

S ound not only affects our mood and emotions, it can affect what we think and, indeed, our ability to hear ourselves think.

In the workplace, bad acoustical design can increase stress and reduce productivity. At any given time, a cubicle worker may be overhearing one or more phone conversations, water cooler chats, impromptu meetings, bull sessions, and even co-workers muttering at their computers. These distractions often drown out our own thoughts, turning us into involuntary eavesdroppers.

This article will examine the problem of conversational distraction in more detail and explore ways to reduce or mask office noise. A companion article, "Learning to Tune Out Distraction," will focus on ways to reduce stress and improve our ability to concentrate in a noisy environment.



The Cubicle Environment

"Reviled by workers, demonized by designers, disowned by its very creator, it still claims the largest share of office furniture sales — $3 billion or so a year — and has outlived every 'office of the future' meant to replace it. It is the Fidel Castro of office furniture." [1]

The cubicle was intended to provide privacy, encourage communication and offer vertical space for pinning up documents. Unfortunately, its developer, Robert Propst, did not foresee that economics would lead to what he later called the "monolithic insanity" of the cubicle farm, as employers tried to warehouse worker bees as cheaply as possible [1] .

The promise of increased communication is very attractive. However, several studies have failed to support the supposed benefits of open-plan offices and cubicle systems. Instead, users report interruptions, lack of privacy, and frequent distractions [2] .

"Would it be smart to save $5,000 over the course of a year by putting a highly valued, expensive employee in open space, where that person won't do the best possible job? We don't think so."

— Nick MacPhee, Microsoft [3]

While over 70% of office workers say that a reduction in noise would increase their productivity, only 19% of executives surveyed were aware of a noise problem [4] . The cost savings from more efficient packing of the workforce may be short-sighted in view of the impact of increased noise on productivity, stress and employee turnover.



Stress and Distraction

"A buzzer sounded in George's head. His thoughts fled in panic, like bandits from a burglar alarm."

— Kurt Vonnegut, Jr., "Harrison Bergeron" [18]

Noise is one of the most frequently reported problems in the modern workplace [2] . Clearly many employees are unhappy with the cubicle environment and its effect on their ability to concentrate. For example:

"I made simple programming mistakes that cost hours of debugging." "Inspirations would disappear into thin air and never return." "When you have to keep twenty things in your head at one time, you can't afford to be overhearing your co-worker's phone calls about his explosive diarrhea problem."

Numerous studies have confirmed that noise has a significant negative impact on the ability to concentrate. Noise exposure can also have after-effects such as a build-up of stress and a reduced tolerance for frustration [5] .



Individual Differences in Noise Sensitivity

While over half of office workers surveyed report feeling disturbed by frequent conversations and other distractions [2] , some people are more disturbed by such interruptions than others. Introverts and participants who rate themselves as 'noise-sensitive' do more poorly than other subjects when tested in the presence of noise [6] . Extroverts often prefer to study in the presence of noise or music, while introverts prefer quiet. However, under many test conditions, both introverts and extroverts are adversely affected by noise.

Hyperacousis is an extreme sensitivity to sound, often associated with tinnitus (ringing in the ears). In one study, 43% of classical musicians reported symptoms of hyperacousis [21] . People with hyperacousis are often tempted to plug their ears to minimize their sound exposure, but this can actually increase their sensitivity [20] .Some people with Asperger Syndrome are also extremely sensitive to sounds and may have trouble blocking out distractions [19] .



Task Complexity

"We believe strongly that the nature of a person's work should dictate decisions about space — in other words, form should follow function. We've found that software developers do their best work in private, quiet spaces — hence the private offices in Redmond. But our sales and marketing people work in a mixture of private and open spaces..."

— Nick MacPhee, Microsoft [3]

Certain types of tasks are more suited to open spaces than others. Simple, mindless tasks such as web-surfing can be performed in almost any environment (and if the workplace becomes too chaotic, those can easily become the default activities). As sound levels increase, the complexity of the tasks one can perform generally decreases [7] .

Complex tasks such as programming, engineering, writing and design work often involve the psychological state of flow. This is a fragile state of concentration that can take fifteen minutes or more to engage and is easily broken by distractions such as irrelevant speech [8] .

