FROM THE GROUND UP : Sound Advice : Acousticians’ efforts can dramatically affect the richness of a Beethoven symphony, the crispness of a Shakespearean speech

It happens with almost every new performing arts center. The management hires an acoustician with an “innovative” theory. Fund-raisers promote the person’s ideas. A community’s expectations soar.

So it goes as the Orange County Performing Arts Center prepares to open Sept. 29. With a touch of Madison Avenue, a fund-raising newsletter for the center has promised a “rich palette of exciting listening experiences” and “exceptional acoustics throughout the theater.”

If the center lives up to these promises, it will indeed be an achievement, because the annals of acoustic architecture are strewn with disappointments. From New York’s Philharmonic Hall to the Dorothy Chandler Pavilion in Los Angeles, opening night has led to a search for acoustical improvements.

Yet, the quest for good acoustics--a widely discussed aspect of a new theater’s design--is also the least understood. In the aftermath of acoustical disappointments, laymen invariably express bewilderment. Why, they ask, is it so difficult to fulfill those glowing promises about a building’s all-important ability to project sound?

The answer lies in the work of the acoustics consultants, who play a key role in nearly every aspect of theater design. They dramatically affect the quality of performances: the richness of a Beethoven symphony, the crispness of a Shakespearean speech. They usually work on an equal footing with architects to design a hall’s interior. The height of a ceiling, the width of the seats, the thickness of carpeting--all can influence the sound waves produced by a voice or an instrument.

Size also is an important factor, with larger halls tending to diffuse and deaden sound. In terms of acoustics, large means more than 2,000 seats. The Costa Mesa center has 3,000.

Some acousticians are physicists, but the field draws on experts with a range of knowledge, from architecture to music. Acoustics is too subjective to be fully a science, too systematic to be an art.

Still, there are some objective basics. A sound wave, like light, travels in straight lines from its source until it meets an obstacle. Then, it is reflected or absorbed, depending on the material it encounters. Its volume is usually measured in decibels, units that describe the relative loudness of sounds. In the controlled climate of a modern concert hall, sound moves at a constant speed of about 1,100 feet per second, or roughly a foot per millisecond. Outdoors, it speeds up in hot weather and slows down in extreme cold. Its intensity, or what the listener perceives as loudness, gets weaker in proportion to the distance it travels.

Many acoustic projects--from soundproofing submarines to erecting noise barriers along freeways--involve shutting out sound. Designing a concert hall means building for the sound you do want. For performances of classical music, by which such a hall generally is judged, one wants clarity and warmth. Connoisseurs talk reverently about the sense of “acoustic intimacy” found in the best halls. Failure is usually defined as sound that is dead, dry or too reverberant.

Architects and Acousticians “An architect hears with his eyes, an acoustician sees with his ears,” says George C. Izenour, a world-renowned theater designer. Professor emeritus of theater design at Yale, Izenour has contributed a number of acoustic innovations over the last 30 years.

In designing the Orange County Center, the three acousticians on the project--Jerald Hyde, Dennis Paoletti and New Zealander Harold Marshall, one of the field’s pioneers--were given great freedom to test their confidence in a theory that has come to the forefront of acoustic research over the last decade.

Emphasizing the importance of “early lateral reflections,” the theory is not as complicated as it sounds. The idea is built on the observation that acoustics are enhanced when sound is reflected toward the audience from the sides of a theater.

The Orange County center’s interior is an array of acoustic mirrors--angular walls, jutting balconies, choppy ceiling shapes. It looks like a piece of a honeycomb, a kind of architectural Cubism. Even when architects proposed more traditional shapes, the acousticians persevered. The asymmetry of the interior dictates the shape of the entire center.

Around the country, acousticians are impressed by descriptions of the center that they have read in engineering journals. But until opening night, no one can answer the key question: Will the design work?

Charles Lawrence, the Costa Mesa theater’s lead architect, says he has faith in the acousticians’ strategy and noted that tests on a model of the hall built in New Zealand portended a happy outcome. Yet, he is among several people who have cautioned that experiments, even when they cost $70.7 million, as this one has, are not guaranteed to succeed.

An unbiased appraisal of the building is hard to find. Most of the country’s prominent acousticians applied to work on the Orange County project, which was considered a professional plum. Off the record, acousticians tend to turn highly competitive, casting doubt upon their colleagues’ theories. (One acoustician, who lost the job to Marshall’s team, said of the New Zealander:”I think he’s out on a limb with this one.”)

