Congregational singing can be effectively stymied or greatly encouraged by the acoustical properties of the worship space. Recent trends in church architecture have unfortunately led to the use of more acoustically absorbent materials, which is harmful to this important aspect of worship. The following article provides helpful advice to remedy this problem.
Perhaps the greatest challenge in architectural acoustics is the worship environment. The acoustical characteristics within a worship space must cover the gamut from pristine clarity for the spoken word to enveloping reverberance for the pipe organ. The demands for room responsiveness exceed those of traditional concert halls and multipurpose performance facilities.
A closer examination reveals an even greater richness in this range of acoustical qualities. The speech end of the spectrum must accommodate all types of voices, from lay readers to seasoned preachers who will utilize every available nuance of the dynamic range—from a tumultuous shout to an intimate whisper to poignant silence. Through all this, the Word must be understood throughout the entire congregation.
At the opposite extreme is the pipe organ, capable of a dynamic range and frequency spectrum that can exceed that of a full symphony orchestra. And somewhere between the auditory alpha and omega are the choir and solo voice. They too must convey the Word with warmth and clarity, while encouraging and supporting the participation of the congregation.
Many of the difficulties of combining, within one structure, the requirements for speech intelligibility and musical resonance have been solved. Yet, if there is one facet of church acoustics that might be thought of as the neglected stepchild, it is the provision of appropriate acoustics for congregational singing.
Acousticians serving as consultants in church building projects, whether a renovation or new design and construction, are typically presented with a list of priorities during the initial stages. These invariably include a statement calling for “excellent acoustics for congregational singing.” However, as the project develops, this program element is frequently overshadowed or forfeited in compromise to other perceived needs.
Church renovation or construction projects involve an extraordinary variety of needs and priorities among the clergy and congregation. A church building project is, after all, a multifaceted undertaking and will typically involve
1. An organ. The selection and cost of an organ can be a major issue. Usually, a committee is appointed to study alternatives and make recommendations. They may spend a year or more touring neighboring churches, interviewing organists, and debating the pipe-versus-electronic and tracker-versus-electropneumatic issues. The installation of a significant instrument can easily exceed $500,000 and have major architectural and aesthetic ramifications.
2. A choir or music program. Here too a committee may be selected to address questions of placement of the choir, provisions for rehearsal space, new robes and robe storage, and so on.
3. A sound-reinforcement system. Another committee or perhaps one of the other sound-related committees should be responsible for the sound system. The system must amplify speech intelligibly and perhaps include provisions for music reinforcement, recording, playback, and so on. It must also be visually unobtrusive and preferably invisible.
4. Furnishings and finishes. The visual elements of the project call for many decisions regarding materials and colors, religious and art objects, seating, lighting, etc. This particular facet of the project is a major preoccupation for the architect who is deeply concerned about the impression the space will make, an overwhelmingly visual impression.
Too often the priority of congregational singing is overwhelmed by the high cost and visibility of other elements. When this happens, it is often assumed (or hoped) that if the worship space is designed to provide good acoustics for speech, organ, and choir, then it will naturally provide a welcome environment for congregational song. This is a reasonable-sounding assumption, but it is not necessarily true. To appreciate this, we might ask what is really known about the acoustical requirements for congregational singing and how these relate to those for speech intelligibility, organ, and choir. Before addressing these issues directly, let’s briefly consider a more fundamental question.
What Is Meant by Good Acoustics for Congregational Singing? This is indeed an intriguing question. When it comes to the qualities of the singing voice, research in acoustics has been primarily concerned with trained voices in the performance environment. This is not an appropriate paradigm for the common parishioner who may or may not be able to carry a tune, who may or may not even enjoy signing. Published studies dealing with the ordinary voice are generally geared toward open-plan offices, speech interference, telecommunications, and the like.
Let’s take a less pedantic approach, then, since there is little scholarship regarding the “optimal acoustics for the untrained voice as applied to congregational singing.” Let us consider some reasonable assumptions to motivate the formulation of acoustical requisites for congregational singing.
- The environment should provide support and encouragement for the untrained voice. It should sufficiently enrich and enhance the quality of the ordinary voice so that the singer feels encouraged to sing out, to participate in the communal act of lifting the voice in praise.
- The acoustic response of the space should impart to each individual in the congregation a sense of being a part of the assembly, an assurance that one is not alone or unduly exposed.
- The environment should convey to each parishioner the awareness that, as small as one’s contribution may seem, it is a meaningful part of the whole.
To summarize, the ideal environment ought to enhance the quality and fullness of the voice, provide a sense of envelopment, yet provide a sense that one’s simple gifts are an essential part of the whole and that this whole is profoundly greater than the sum of its parts. We seek, in essence, a sonic analog of unity, echoing the concept of the oneness of the assembly, while acknowledging the sanctity of the individual.
This is, perhaps, a rather grandiose concept; it surely exceeds the aspirations of even the most accomplished acoustician. But the concepts embodied in these lofty ideals suggest some well-understood acoustical principles. An insightful interpretation of these requirements can provide the proper acoustical conditions for congregational singing. Let’s take a brief look at some of the fundamentals involved.