Social, collaborative tasks call for a social, collaborative environment. But if some workers are being social while others are trying to concentrate, conflict is inevitable. While it's important to promote the sharing of ideas, people are not always mindful of how far their voices carry, and cubicle walls do not distinguish between relevant and irrelevant communication.



Types of Unwanted Sound

"Corporate accounts payable, Nina speaking. Just a moment.

Corporate accounts payable, Nina speaking. Just a moment.

Corporate accounts payable, Nina speaking. Just a moment..."

— "Office Space" (movie)

In general, people are more annoyed and distracted by sounds they consider unnecessary (idle chit-chat) than by sounds they view as inevitable (keyboard noise, etc.). Also, unexpected sounds and noises generated by others tend to be more annoying than sounds that are predictable and under the individual's control. In fact, noise can be thought of as "any unwanted sound created by another person."

Music has been shown to have mixed effects on concentration. In a noisy cafeteria setting, listening to music on earphones reduced the amount of distraction [9] . However, this is a very subjective area, and a great deal depends on the user's personality and ability to control the volume and type of music.

Speech is considered the most annoying and distracting type of office noise. Studies on the 'Irrelevant Speech Effect' have repeatedly shown that participants perform worse on various tasks even when told to ignore the irrelevant speech.

One study found that irrelevant speech could reduce test performance by about two-thirds [10] . Irrelevant speech is particularly disruptive of processes involving memory, such as reasoning, mental arithmetic and problem solving. Intelligible speech is more disruptive than unintelligible or nonsense speech [11] .

Unfortunately, just as people seem drawn to watch a television set anywhere in their vicinity, they also find themselves attending to irrelevant speech against their will. The result is frustration and a loss of productivity.



Coping with Conversational Distraction

There are several ways of achieving absolute silence: for example, severing the eighth cranial nerve, immersing oneself in total vacuum, or setting the thermostat to 0º Kelvin. As these are not well-suited to the workplace, we will focus on other ways of addressing the problem.



Minimizing It at the Source

Employees can fight back against workplace noise using a little-known technique called "passive aggression." For example, if fellow employees habitually review their voice mail on speaker-phones, Scott Adams suggests leaving embarrassing, suggestive messages for the whole office to hear [12] .

In the long run, though, it may be more effective to deal with the problem directly. When you ask politely for what you want, most people will try to cooperate.

If the problem continues, you can help remind them by posting a sign such as the following:

Quiet Please! — Work in Progress

Help Create a Culture of Acoustic Courtesy:

Extended conversations should take place in an office or conference room.

Limit unnecessary chit-chat or take it someplace where you won't disturb others.

Don't use a speaker-phone in a cubicle.

Unfortunately, human nature and open-plan workspaces being what they are, conversational distractions will continue to occur from time to time. If only there were a simple technological solution...



Noise Cancellation

Noise-canceling headphones attempt to fight sound with sound, canceling unwanted sounds with waveforms that are "equal and opposite." This technology works well for predictable, low-frequency sounds such as airplane engine noise. Unfortunately, it tends to be less useful at voice frequencies; in practice, the effect is often more like a tone control adjustment, not a miraculous deletion of the offending voice.



Noise Masking

If we can't stop noise at the source, absorb it with acoustical barriers (such as office walls), or cancel it with anti-noise, we can still mask it with other, less distracting sounds. While this is a sub-optimal solution, we're better off masking irrelevant speech than suffering the stress and distraction of pretending to ignore it.

Masking relies upon the fact that audio signals are most easily obscured by sounds which are similar in frequency and nearby in time. The popular MP3 audio format relies upon acoustic masking to increase its compression efficiency.

A number of companies sell sound masking systems. These are typically installed in the plenum space above the ceiling to increase the ambient background sound level, in order to reduce the intelligibility of intrusive speech. The sound is filtered to resemble that of the air conditioning system [13] . Independent studies of sound masking systems have reported productivity gains of 8 to 38%, stress reduction of up to 27%, and job satisfaction increases of 125 to 174% [14] .

However, there can be a conflict between the need for high frequencies, which are most effective at masking speech due to their resemblance to the spectrum of consonants, and the possibility that the high frequency masking sound itself could become annoying. In addition, employees often have no way to turn down the volume when the masking is not needed.

Many office workers adapt to unwanted conversation by playing music through personal stereos or work computers. One experiment with 256 company employees showed substantial increases in performance for the group which listened to music through headphones [15] .

