Video Meetings Fatigue You: The 4 Key Acoustic Considerations
Introduction
Home offices and video meetings have become the new norm for many professionals. In fact, nearly a third of all Australian workers have been working from home during periods in 2020 [1, 2]. Interestingly, it has also been found that these workers are wanting to work from home in the future for an average of 2 days a week [3]. Another study even states that Australians would stay with their employer for longer or even take a pay cut to work from home [4].
It is expected that the benefits of work from home and evident preference have influenced how we will be doing business in the future. International companies such as Twitter have announced that their employees will be allowed to work from home ‘forever’ [5]. With another survey finding that 67% of enterprises will keep work from home in place [6]. In Australia, 75% of workers believe that their employers will facilitate future work from home plans [7].
Working from home though does not come without its challenges. With the greatest disadvantages being self-reported as isolation, distractions and work-life balance [8]. Another impact can be a negative impact on relationships with co-workers and knowledge transfer [9].
– An Acoustics Glossary that addresses some of the terms we will discuss can be found at the base of this article!
Zoom Fatigue
Perhaps one of the greatest challenges of work from home is the present-day phenomenon of “Zoom Fatigue”. There is no denying that video meetings and conferences are exhausting. Zoom Fatigue or other video meeting software associated fatigue has been described in Psychology Today as the “tiredness, anxiety or worry resulting from overusing these platforms” [10].
Irrespective of any potential technical issues associated with video meetings, the causes are numerous; Millisecond delays in verbal response negatively influencing our interpersonal perceptions leading to unnatural gaps in conversation and a lack of natural rhythm [11]. Eye contact and ‘gaze awareness’: which relates to a human’s ability to convey emotion and intention during face-to-face meetings is also significantly impaired during video meetings [12].
The additional screen time during work from home can also increase fatigue and the risk of ‘Computer Vision Syndrome’, which includes symptoms of; decreased productivity, eye strain, headaches, blurred vision, dry eyes and neck & shoulder pain [13, 14].
What does this have to do with Acoustics?
The symptoms of Zoom Fatigue are comparable to the symptoms of poor acoustics. We know that poor acoustics can lead to fatigue and lack of productivity as discussed in Acoustics for Interior Designers. The concern here is that; if video meetings are creating fatigue, then video meetings plus poor acoustics will compound the negative associated symptoms.
Video meetings are susceptible to poor acoustics due to the home environment being too noisy, too reverberant and the additional element of an audio system (microphone & speaker) providing another acoustical factor that needs to be considered. Even the ‘echo’ that you sometimes hear at the other end of your video call is often related to the acoustics.
Working from home needs to change our acoustical expectations to match what we expect from any workplace. It is important to get it right. It could mean leaving a good impression on a client, communicating effectively between colleagues or minimising your own fatigue and increasing productivity.
The 4 Key Considerations
Work from home office spaces should be designed to facilitate clear communication for both the speaker and listener for any video meeting.
Often, the room needs to be redesigned or re-arranged to facilitate this and, in many instances, specialised acoustic treatments can be utilised to maximise the acoustical environment.
The goals for your home office should be good speech intelligibility and speech privacy. This means that the room should be acoustically conditioned to allow for the nuances in speech to be effortlessly conveyed and that you should also be free of distraction from external auditory disturbances.
The 4 key considerations are:
1. Internal noise levels
2. Reverberation time
3. Control of flutter echoes
4. Control of standing waves
Home Office Acoustic Design Solutions
The first step to acoustically designing a home office is to understand the acoustic criteria.
Internal Noise Levels
The Australian Standard AS/NZS 2107:2016 recommends internal noise levels of between 30 – 40dB in a video conference room. This should be satisfied if your home is within compliance to most Australian standards, which are usually designed to be under 35 or 40dBA in sleeping areas. One exception though is during aircraft flyovers which can be designed for a maximum noise level of 50dBA in sleeping areas.
Older dwellings may not be designed to standard, so a conversation with your acoustic consultant might be required. If you are able to though; you should select the quietest room possible for video meetings if you do have noise issues in your home.
Tips: It is important to seal any gaps in window frames and walls to the façade. This can be a major source of noise leakage in your home office. The smallest crack in your or facade can create significant noise intrusions in what could have normally been a great soundproofing wall.
Another concern are noise disturbances coming from within your own home. This can be mitigated by adding additional acoustic treatments to your office door or even upgrading it, as the door is often the weakest point of internal construction.
Reverberation Time
The Australian Standard AS/NZS 2107:2016 recommends a design reverberation time range of between 0.2 – 0.4 seconds for a video conference room. This is not very much reverberation at all. The longer the reverberation time the harder it will be to hear what others are saying and for others to hear what you are saying. The consonants will smear together with additional concentration being required leading to fatigue.
With the average home office size in being 2.8m x 2.5m for a small office or 4m x 3.3m at 2.4m ceiling height. This room will likely have carpet, office desk, chair, bookcase and possibly curtains. In both these scenarios the reverberation time would exceed what is recommended according to standard. The reverberation time can be measured on site or theoretically calculated as done in this example.
Tips: If your room is too reverberant; adding soft surfaces to your room will reduce the reverberation time. Things like plasterboard, glazing and solid timber are reflective and increase reverberation time where fabric or perforated acoustic panels, carpet and curtains are absorptive and reduce reverberation time. If you have solid floors like timber or tiles, then adding thick rugs will be beneficial.