Reverberation. Most people have some familiarity with reverberation time, the quality of sustain that occurs in large, hard-surfaced spaces. One need not be an acoustician to have some sense of the sound enhancement provided by a cathedral with a six-second reverberation time, a space where it takes six seconds for a sound to fade to inaudibility. Some of the more erudite may be aware that concert halls typically provide a reverb time of two seconds or more for symphonic music and that a pipe organ requires more than three seconds. There are many well-established benchmarks for “optimum” reverberation times for all types of environments and all forms of music. There are, however, no comparable reverberation criteria for congregational singing.
Nonetheless, reverberation is unquestionably a major and necessary factor for enhancing the quality of the ordinary voice in worship spaces. It also increases the loudness of a sound. Reverberation is, after all, made up of the myriad returns of acoustic energy from sound-reflective building surfaces. This energy combines with the original sound and increases the apparent loudness of the source. You might think of the analogy of a light source in a room. If the wall surfaces are covered with a dark, non-reflective finish, the overall illumination throughout the space will be less than if the finishes are light and reflective.
Sound-Absorbing Materials within the Worship Space. In most churches designed for good acoustics, there is a minimum of sound-absorbing material. In fact, in most churches, the single greatest sound absorber is the congregation itself. The fully clothed person provides about as much sound absorption as four to six square feet of conventional acoustical ceiling tile. A congregation of one thousand can provide as much sound absorption as an entire suspended acoustical ceiling over the nave!
It is fairly well-known that a certain amount of sound absorption is required to prevent echoes and to control reverberance. But it is not generally known that the performance of sound-absorbing material is strongly dependent on the location of this material relative to the sound source.
If a sound source is located quite far from a sound absorber and if this source is also projecting its sound away from the absorber, then the sound will have an opportunity to develop. It will blossom and begin to fill the room volume before the absorption begins to produce its sound-suppressing effect. In a church, these are generally the conditions that exist for sounds produced by the choir and organ. The major sound absorber (the congregation) is relatively far from the choir and organ, and both are oriented so that their sounds project directly into the full room volume. These conditions allow these sound sources effectively to utilize the available reverberation of the worship space.
If, on the other hand, the sound source is located near a major absorbing surface, the sound is directed (more or less) into the absorber, then the sound will be absorbed before it has a chance to be enhanced by the reverberance of the space. As we shall see later, these conditions fairly well describe those that exist for the voices in the congregation. In fact, it is a common perception, from within a congregation, that the choir and organ sound reverberant, while the congregation sounds rather dry in comparison. This is primarily a result of the proximity of the congregation’s voices to the sound absorption provided by the clothed bodies throughout the congregation’s seating area.
Sound-Reflecting Surfaces. Acoustically reflective surfaces are especially important for the support and distribution of unamplified sounds. A choir, if located near sound-reflective surfaces, can project its sound more fully and uniformly. A properly oriented overhead reflector can have enormous beneficial effects by projecting sound to the assembly and distributing sound among the choir members. A choral shell would be a real asset for a church choir, but such performance-oriented furnishings are considered by many to be inappropriate in the house of the Lord. Acousticians often attempt to introduce architectural elements that will perform the same functions as a choral shell while respecting the aesthetics and sanctity of the worship environment.
In much the same fashion, the voices of the congregation could make beneficial use of nearby reflecting surfaces to help distribute their sound throughout the assembly and provide support. However, only those singers near the perimeter will derive any advantage from sidewalls. There are rarely any usable overhead surfaces for the congregation since the needs for long reverberation require large room volumes and comparably great ceiling heights. The only available reflective surfaces are the pews and surrounding floor area.
Acoustical Requisites for Congregational Singing
We can summarize this review of acoustical factors with a statement of the obvious: Long reverberance and supportive reflections provide the foundation for delightful and awe-inspiring sound qualities of the archetypal church. These same factors greatly enhance the sound of the organ and choir and add a larger-than-life grandeur to speech.
It seems reasonable to assume that these qualities should also lend themselves to the need for congregational singing. They do. But they do not assure it. Nonetheless, large room volumes and long reverberation times are basic and minimum requirements for an environment that will encourage participation in congregational singing. We need to look just a bit further to see why these necessary conditions may not be sufficient.
Location and Disposition of the Sound Source. There is one feature of congregational singing that distinguishes it from nearly every other musical acoustic setting: The sound sources and receivers are in virtually the same location. Even more important, the sources and receivers are at the same physical height. There are few, if any, equivalent situations in musical acoustics. (There are some parallels in the acoustics of rehearsal rooms and stages, but the context and objectives are quite different.)