A more disinterested observer is Michael Forsyth, professor of architecture at the University of Bristol, England. (In 1985, MIT Press published Forsyth’s well-regarded book on acoustics, “Buildings for Music.”)

Forsyth has studied blueprints of the Orange County center and has written a chapter on it in a forthcoming work on the acoustics of multipurpose halls. The theory of early lateral reflection is the cutting edge of acoustic thought, he says. The center is the theory’s most complete embodiment to date.

“It is sort of an eccentric building,” Forsyth says. “But one has to see it in terms of the broad concepts and development in the field.”

Scientifically Designed Halls

Boston’s Symphony Hall is widely regarded as the best concert hall in the United States. It also was the first hall to be designed scientifically, in contrast to the intuition and luck that guided the construction of its predecessors. The acoustics of Symphony Hall, which opened in 1900, were calculated by Wallace Clement Sabine, a professor of physics at Harvard. People knew that certain rectangular buildings in Europe, so- called “shoe-box halls,” sounded terrific. But efforts to imitate those successes often failed.

Sabine wanted to know why.

He chose as a model the Leipzig Gewandhaus, a 1,560-seat hall in Leipzig, Germany. It was one of the European examples whose builders had achieved highly fortunate, if unexplained, results. The Boston hall’s backers considered other shapes at first, but they allowed Sabine to pursue his course.

Sabine set out to design a structure with 1,040 more seats than the Leipzig hall. Increasing the size of the design without diluting the acoustically refined impact of its architecture was the challenge that faced him.

Sabine, only in his late 20s when he worked on the hall, had already observed that, in some rooms, sound would linger long enough for the listener to revel in its fullness. In others, the music would die away before it could be enjoyed.

Yet another room would throw notes at a listener so aggressively that none could be heard distinctly. Sabine wanted to distill these observations into an algebraic formula. The effort took two years. Working with a stopwatch, Sabine timed changes in the duration of organ blasts within theaters in Boston. He worked at night, between the rumblings of passing streetcars. Filling a hall’s seats with pillows, he would take one reading, then add or subtract pillows and take another.

He wanted a formula that would explain--and thereby help him predict--exactly how any hall would affect a sound’s “reverberation time,” as he called the time it took an orchestral chord to fade.

According to an anecdote recorded in Sabine’s papers, he discovered the solution on an autumn night in 1898, shouting across the house: “Mother, it’s a hyperbola!”

The first major acoustic principle, as observed by Sabine: The harder a hall’s interior surfaces and the greater its overall volume, the more reverberant it will be.

An example of too much reverberation would be found in a Gothic cathedral, with its booming echoes. The opposite extreme would be a padded cell, which sops up sound and renders it lifeless.

Ideally, Sabine concluded, a chord should linger for two seconds. With that goal, he calculated the ceiling’s height for Symphony Hall--57 feet over the stage and 61 feet over the auditorium. He carefully selected and directed the shaping of its hard plaster. The measurements paid off. The hall’s reverberation time is 1.8 seconds.

The sound there is indeed remarkable. A recent performance of Elgar’s “Enigma Variations,” with its lush and dynamic string passages, showed off the hall’s strengths. The walls reflected the emotional heart of the chords. As the Boston Symphony Orchestra played, one listener had the feeling that the building itself was an instrument.

But Sabine’s accomplishment did not spur a tradition of acoustic success; other factors took over the shaping of concert halls.

There was an economic demand for larger theaters that could bring in more revenue. Aesthetic tastes brought in thick carpets and drapery--which absorbed sound like a sponge. Some consultants praised the “clarity” of this drier type of sound in these larger, plushier halls of the ‘40s and ‘50s. Architectural style challenged the shoe-box shape, experimenting with funnel shapes that mimicked the effect of the speaker horn of an old-fashioned gramophone.

The first of these so-called sound-directed halls was the Salle Playel. Constructed in 1927 in Paris, it was a disappointment. But the principle on which it was based--shaping a hall to direct the path of sound--gained influence. A few examples built in the ‘30s, ranging in size from 1,955 seats to 2,839, proved more successful, but not consistently.

