• Sound Masking: The Basics
    • You can't operate your business in a space that is as quiet as a library or as noisy as a restaurant.
    • You must add a little sound to get the right "signal to sound" ratio.

  • Shhh!
    • You know what happens when you're in a library and you move your chair or tap your pen
    • The same is true in our daily workplaces: we're surrounded by too many sounds within buildings designed to be quiet. That, in a nutshell, is why most offices are so noisy. For the full technical explanation, click on the How It Works tab above.

It's easy to understand why building materials like sound-absorbing wall panels are needed. What's harder to grasp is why adding sound back into an environment gives you control of sound levels overall. By virtue of this control, you improve the functioning acoustics of a space so your employees can speak without having their conversations understood by others (speech privacy); can better concentrate without distraction (greater productivity); and more.


  • How Sound Travels
    • To understand sound masking, it helps to know how sound (a form of energy) travels, and the ABCs of controlling sound.
    • In sum: It's impossible to absorb or block all the sound around us because some will diffract over and around partitions or travel through penetrations in walls or ceilings. Thus, sound that isn't absorbed or blocked must be covered (or masked). And it can't be masked by just any sound — it must be masked by an electronically engineered masking system that meets certain performance criteria, including the preferred criteria for speech privacy.


    • Sounds Like...
      • Sound masking should NOT be noisy or intrusive in any way (unfortunately some of our competitor's systems can be noisy and intrusive).
      • Sound masking does NOT make work areas "louder." It actually makes them more private and comfortable.
      • Sound masking systems are NOT the same as "white noise."


    Masking systems DO produce a sound — and that sound should be barely perceptible. It should be non-directional and harmoniously uniform throughout a given space.

    The random, ambient sound from a masking system gently overrides the sound of both incoming speech and other distracting noises, making the work environment more private and comfortable.

    Most masking systems have a sound source, an amplifier, an equalizer, and speakers to carry the sound. In Lencore's Spectra™ masking systems, a microprocessor-controlled, digital broadband sound (called E-Sound™) is produced. This sound spectrum is custom-tuned and then amplified through individual speakers installed above the dropped ceiling. The Spectra™ speakers are directed upward so that the E-Sound™ filters evenly down to the space below (similarly to the way ambient lighting works), gently raising the background sound level. This method disperses the masking sound without phasing or creating hot or cold spots (see How It Works at the tab above for more details).

  • Who Needs Sound Masking?
    • Almost everyone. If you've ever been interrupted by your co-workers' conversations, been overly aware that other people can hear your conversation or been distracted by ringing telephones, printers and other machines, you're a prime candidate for the benefits of sound masking.
    • Privacy and noise are big issues in open offices. In addition, in healthcare and related service fields, protecting sensitive patient information is not just a top priority, it is the law. The potential for oral disclosure is seen by some to be the most serious of all the risks. For more information about speech privacy in healthcare environments, visit the HIPAA section of this site.
    • The good news: installing a sound masking system is a cost-effective solution.
  • Where Do I Add Sound Masking?
    • Sound masking should be added wherever unwanted sound isn't absorbed or blocked to the satisfaction and comfort of workers in a space...wherever people want to have private conversations, fewer distractions and the ability to concentrate. In short, 99 percent of all workspaces!

      • Medical Facilities
      • Open Offices and Private Offices
      • Pharmacies
      • Financial Institutions and Bank Branches
      • Governmental Agencies
      • Legal Offices and Facilities
      • Call Center Environments
      • Military Facilities
      • Religious Facilities
      • SCIFS
      • Doctor Offices
      • Conference Facilities


      • Lencore's sound masking systems are custom designed to work (with or without acoustic ceiling tiles) in:
        • Open or Closed Office Plans
        • High-Traffic Public or Staff Areas
        • Private Offices
        • New Construction
        • Retrofits


        In open-office floor plans, Lencore's Spectra systems can be tuned to areas as small as 225 sq. ft., or as large as millions of square feet. Lencore's Spectra® systems mask 100 percent of your space (compared with other sound masking systems that only provide limited tuning, and only mask 80 percent of the space).