It should be evident that the height of a sound source, relative to the listener, is an important acoustical consideration. From an elevated position, sound is projected more efficiently and uniformly. The architectural acknowledgment of this principle is evident in the traditional form of music performance spaces. The principle is equally applicable in worship spaces. For example, the elevation of the chancel and celebrant takes advantage of the sound projection made possible by this simple height differential. The organ pipes and choir are typically elevated for the same purpose and are often located in a loft. Even within the choir, we typically find risers to take advantage of the enhanced projection of sound made possible by being elevated. Loudspeakers for the spoken liturgy are also placed as high as possible. Comparing these examples with the conditions in the congregation, we see that the assembly is at a decided disadvantage.
Another closely related factor is the directivity of the voice. The greatest concentration of sound energy from the untrained voice projects forward and down at a slight angle. Within the congregation, this tends to direct sound into the back of the person immediately in front. Most of the sound will be absorbed by clothing. What little remains to be reflected and scattered will be further absorbed by neighboring worshipers.
Pew Cushions and Carpeting. For the needs of congregational song, the use of any form of sound-absorbing material in and around the congregation is detrimental. It is not that these materials are the only cause of a poor environment for congregational singing. But, if we examine the most commonly occurring conditions in worship spaces, even in highly reverberant spaces, we see that the congregation already has several strikes against it:
- The congregation is typically on one level (except where there is a balcony) and cannot take advantage of the benefits to sound distribution provided by elevation, raked seating, or tiers.
- There are few, if any, proximal surfaces to produce supportive sound reflections and to distribute sound throughout the seating area.
- The congregation is engulfed in a sea of highly effective sound absorption. The ordinary clothing worn to services is absorptive enough, and in cold climates heavy outer clothing can increase the amount of effective absorption by 50 percent or more.
- To make matters worse, the normal directivity of the voice projects the sound energy from each member directly into this body of absorption.
The introduction of further absorption in the congregation in the form of pew cushions and carpeting is truly the final blow. It should be clear from the presentation above that this is a matter of physical fact, not simply the knee-jerk reaction of most acousticians who, as everyone knows, are always lobbying against the introduction of sound-absorbing material of any sort.
In fact, pew cushions and carpet produce, simultaneously, two effects that are directly contrary to the acoustical requirements for congregational song:
- They absorb sound and do so in a highly efficient fashion because of their proximity to the sound source.
- They occlude the floor and pew surfaces. These sound-reflective surfaces would otherwise be available to provide supportive reflections and to scatter sound among the assembly.
Pew cushions are generally considered to be a comfort issue as well as cosmetic concern. In truth, sitting on a contoured wooden pew for an hour is not a great discomfort. People of all ages are quite willing to sit in far less comfortable seating for even longer periods. Ballpark bleachers and park benches are two examples that immediately come to mind. This is really a matter of perception and priorities.
If pew cushions simply cannot be avoided, there are some alternatives that can minimize sound absorption. Cushions made with vinyl covering or fabrics with latex or vinyl backing will provide less sound absorption than the more common fabric upholstery. There are also closed-cell foams and alternative padding materials that offer adequate comfort without absorbing as much sound.
Carpeting is generally an aesthetic matter. There are many attractive hard-surfaced alternatives (for example, quarry tile, wood parquet, etc.) that would not introduce further absorption in and around the congregational seating area. If carpet is required for safety or to minimize the sound of footfalls, use the thinnest material possible and cover only the minimum area necessary.
Other Factors. Mechanical-system noise is of great concern in worship spaces. A noisy ventilation system can ruin speech intelligibility and cause distractions at the most inopportune moments. This same noise can have detrimental effects on congregational singing.
Consider the fact that background-noise generators are used in some open-plan offices to provide speech privacy and to reduce distraction from conversations and activities in neighboring areas. In such environments, an electronically produced “white noise” is used to drown out sounds from adjacent areas. The artificial noise effectively isolates areas by blocking or masking normally audible sounds. It is much like the effect of running water drowning out conversation in your home.
However, for congregational singing, we need to maximize communication within and throughout the entire sanctuary. A noisy background can greatly reduce the sense of support you would perceive from those singing around you.
Priorities and Compromises. Much of the foregoing has been a restatement of the oft-heard indictment against carpeting and pew cushions in the worship space. Hopefully, it has shown that if acoustics for congregational singing is a priority, then there are few options available, few concessions that can be made. There are no conventional methods that can offset the negative effects of sound-absorbing materials in and around the congregation.
It has also acknowledged the fact that church-building projects evoke conflicting priorities that call for compromise. There will surely be incompatibilities among the major areas of the project, for example, liturgy, architecture, and acoustics. There will even be disparities within these areas such as the conflicting acoustical requirements for speech and music. However, the acoustical characteristics required for choir, organ, and congregational singing are wholly compatible. These same characteristics (with a properly designed speech-reinforcement system) will provide the responsiveness necessary for the full range of liturgical oratory and actually enhance the richness and uniformity of speech distribution among the assembly.
It can be as compelling and uplifting as that which exists in any collective experience. While we might all wish for better singing voices, we must acknowledge that in some endeavors our God-given gifts are limited, but that we can be more than we are individually by being part of the whole. This is, perhaps, an idealized concept of the power of congregational singing, but proper acoustics within the sanctuary can help bring this concept to fruition.