Well at Work: Sound Off!

― Well at Work

Sound Off! "When we can foster the correct balance of acoustics and focus, building occupants are able to accomplish more.

There are a number of solutions that can be implemented to ensure proper acoustics are achieved. These are best done in design when those decisions can be made as part of the overall intent of the space."

- GARRETT FERGUSON, PERKINS AND WILL

Acoustical Terminology: Noise Reduction Coefficient (NRC) is a measurement of how much a material can reduce the noise by absorbing that noise. Fiberglass, foams, and perforated materials tend to have a higher NRC than harder materials which will bounce the noise around. For open plan work areas target NRC 0.90 or higher.

Panelists Garrett Ferguson Perkins and Will Erika Eitland Perkins and Will Marcelo Bernal Perkins and Will Omar Longoria SLR Consulting

Moderator Julie Gauthier Perkins and Will

Ceiling Attenuation Class (CAC) is a measure of a ceiling tile's ability to block sound from traveling room to room. A ceiling tile with a CAC < 25 is considered low performance, while a CAC > 35 is high performance. CAC should be considered for Enclosed offices to help with "blocking" sound from migrating to other spaces.

Reverberation is defined as the time in seconds that it takes sound to decay or "fade away". By 60 dB. For example, if you clap your hands in a large room, you should be able to count (one one hundred) how long it takes to die out so that it is inaudible. Sound in a room with no absorption will repeatedly bounce off surfaces such as the floor, walls, ceiling, windows or tables.

D50 is a ratio of the early received sound (0-50ms) to the total received sound and measures the clarity or intelligibility of speech. Strength is mainly influenced by the sound absorption of the room and distance between sound source and receiver.

Sound Masking provides a continuous and targeted background sound through the use of frequencies generated by the system that align with the speech spectrum. The purpose is to elevate the background sound in a space so that speech is less intelligible. Introducing sound into the space to "mask" speech â&#x20AC;&#x201C; not block noise. These systems must be tuned properly to ensure that key speech intelligibility frequencies are masked.

Hertz (H) unit of frequency related to the length of the sound waves. It is classified in 8 bands from 62,5 Hz (a track) to 8000Hz (white noise). It turns out that our ears are most sensitive in the frequency range between 500 Hz and 4,000 Hz.

Strategies for Noise Control nj Maximize Sound Transmission Class (STC) nj Add sound masking to improve speech privacy if the space usage allows nj Use acoustically rated doors in office fronts where speech privacy is important nj Add absorption materials in the partition cavities to improve performance

"There is not one element by itself that achieves overall acoustic comfort."

- OMAR LONGORIA, SLR INTERNATIONAL

nj Seal the gaps or small cracks of the envelope to minimize transfer of sound through an assembly

Achieving Acoustic Comfort What is Acoustic Comfort? - it is the reduction of unwanted sounds and enhancement of wanted sounds To achieve acoustic comfort requires a holistic approach achieved through balance and control of key parameters: nj Sound absorption nj Sound isolation nj Background noise

Proper application of these parameters helps to achieve specific acoustic criteria: nj Speech Privacy – example – for a conf room adjacent to office need to use all three parameters nj Speech Intelligibility – example – inside a meeting

Additional Information and Resources: Face Masks will hinder speech communication in the office environment from The National Center for Biotechnology Information whose mission it is to advance science and health by providing access to biomedical and genomic information.

room/conference room/training room – need to balance all three nj Noise Control – example – office next to mechanical room, mainly need sound barriers

The Facility Guidelines Institute (FGI) offers additional information on Sound Transmission Class (STC) in room adjacency.

Sound absorption is one of the parameters in the WELL Building Standard to achieve acoustic comfort.

Perkins and Will's AT HOME Survey This survey was designed to capture the top challenges/improvements by being at home; understand task effectiveness, as well as cultural and social factors. If you are interested

Special thanks to Omar Longoria with SLR International.

in conducting an AT HOME Survey with your organization please contact us!