While the use of personal stereo systems provides a sense of control, many types of music, especially music with lyrics, can be almost as distracting as the unwanted speech. Also, if speakers are used, co-workers may not share the employee's musical taste.

In addition, if the spectrum of the music is not optimized for speech masking, the listener may be tempted to turn up the headphone volume too loud, resulting in hearing fatigue or even hearing damage, such as tinnitus (ringing of the ears) or actual hearing loss. Strongly rhythmic popular music, in particular, may tempt users to turn up the volume to unhealthy levels. As with carpal tunnel syndrome, people generally assume they are immune to the effects of repetitive acoustic stress until the problem happens to them. [23]



Desired System Characteristics

"Overall, it appears that sound masking can contribute to acoustic satisfaction in open-plan offices. However, both their level and spectral properties should be selected so that the overall acoustic environment is neither too loud nor too hissy, while still masking annoying speech sounds." [2]

The ideal system would be:

Effective at masking speech Broadband, with speech-like spectral content Spatially diffuse, so it masks speech coming from any direction

Not distracting No intelligible speech or lyrics No catchy melodies

Not annoying Not too loud Not too high-frequency Not obviously repetitive

Relaxing and/or energizing

Suitable for headphones or speakers

User-adjustable

Minimizing Distractibility

Often, our emotional response to intrusive noise can be as distracting and stressful as the noise itself. In addition to masking unwanted sounds, we might also consider ways of improving our concentration, reducing our distractibility and becoming aware of our emotional reactions to office noise. These techniques are discussed in a companion article, "Learning to Tune Out Distraction" [16] .

Noise Masking Software

ChatterBlocker™ is a personal computer application that offers a variety of masking sounds, which can be played individually or in any combination. Users can select one or more sounds from each of three categories: sound effects, music, and chatter voices.

The sound effects consist primarily of nature sounds. Sounds of wind and water are effective at masking speech, but are also pleasant to listen to. Just as unwanted noise can deplete a person's energy, pleasant sounds can conserve energy, reducing stress and burnout. Wind, water and bird sounds can calm, refresh and rejuvenate.

The chatter voices are background "walla" or "cafeteria noise" recordings consisting of many simultaneous conversations. The effect is like being in a large conference room where many people talking at once but none of the individual voices are intelligible.

The recordings have been spatialized so that the voices seems to come from all directions, especially on headphones but also through stereo speakers. This helps mask speech coming from any direction.

Since nothing matches the spectral content of speech quite like speech, the chatter voices are quite effective at masking the intelligibility of unwanted conversations. However, the sound of distant chatter, while less distracting than intelligible speech, can still be somewhat annoying if played by itself. Therefore, ChatterBlocker allows users to mix in various amounts of music and/or nature sounds. The chatter voices can be turned off or set to a low level chatter except when needed to mask particularly intrusive speech.

The music category is intended to add variety. Any of the tracks in the music category can be played separately or together. All tracks are asynchronous; since each track has a different length, the tracks will line up differently each time they repeat, to prevent obvious repetitions. This is especially important if the user is listening to the same sounds all day. The result is seeming random yet familiar, like the irregular repetition of wind chimes. Obvious or 'catchy' melodies, which might annoy users or co-workers over time, are avoided. Users can add their own music if desired.

The volume of each of the three categories can be adjusted independently. Thus, users can solve various office noise problems as follows:

Problem: Occasional quiet conversation Intermittent medium-loud conversation Constant loud conversation Solution: Quiet nature sounds Nature sounds, music, and

low level chatter voices Nature sounds, music, and medium chatter voices

ChatterBlocker also offers a number of guided meditation tracks intended to increase concentration, reduce distractibility and minimize the stress response to office noise. In addition, periodic bell sounds may be used as reminders to take a deep breath, relax the body and focus the mind.



Conclusion

Irrelevant speech is a significant problem in the workplace, and not just during company meetings. The best ways to address the problem are:

Minimize it at the source (by limiting unnecessary conversations in open office areas), and Absorb the sound architecturally (e.g., with hard-walled offices).

Often, however, neither of these solutions is feasible. In this case, the best alternatives are to obscure the unwanted speech with pleasant masking sounds and to minimize our distractibility. This article summarizes characteristics of the ideal sound masking system and discusses software for reducing noise intelligibility using a mix of nature sounds, music, and distant simultaneous voices.



