by Dan Daley, Church.Design

Believing in what cannot be seen is a fact of life in religion. It’s also the case when it comes to acoustics, where sound interacting with the broadly variable geometry of church architecture can create anything from a heavenly aural penumbra around music to an echoic jumble around the spoken word.

In the past, knowing which way it was going to turn out was often as much a gamble as it was a sure thing. However, house-of-worship AV systems consultants and specifiers are increasingly turning to acoustical consultants and technology to help them know what a new or renovated church’s sonic future might hold.

Their tools are room-simulation and acoustical-evaluation software such as CATT-Acoustic, Odeon and EASERA. The platforms have been in use for about a decade, but their use has become much more widespread in the last several years, applied to a wider range of projects and venues, including more and more often, houses of worship.

 Shutterstock via Church.Design

Shutterstock via Church.Design

Weighing Costs and Benefits

“The software has become both more sophisticated and easier to use in that time, but don’t get the impression that it’s some $10 app for your iPhone where you just hit a button,” cautions John Storyk, whose WSDG firm has designed the acoustics for several hundred churches. “It’s still a science, and it takes understanding and experience to properly interpret and apply the measurements the software produces.”

As a result, there is a cost associated with using software to build virtual versions of planned or to-be-renovated spaces in which the sonic characteristics of various materials and angles can be accurately predicted. However, that cost can be little compared to what a good auralization, as the process is known, can produce in the way of savings.

Once a model is built, often from precise architectural plans that can be imported digitally into the software as data, acousticians can determine the coefficients for the absorptive, reflective and diffusive properties of various surface materials, by apply to them a range of sound sources to generate impulse responses, to measure the behavior of different types of sound against different types of materials inside a space whose architectural boundaries are known.

  Courtesy of WSDG

Courtesy of WSDG

Doing this digitally and ahead of construction or renovation can produce big costs savings. Storyk points to a church project in Switzerland where it was clear that the sanctuary would need absorptive treatment; what an analysis of an auralization provided, however, was exactly how much absorptive treatment was needed.

“It would have been easy to just eyeball it and say ‘we need this much,’ but that would almost certainly have resulted in using too much, to be on the safe side,” he says. “Instead, the graphs told us exactly how much to use and where to put it. In a large church, that can result in big cost savings.”

Auralization can work in a number of ways that can specifically help houses of worship. For instance, Storyk’s firm worked on an orthodox synagogue where the use of amplification or even electricity on certain days was forbidden. An auralization allowed WSDG to show the rabbi, listening over a pair of quality speakers or headphones, what his voice would sound like in the sanctuary with different types of acoustical treatments

Connecting Auralization and Architectural VR

David Evans, president of Kansas City, Mo.-based Mantel Teter, a provider of consulting, architecture and developing services to a range of clients, including houses of worship, says that auralization is complementary to the virtual reality (VR) processes he’s come to employ to give clients a more visceral sense of what to expect of environments and spaces that are still largely on the drawing board.

“VR can give clients and others who may have trouble envisioning what the experience of a space will be the ability to see and experience architecture the way we designers intend,” he explains. “VR accomplishes this is by allowing clients to do a walk-through of the spaces in first person at 1:1 scale, so they get to see the heights and views as if the space is already built … allowing the client to speak the same design language and take part in an iteration unlike ever before.”

Auralization, he adds, acts as the sonic counterpart to that VR walk-through experience. It provides, he says, “The ability to not only walk through a space before it gets built, but to also ‘listen’ to a space before it gets built.” In fact, he adds, it completes the sensory envelopment that will allow clients to fully experience their spaces-to-be in a way never before possible.

“Integrators and designers can now build models in a virtual environment where clients can use [VR] goggles, headsets, and listening devices to ‘hear’ a room before constructing it, just as architects now use VR to walk through buildings, allowing the client to control their journey and what they experience,” Evans adds.

Auralizations will only get better over time, as acousticians share their findings in a collegial manner, building the library of materials and coefficients that others can draw on. They can be run on reasonably powerful laptops now, and Storyk expects them to eventually migrate to smartphones, though the process will still need a trained expert to run it and interpret the findings.

“It’s been a game changer for me,” he says. “I couldn’t imagine doing the sound for a sizable church without it.”