How to Favorably Affect Acoustics
By: Andrew Glasmacher
Church architecture has evolved over thousands of years with many different faiths affecting the appearance and utility of religious buildings.
Today, houses of worship range from very small and simple structures to grand and ornate cathedrals and temples. A variety of materials such as stone, brick, concrete, hardwood, and glass are used in the construction of churches, with many design cues influenced by aesthetics or convention.
With this huge diversity in church buildings, there is one common trait they often share—poor acoustics. Yet, acoustics should be at the very top of the priority list when designing a house of worship.
One of the primary functions of a church building is the sharing of a message, often spiritual in nature, and the delivery style of these messages is a large part of what makes them meaningful.
In more traditional church environments, a pastor or priest typically speaks to congregants and some portions of the service may be read by a member of the clergy. This alone can be problematic as everyone has a different speaking style and volume, and these traits can make intelligibility extremely difficult, especially among those who are hard of hearing.
More modern churches might incorporate a worship band into their service, creating high sound pressure levels (SPL) in many cases.
Acoustic properties of a church building can have a major impact on intelligibility and congregants’ overall enjoyment of a service.
Hard surfaces in construction can cause audio artifacts such as reverberation, echo (delay), amplification of some sounds, and even cancellation of frequencies. Reverberation can be defined as the collection of reflected sounds from the surfaces in an enclosure like an auditorium.
In some cases, reverberation can enhance and reinforce the sound of a performer such as a singer in an opera house. An echo is the repetition of a sound caused by reflection of sound waves from a surface.
The larger the space, the longer it takes for the echo to reach the listener and in extreme cases, the echo can be as loud as the direct sound, delayed several milliseconds to a full second or more.
In large spaces such as museums, stadiums, or large church buildings, the effects of reverberation and echo on intelligibility are immediately perceptible. The reflected sounds interfere with the direct sound and often make it difficult to understand what is being said by a pastor, tour guide, or announcer.
With many churches incorporating live music in their services, the addition of musical instruments and amplification contribute to the amount and level of sound being sent to the listener, and an overly reverberant room can become quite uncomfortable as the SPLs increase.
When design philosophies or budgetary restraints make structural changes to the building impossible, the best way to improve the acoustics are by applying treatments. Acoustic treatment is a science unto itself and best results can be obtained by consulting a reputable acoustician.
Acousticians spend years developing their knowledge of how building materials, room size, and other factors affect intelligibility.
There are several types of acoustic treatment that could be employed as well as some aesthetic features that could also favorably affect acoustics in a church.
Carpet can also help reduce distracting background noise by softening footfalls of people walking in the aisles and reducing the impact of items dropped onto the floor.
This can make it easier to hear and understand the direct sound coming from a podium or public address system. The heavier and thicker the draperies, the more sound they can absorb.
Panels come in a variety of fabrics and colors and can be custom-made to match the décor. They can be made in many shapes and sizes to help with placement options. As this is a semi-custom option, it’s always a good idea to involve an acoustician when choosing panels.
Feedback is often used in movie scenes to give the viewer a cue that a live microphone is being used, but in actuality it is something to be avoided.
Feedback can occur when the loudspeakers are either too close to or behind the microphones. It is caused by sound from the speakers “feeding back” into the microphone and being re-amplified with the result being a loud squeal or screech.
Speaker placement is a key factor in how well the sound reinforcement system can reproduce sound without feedback.
It is also important to consider the types of microphones that will be used. Does the pastor prefer a lavaliere or handheld microphone? The type and pickup pattern of the microphone can greatly affect sound quality and resistance to feedback.
Ideally, speaker systems should be placed not only to avoid feedback, but also to provide even coverage throughout the space. Here are some things to consider:
* Does an area such as a cry room or overflow annex need audio coverage?
An audio consultant or system integrator should always be involved in the design of a venue that will be utilizing amplified audio.
Try to choose one who specializes in the type of venue you are building. They are experts at making sure every word is heard and understood, as well as providing the best possible quality of audio for your budget.
Remember, the time to consider acoustics and audio systems is in the design phase, when at all possible. Good acoustic design and acoustic treatments will assure none of the spiritual message gets lost.
Andrew Glasmacher is Listen Product Training Manager at Listen Technologies, a leading provider of assistive listening products for more than 17 years, www.listentech.com.