References

[1] J. Schlosser, "Cubicles: The great mistake," Fortune Magazine, 2006 March 22.

[2] M. Navai, J. Veitch, "Acoustic Satisfaction in Open-Plan Offices: Review and Recommendations," Research Report, National Research Council Canada, Institute for Research in Construction, IRC-RR-151, 2003 July 17.

[3] J. Vischer, "Will This Open Space Work?" Harvard Business Review, 1999 May-June.

[4] R. Young, "A sound business plan (Designing better acoustics for today's open offices)," Building Design & Construction, 40(6): 84, 1999.

[5] L. Percival and M. Loeb, "Influence of noise characteristics on behavioral aftereffects," Human Factors, 22. 341-352, 1980.

[6] W. Ellermeier and K. Zimmer, "Individual differences in susceptibility to the "irrelevant speech effect," Journal of the Acoustical Society of America, 102: 2191-2198, 1997.

[7] A. Kiellberg, U. Landstrom, et al, "The effects of non-physical noise characteristics, ongoing task and noise sensitivity on annoyance and distraction due to noise at work," Journal of Environmental Psychology, 16: 123-126, 1996.

[8] T. DeMarco and T. Lister, Peopleware: Productive projects and Teams. Dorset House Publishing Co., Inc., NY, 1999, 1987.

[9] K. Kallinen, "The effects of background music on using a pocket computer in a cafeteria: immersion, emotional responses, and social richness of medium," Conference on Human Factors in Computing Systems, Vienna, Austria, pp. 1227-1230, 2004.

[10] S. Banbury and D. Berry, "Disruption of office-related tasks by speech and office noise," British Journal of Psychology, 89, 499-517, 1998.

[11] D. Jones, "Progress and prospects in the study of performance in noise," in Noise as a Public Health Problem, Vol. 4, B. Berglund and T. Lindvall, eds., Swedish Council for Building Research, Stockholm, 1990.

[12] S. Adams, "Dilbert Newsletter #17," http://www.dilbert.com/comics/dilbert/dnrc/html/newsletter17.html, 1997.

[13] J. March, S. Stahovic, Open Plan Office Acoustical Privacy, Product Crafters, 1984.

[14] E. Lewis, P. Lemieux, D. Sykes, T. Horrall, "Sound Masking in the Office: Reducing noise distractions to increase worker productivity," Herman Miller, Inc., 2003.

[15] G. Oldham, A. Cummings, et al, "Listen while you work? Quasi-experimental relations between personal-stereo headset use and employee work responses," Journal of Applied Psychology, 80: 547-565, 1995.

[16] E. Vickers, "Learning to Tune Out Distraction," http://chatterblocker.com/whitepapers/tune_out_distractions.html, 2006.

[17] E. Vickers, "Automatic Long-term Loudness and Dynamics Matching," Proceedings of the AES 111th Convention, New York, 2001.

[18] K. Vonnegut, Jr., "Harrison Bergeron," Welcome to the Monkey House: A Collection of Short Works, New York: Delacorte/Seymour Lawrence, 1968.

[19]. Wikipedia, "Asperger Syndrome," http://en.wikipedia.org/wiki/Asperger%27s.

[20] J. Hazell and J. Sheldrake, "Decreased Sound Tolerance: Hypersensitivity of Hearing (Hyperacusis, misophonia, phonophobia)," The Tinnitus and Hyperacusis Centre, London UK, http://www.tinnitus.org/home/frame/THC1.htm.

[21] H. Laitinen, "Factors Affecting the Use of Hearing Protectors Among Classical Music Players," Noise & Health, 7(26):21-29, 2005.

[22] Oommen, Vinesh G. and Knowles, Mike and Zhao, Isabella, "Should Health Service Managers Embrace Open Plan Work Environments? A Review," Asia Pacific Journal of Health Management, 3(2), pp. 37-43, 2008 , article: http://www.lapa.co.nz/assets/NewsAttachments/openplanofficeszengine.pdf , summary: http://www.news.qut.edu.au/cgi-bin/WebObjects/News.woa/wa/goNewsPage?newsEventID=23175

[23] E. Vickers, "The Loudness War: Background, Speculation and Recommendations" (additional material), http://www.sfxmachine.com/docs/loudnesswar/index.html .





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