Note: Acoustic panels are designed to absorb reverberation at a broad range of frequencies. An absorber such as carpet can cause excessive high frequency absorption, which can cause a room to be too ‘boomy’ which is not ideal for speech. It is important to remember that speech contains frequencies from as low as 80Hz up to 12,000Hz. The best way to acoustically treat any space for both cost efficiency and quality is in collaboration with your acoustic consultant.
Remember: The frequency of absorption, amount of materials and also the placement of absorbers are very important! Also, acoustic absorbers for reverberation control do not keep sounds in or prevent them going out. They do not soundproof!
Control of Flutter Echoes
Flutter echoes are a series of distinct echoes that repeat in succession. They are caused by hard surfaced parallel walls and heavily degrade acoustic comfort and speech intelligibility. They are the acoustic equivalent to ‘infinity mirrors’ and are usually associated with the mid to high frequency ranges.
You may notice that even in a small room with a short reverberation time that the acoustic comfort and speech intelligibility is bad. It can quickly become exhausting and you might find that you do not work as effectively in this room when it is time to communicate whether that be over the phone or video. This issue is flutter echoes at work
Tips: The solution is to place an absorptive or diffusive object in the flutter path minimising the interaction between the two walls. A bookshelf is an example of an effective diffusive object that can be used. The irregularities of the surface scatter the sound in different direction preventing the flutters.
This is also where placement when reducing the reverberation time using absorptive surfaces is important. You can effectively place the absorptive materials in way of the flutter path reducing both the reverberation time and the flutter echo simultaneously.
Control of Standing waves
Standing waves are caused by the low frequency build up in rooms that are too small to support these frequencies. The smaller the room the more issues with standing waves there will be. The problem is that they cause some frequencies to be attenuated and some to be amplified. This causes a negative impact on speech intelligibility. They can cause coloration on speech and impact how we hear vowels.
There are 3 type of standing waves that can occur. They are the interaction of low frequencies between;
· Axial –two surfaces in a room
· Tangential - four surfaces in a room
· Oblique - ALL six surfaces in a room
The particular frequencies are dependent on the rooms dimensions and can be calculated in order to understand the behaviour of a room. Using the theoretical average home office size from this article you would see frequencies 454Hz and below affected for the small room and 331Hz for the large room.
Tips: Low frequency absorber acoustic panels are effective at controlling room modes. In some cases where low frequencies are particularly problematic from external sources such as traffic annoyance, moving your desk and seating position can be helpful.
Conclusion
Your workplace is important, so important that you expect good acoustics. Your home office is just as important. With a little attention to your home office, there is no reason why you can’t have the same quality of acoustic comfort at home that you have in the office – hopefully your office had been acoustically designed in the first place!
Remember: that your acoustics designs don’t have to be ugly! There are many aesthetic solutions to keep your interior looking as great as it will sound after acoustic design. Bespoke solutions can also be created.
If you need any additional help with the tips in this article feel free to get in touch and consider Michael Phillips Acoustics for your next project!
Michael Phillips
Acoustic Engineering Consultant
M.A.A.S.
MArchSc (Audio & Acoustics), AssocDeg (Audio Eng.)
P: 0413 904 997
References
[1] Article 8557, Roy-Morgan-Coronavirus-Crisis-Impact-on-Employment-September-2020, Monday, 2 November 2020
[2] Article 8451, Roy-Morgan-Working-From-Home-June-2020, Monday, 29 June 2020
[3] The University of Sydney, Transport Opinion Survey (TOPS), Institute of Transport and Logistics, Page 2, September 2020
[4] McCrindle Research, Teleworking-in-Australia Research Summary, May 2013
[5] Twitter, Keeping our employees and partners safe during #coronavirus, 12 May 2020
[6] 451 Research (part of) S&P Global Market Intelligence, Covid-19 Flash Survey, June 2020
[7] The University of Sydney, Transport Opinion Survey (TOPS), Institute of Transport and Logistics, Page 16, September 2020
[8] McCrindle Research, Working from home: the benefits and the cost, June 2013
[9] Gajendran, R. S., & Harrison, D. A. (2007). The good, the bad, and the unknown about telecommuting: Meta-analysis of psychological mediators and individual consequences. Journal of Applied Psychology, 92(6
[10] Wolf CR. Virtual platforms are helpful tools but can add to our stress. Psychology Today. May 14, 2020. Accessed November 25, 2020. https://www.psychologytoday.com/us/blog/the-desk-the-mental-health-lawyer/202005/virtual-platforms-are-helpful-tools-can-add-our-stress
[11] Roberts F, Francis AL. Identifying a temporal threshold of tolerance for silent gaps after requests. J Acoustical Society of America, EL471. 2013
[12] Muhammad Sikandar Lal Khanb, Haibo Lia, Shafiqur Réhman - Gaze perception and awareness in smart devices, International Journal of Human-Computer Studies Volumes 92–93, August–September 2016
[13] American Optometric Association, AS#403:, Computer vision syndrome, https://www.aoa.org/healthy-eyes/eye-and-vision-conditions/computer-vision-syndrome?sso=y
[14] Mary E. Helander, Stephanie A. Cushman, and Shannon Monnat, Syracuse University, A Public Health Side Effect of the Coronavirus Pandemic: Screen Time-Related Eye Strain and Eye Fatigue, May 26, 2020
[15] What are the average room sizes inside Australian homes? 4 August 2020, accessed 25 November 2020, https://www.superdraft.com.au/trends/what-are-the-average-room-sizes-inside-australian-homes