume or spectrum will draw attention.  Sound masking should be unobtrusive and blend into the background.

There are several manufacturers in the market today that are using systems with a network backbone.  They are designed like a computer network.  They use a central computer to send information to network nodes that then distribute the signal to sound masking and paging speakers.

The computer allows small groups of speakers to be changed remotely to allow differing volume levels and spectrum adjustments.  The manufacturers of these systems use terms such as “separate and independent configuration” and “on-demand control”.

After initial commissioning, the Facility Manager will have the controls and as changes are made, the system will become less uniform.  With each change, the system will drift away from its intended purpose of masking conversational distractions.

We strongly feel that networked systems provide Complexity without Benefit.

The systems also require electrical connections located through out the treated area to power the network equipment and the speakers.

Centrally controlled low voltage systems require a single electrical connection at an equipment rack.  All wiring from the rack to the speakers is conducted through low voltage plenum rated cable.

Centrally controlled systems provide the ability to deliver highly zoned sound masking and paging with a stable and reliable platform.  Once commissioned, they run trouble free for years.

By all means, compare systems and compare prices.  Then take a look at the organization and ask several key questions:

• Who will install the system?
• Who will commission and tune the system?
• Who will be responsible for service calls?

Many times, large manufacturer’s representatives subcontract installation and service to data cabling firms.  Look for suppliers with in-house personnel and expertise in sound masking and acoustics.

A National Trade Publication has recognized ADI Workplace Acoustics for its expertise:

http://www.systemscontractor.com/article/29030.aspx

We are currently working with several clients that are planning office projects in buildings with raised access floors. 

The use of under-floor HVAC systems provides an efficient delivery method for conditioned air.  One side effect of the system is that they provide very little background sound.  The resulting low background sound allows speech to be clearly understood at significant distances.  This has a highly negative impact on workplace productivity and workplace satisfaction.

We have had terrific success in providing sound masking from below raised access floor systems.  In fact we just walked a new client through a few of our projects last week and they were very impressed.

The advantages for delivering the masking signal from below:

Because the sound transmission loss of the concrete floor tiles is far greater than acoustical ceiling tiles, uniformity of sound from under the floor is much greater than from above.  This leaves users unable to identify speaker locations.

Sound is less affected by location of panel systems and walls than with speakers located above the ceiling.  This allows future reconfigurations to be performed more cost effectively.

Speakers and wire are concealed beneath the floor allowing freedom to use creative ceiling treatments.

ADI Workplace Acoustics has direct experience in the design, installation and commissioning of under-floor sound masking systems.   Our unique design build process allows us to install the system after the floor is installed.  We work around other building trades adapting the speaker layout to other building systems and features.

Acoustics is an often missed element in the design of these facilities.  More efficient HVAC systems, along with fewer barriers and lower panels, lead to poor speech privacy.  The downside of neglecting the acoustics is a lower operational performance for the occupants. 

GSA published a study of 12 recently completed hi-performance buildings:

"For the lower-performing buildings, the study found that occupant satisfaction is undermined by poor acoustics, lighting and maintenance problems.  A low level of ambient noise, a lack of sound masking and a perceived lack of privacy make acoustic quality worse."

https://www2.corenetglobal.org/dotCMS/kcoAsset?assetInode=4820555

A recent study commisioned by the General Services Administration (GSA) looked at the performance of 12 LEED certified buildings.

CoreNet Global's The Leader, January / February 2009:

"For the lower-performing buildings, the study found that occupant satisfaction is undermined by poor acoustics, lighting and maintenance problems.  A low level of ambient noise, a lack of sound masking and a perceived lack of privacy make acoustic quality worse."

https://www2.corenetglobal.org/dotCMS/kcoAsset?assetInode=4820555

Acoustics is an often missed element in the design of these facilities.  More efficient HVAC systems, along with fewer barriers and lower panels, lead to poor speech privacy.  The downside of neglecting the acoustics is a lower operational performance for the occupants.

The solutions are proven and easy to implement.  We just completed a large underfloor sound masking installation.  The results are outstanding.