The end of World War II brought a concert-hall building boom. European halls had to be rebuilt. The United States saw a new hunger for cultural experience. The demand was for large halls, but with the best possible sound.

In the ‘50s and early ‘60s, acoustics became an especially important part of the promotional drama surrounding a new hall. The public’s admiration for all kinds of technology swelled.

Thus it was front-page news in the New York Times when a Boston acoustician who had designed New York’s Philharmonic Hall began testing it in May, 1962, five months before the opening.

“Shots From the Stage Will Be Heard by Dolls With Electronic Ears in a Test of Acoustics on Monday,” the headline proclaimed.

The acoustician was Leo L. Beranek, a traditionalist who generally held to Sabine’s Boston design. This would be a rectangular room with straight side walls and 2,400 seats. (The 2,600 seats Symphony Hall was designed to hold are less upholstered and placed closer together than seats used in such facilities today. The hall would probably hold closer to 2,100 seats, were they designed by standards used in Philharmonic Hall and most contemporary halls. Symphony Hall still uses the original seats, and the number of them is sometimes increased by a few dozen to accommodate larger audiences.)

In the New York Times article, Beranek sounded like someone who knew what he was doing: “Mr. Beranek has done a study of 54 concert halls and auditoriums around the world,” the Times reporter wrote.

But opening night on Sept. 23 was one of agonizing discovery. Notes in the lower frequencies sounded weak. Musicians couldn’t hear one another play. The outcry that followed was heard the world over.

Beranek took much of the blame in the debacle. Today, he says the situation was judged prematurely and people did not fully understand what had happened.

The architect had added 258 seats to the theater, pushing the walls into a barrel shape, despite Beranek’s recommendations. A sound booth was also added at the last minute, further diluting the acoustic design, Beranek said in a telephone interview.

He was not given the chance he wanted to make adjustments, even though he always thought some adjustment might be needed. The interior of the hall, renamed Avery Fisher Hall, was entirely rebuilt under the acoustic guidance of Cyril M. Harris of Columbia University. Ironically, the end result was quite close to Beranek’s original design--and Sabine’s.

The episode made the price of acoustic compromise--in this case, 258 seats--shockingly clear. But economics only forced more daunting compromises upon acousticians in the following years.

The Rise of Multipurpose Halls

New York’s Philharmonic Hall was purely a concert hall. The Lincoln Center complex had other theaters for opera or drama. Some communities find it financially impractical to build separate theaters for each function. So they settle for multipurpose halls, often with 2,000 or more seats, in which they try to present every kind of performance.

But different types of performers have varying acoustic needs. An orchestra generally wants reverberation. An actor likes a dry chamber where sounds won’t have the aural afterglow that mars diction.

Many times, the theater designed to please everyone leaves enough people unhappy to spur costly corrective measures. In Los Angeles, a $3.5-million plan is being considered for the acoustic renovation of the 3,200-seat Dorothy Chandler Pavilion, a multipurpose facility.

Management, along with some musicians, says that the difficulties are relatively minor. But other musicians and conductors are quite critical. Thomas Stevens, the L.A. Philharmonic’s principal trumpet, was quoted in The Times as saying that “dynamics tend to get lost” and has called the Pavilion an “acoustical turkey.”

Columbia’s Harris, perhaps America’s best-known acoustician, says he refuses to design multipurpose theaters as a matter of course, finding that they impose a degree of compromise he does not tolerate. Aside from his efforts on Avery Fisher Hall in New York, Harris has been praised for his work at Washington’s Kennedy Center.

Other acousticians have not abstained from the problems of designing multipurpose theaters but have tried to come to terms with them. The search for new methods has led to theaters with movable walls and ceilings.

The first extensive use of this acoustic method came in 1966, at the Jesse H. Jones Hall for the Performing Arts in Houston.

Its ceiling is composed of about 800 hexagonal steel panels that can be raised or lowered by computer command to adjust the “acoustic space” of the 3,000-seat room. The panels can seal off the highest of the two balconies, forming a recital hall. But operations managers have had technical trouble operating the $1-million system. “We’ve used it maybe one or two times,” said Tony DiFazo, the hall’s chief stagehand.

A similar movable ceiling in the Edwin J. Thomas Hall in Akron, Ohio, works better, but critics and musicians say that its billowing, sail-like construction really does not bring the hall the reverberation it needs. “Most of these (multipurpose) halls are bad,” says Bob D’Angelo, who runs Thomas Hall. “We are in the upper ranges of mediocre.”