  • How Sound Masking Works
    • Sound masking works because it changes the 'dynamic range' of sound in an environment
    • Typically, the dynamic range in most environments is large, meaning that there is a great degree of difference between the lowest, or ambient, sound level and the highest levels of sound, when people are actively speaking and working. Offices are perceived as noisy precisely because of this large dynamic range. Here, the higher decibel (dB) sound of normal speech is easily heard in a backdrop of a lower, ambient background sound (dB level).
    • Sound masking works by subtlety raising the ambient background sound level, thereby reducing sound's dynamic range. This effectively "masks" unwanted noise, makes speech unintelligible (creating privacy), and makes the work environment acoustically comfortable.
    • For more on the dynamic range of sound, click on the graph to the right.
    • Complementing Speech with Added Sound
      • The electronic, background sound of a masking system is calibrated at 1-5 dB levels higher than the frequency range of incoming human speech (250 — 6,000 Hertz) from adjacent work areas. Lencore's Spectra®  performance range works from 20 — 20,000 Hz. Thus, by complementing the speech spectrum, conversations cannot be understood.
      • This graph reflects sound pressure levels in decibels, and the logarithmic frequency of typical speech patterns in hertz. The shaded area shows how Lencore Sound Masking systems effectively cover speech levels.
      • To ensure speech privacy, it is essential that the masking system's sound be balanced with the surrounding architecture (walls and partitions) and sound-absorbing furnishings (acoustical panels and ceiling tiles), to consistently produce a comfortable, uniform masking level. ASTM standards do exist for speech privacy, and Lencore has been proven by independent engineers to meet or exceed these standards.
      • Ready to check out sound masking for your facility? Contact Lencore to put a measurably better sound masking system in place!
  • Why Most Workplaces Need Sound Masking
    • The demand for open office environments isn't going away. A report by The International Facility Management Association (IFMA) shows that more than 80 percent of respondents use open-plan systems in their space planning. In addition, many businesses are now allotting less space to employees within open plans, upping the number of people within a room in order to cut overhead. And the trend toward a "team" environment has brought upper management and other executives out of their once private offices and into the mix.
    • Add speaker phones, voicemail and other noisy technology, and the office environment can easily become distracting. With statistics showing that productivity levels in a non-distracting space will rise anywhere from 3 to 20 percent, open-office acoustics are an increasingly critical design issue for architects. Read more about the payoff of speech privacy — both financial and human — here. This isn't to say that the role of the design or facility professional is to create an office that is dead quiet. In very quiet environments, employees, clients and/or customers often won't speak in a normal tone of voice and instead will lower their voices to near-whispers in order not to distract other employees and to avoid being overheard. And the smallest of sounds, from a tapping pen to a clicking keyboard, can easily shatter the fragile concentration of coworkers.
    • As office walls come down and more employees are packed together into the workplace, privacy is affected as well. And industry research indicates that workplaces will continue to become noisier, affecting employee productivity, morale and retention.
    • Architects are increasingly turning to sound masking to override sounds that can't be absorbed or blocked by design elements such as carpeting, acoustical wall panels, ceiling panels or partitions. At the other end of the spectrum, sound masking in quiet environments allows employees to speak at normal conversational levels while maintaining speech privacy.


    • Beyond 'White Noise'
      • Today's sound masking has gone well beyond simple white noise machines. Diffracted sound can be masked with electronically produced sound that's evenly distributed through a space by speakers placed above the ceiling.
      • Sound masking provides a constant, fixed level of unobtrusive background sound that is set to cover speech level and soften other office noises, which then do not appear as distractions to the human ear. To be effective, the masking level should be 3 to 5 decibels louder than incoming speech from adjacent work stations. In an open plan office, the STC (Sound Transmission Class) and NRC (Noise Reduction Coefficient) must be balanced to achieve good speech privacy, while the background sound levels are comfortable and uniformly maintained.
      • Because sound masking is complementary to the speech spectrum and effectively covers speech levels, it reduces the intelligibility of conversations, which makes conversations less distracting to those working nearby.
      • Architects and other design and facility professionals should consider specifying sound masking units that have a step attenuator, a rotating volume control for precise sound-level adjustment volume control and a rotating volume control for paging/music. Units should be able to produce up to 86 dBA to meet the requirements for all ceiling treatments, and have adjustable sound spectrum shaping controls in order to meet the varying spectral requirements of drywall ceilings, various types of ceiling panels, air return grills and openings around lighting fixtures.
      • The sound-generating units must also generate random sequence sounds and not produce a noticeable repetitive pattern or sequence. While effective sound masking systems have traditionally utilized loudspeakers strategically placed above the office ceiling to produce uniform sound masking throughout the workspace, one of the newest and most popular options for architects are sound masking systems that work in tandem with acoustical ceiling panels. These ceiling sound masking systems are superior to other types of centralized or flat-surface speakers alone, giving the architect more options and control over ceiling design and sound masking systems. These systems can be ordered from the acoustic ceiling panel manufacturer and/or the sound masking company.
      • Lencore's Sound Masking Systems create a harmonious atmosphere in which to work that increases people's ability to concentrate, restores speech privacy and allows for greater employee productivity and efficiency.