Your upstairs neighbors’ sounds may be really annoying to you — especially if you’ve been working from home either full time or part time since the COVID-19 pandemic.
Yet there’s a larger issue to consider when this happens — and hope ahead.
A new study suggests that the “jolting” sounds created when someone walks barefoot in an apartment directly upstairs aren’t included in current standardized performance metric requirements of existing building codes, compared to other “impact sounds.”
That’s according to preliminary research presented in December at the 183rd meeting of the Acoustical Society of America, in Nashville, Tennessee.
“A peculiarity of impact sounds is that they’re impulsive — meaning that they consist of one or more almost distinct sounds of short duration, which draws the attention of an unintended listener more than continuous sounds, such as music or speech,” lead researcher Markus Mueller-Trapet told Fox News Digital.
Mueller-Trapet is a research officer and team lead for the acoustics team of the National Research Council of Canada, based in Ottawa, Ontario.
“This likely makes impact sounds more annoying in general,” he said.
“People reported that impact sounds from neighbors had an effect on their ability to work from home.”
With more people working at home ever since the pandemic, “the topic has become even more relevant,” Mueller-Trapet added.
“In a recent field study of Canadian apartment buildings, people reported that impact sounds from neighbors had an effect on their ability to work from home,” he also said.
Heart, sleep problems
Previous research has found that long-term exposure to these sounds can lead to heart and sleep problems.
Building codes have certain impact-sound requirements in place to help lower the risk of residents’ exposure to these sounds. For example, extra insulation or thicker walls might be required in buildings to help decrease transferable sounds.
“Studies have shown that impact sounds are one of the largest causes of residential complaints in multi-unit residential buildings,” Mueller-Trapet told Fox News Digital.
Using ‘lessons learned’
The international team, including researchers from Germany and Korea, set out to study the connection between building codes’ performance metrics and the perceived annoyance by the potential occupants using standardized laboratory measurements.
“In this case, we are using ‘annoyance’ as a proxy for how the occupants are affected by noise,” Mueller-Trapet noted.
“The goal was to provide a realistic acoustical environment for the study.”
“Our study aims to help provide data to motivate and inform the potential addition of an impact sound requirement in future editions of the National Building Code of Canada (NBC), with the explicit goal of using the lessons learned in other countries.”
The group had a floor-testing facility that resembled a living room, with two large chambers on top of each other and an assembly to test the sounds that traveled between these living areas.
“The goal was to provide a realistic acoustical environment for the study so that the participants could imagine themselves in a living room situation,” Mueller-Trapet said.
How were the sounds created?
People walked and dropped objects on the top-floor assembly as the researchers recorded the impact sounds.
They then presented these sounds to participants in different listening conditions, such as through headphones or loudspeakers.
“We used a spatial recording and playback technique called Ambisonics to create a realistic sound field for each listening condition,” Mueller-Trapet said.
To increase the sample size, the research group created an online listening survey, which began on Nov. 21, 2022, and will run until March 31, 2023.
The researchers acknowledged that the laboratory conditions in which the participants listened might not have modeled, in full, an actual living space — so they also studied the participants using a virtual reality headset to see how the results would change with a more realistic visual stimulus.
In all the studies, they used the same interface to provide the same sounds and asked the participants the same questions about how they perceived those sounds.
There were four different impact sounds in the study: a rubber ball dropped from two heights; a person walking barefoot upstairs; someone walking upstairs with shoes; and a metal hammer dropped from a certain distance.
The study compared the “annoyance” ratings for each of these sounds.
‘Unacceptable risk of illness’
The researchers found the performance metrics of the building codes were able to generally capture the annoyance factor caused by most impact sounds in the study — with one exception.
They didn’t capture the sounds created by barefoot walking.
“Our research will provide scientific data needed to help motivate and inform code development standing committees to propose a potential change …”
There was a limit, however, on how many people can participate because only one sound test could be run a time, the lead author noted.
To increase the sample size, the research group created an online listening survey, which began Nov. 21, 2022 and will run until March 31, 2023.
“Our research will provide scientific data needed to help motivate and inform code development standing committees to propose a potential change to the [National Building Code of Canada],” he noted.
The study “[aims] to reduce the risk that persons in buildings will be exposed to an unacceptable risk of illness due to high levels of impact sounds originating in adjacent spaces and transmitted through a floor assembly.”
“We would like to invite anyone who is interested in supporting our research to take part in our online listening survey,” Mueller-Trapet told Fox News Digital.
For anyone interested, the link for the English version is here: https://nrc-cnrc-construction.ca/online_listening_survey/index.html.
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