Understanding Acoustic Ratings in an Evolving Market

As the construction market continues to flourish, acoustic performance is becoming a prominent consideration in the development of new and retrofit projects. The growth in population, urbanization and a thriving construction industry continue to drive the market forward. LEED specifications also underline the importance of acoustics in designing comfortable spaces.

Society itself is becoming more sensitive toward how noise pollution affects humans. According to the CDC, one in four adults show signs of noise-induced hearing loss. This makes safety and occupant comfort a critical component in new construction. There has also been an uptick in retrofitting commercial spaces for higher acoustic performance, including those located near busy airports.

As an industry, it’s important to be cognizant of how we can propel acoustic performance forward. While there are many aspects of an interior space that can make an environment comfortable, exterior facades are key.

The type of glass and fenestration used on a building are primary considerations in obtaining the desired level of acoustic performance. Adding high-performing panels to storefront or curtain wall is a common and effective solution as it pertains to retrofit buildings. However, new facade innovations designed to improve acoustic comfort continue to grow. As they do, it’s critical to understand acoustic ratings to ensure proper product selection, installation and desired outcome. Some vocabulary to know: 

• A Sound Transmission Class rating specifies noise transmission from room to room.
• An Outdoor-Indoor Transmission Class rating specifies noise transmission from outside to inside.

The STC rating has been around for decades and is often relied upon as the go-to rating for soundproofing a building. The OITC rating, established in the ‘90s, is newer to the industry and is often overlooked in favor of the STC rating.

While both are effective, it’s important to apply ratings to the right scenarios to provide the highest level of occupant comfort: 

• An STC rating is often sufficient for a project that is soundproofing walls between offices, hotel rooms or condo units.
• The OITC rating is necessary for commercial buildings that are close to an airport or in an urban core.

Additionally, it’s important to understand the frequency of the noise to dampen: 

• Lower frequency noise, such as air traffic, or
• Higher frequency noise, such as train/subway noise.

A product may have a great STC or OITC rating, but struggle with dampening a particular noise frequency. Product test results are a great way to evaluate this piece of the acoustic puzzle. When a product is tested, the transmission loss is recorded in multiple frequencies, as the entire sound spectrum is tested, which helps to pinpoint performance based on the surrounding environment.

As the market continues to become more sophisticated in acoustic performance, pay close attention to the specified rating. Ask questions to ensure it is correct before moving forward on the job. One day, the building’s occupants may thank you.  

Heather Evans serves as certification program engineer at YKK AP America Inc. She joined YKK AP in 1999. Heather spent several years managing and implementing collateral and estimating software before joining the Product Development team in 2016.

The opinions expressed here are those of the individual author and do not necessarily reflect those of the National Glass Association, Glass Magazine editors, or other glassblog contributors.