In Silva Concert Hall in Eugene, Ore., which opened in the city’s new Hult Center in 1982, dozens of small microphones and speakers in the ceiling amplify and recirculate sounds from the stage. Andrew Porter, music critic of the New Yorker magazine, praised the hall. Others say the sound is “inauthentic.”

Performing Arts Center

The Orange County Performing Arts Center is the most recent experiment in acoustics within a multipurpose hall and is being closely watched by acousticians and musicians around the country.

It will not rely on a movable ceiling, although there are several sound-absorbent curtains that can be raised and lowered. It has a speaker system somewhat like the one in Eugene, but the system will be used mostly for drama performances.

The key to understanding the center, particularly as a concert hall, lies with the acoustic research--conducted during the ‘60s and ‘70s--into how people perceive sound and the importance of sound reaching the ear from the sides of a theater--the lateral reflections.

Acousticians now define Sabine’s theory of reverberation as what happens to a sound in its first 50-80 milliseconds. That first instant of a sound’s life is the current preoccupation among acousticians--especially with center acousticians Hyde, Paoletti and Marshall. Hyde and Paoletti, both based in California, are respectively a physicist and an architect. Marshall was trained as an architect, engineer and physicist and teaches architecture and acoustics at the University of Auckland. He is regarded as the hall’s conceptual father, with a lot of input coming from his colleagues.

“We’re looking for a sequence of reflections that reach members of the audience after different periods of time,” Hyde said. “There would be four or five different reflections within the first 20 to 80 milliseconds.”

The ear hears such separate reflections as one constant aural impression, just as the eye sees--but does not distinguish--the separate pictures that make up the continuum of a movie.

The Orange County team believes that this rapid-fire pattern of impressions from the sides will make the listeners feel that they are “enveloped” by sound, to use one of Hyde’s favorite words.

“We were given pretty much free rein by the architect to develop that design, and as far as I know, there were no significant compromises,” Hyde says.

(The one concession made was in the acousticians’ favor. Originally, Hyde said, the center’s backers wanted the hall to be even larger--3,200 seats. But the number was dropped after nearly all the designers--acousticians and architects alike--warned that planning for more than 3,000 would be ill-advised.)

Hyde and his colleagues use Symphony Hall in Boston as an analogy for the kind of acoustical intimacy they want audiences to experience. Lawrence, the architect, describes the sides of the center’s four staggered tiers as adding up--acoustically, if not visually--to “two shoe-box theaters that focus on the same common stage.” But even coming close to Sabine’s results in a multipurpose theater would be an internationally recognized achievement.

“I think it’s going to be absolutely fabulous,” says Hyde, when asked for a prediction about the center’s acoustics. “It will be a hall with a tremendous dynamic range, from the softest triple pianissimos to quadruple fortes. It will be very sensitive to the musicians.”

As for the hall’s suitability for speech, Hyde is equally optimistic. “I dare say that a person will be able to come out onto the apron of that hall and communicate with people throughout the entire 3,000 seats,” he says, although he admits that some straight drama will need amplification. However, acoustic historian Forsyth says he has some reservations about the Orange County team’s zealous application of the theory of early lateral reflection. Overly powerful reflections, he said, could make the sound too harsh or shallow.

(Marshall acknowledges that this was a “minor problem” with Christchurch Town Hall in New Zealand, which he designed and which opened in 1972. “The problem was noticed only by people sitting close to reflective surfaces,” Marshall said in a telephone interview from Auckland. He also said he avoided the problem when he designed a hall that opened in Wellington, New Zealand, in 1984.)

The Orange County center “is very much the projection of an idea into three-dimensional form,” Forsyth says. “But it is carried out so logically into three-dimensional form that it has been taken to a sort of crazy extreme.”

Hyde, who collaborated with Marshall on a 2,700-seat symphony hall in Wellington, New Zealand, called Forsyth’s speculation “preposterous” because the hall has not yet opened.

Marshall, whose access to testing facilities in Auckland has allowed a model of the Orange County center to be built and tested in New Zealand, has said that extensive testing indicates the hall will fulfill his expectations for opening night.

But from another acoustician, who is only too familiar with the risks that accompany high expectations, comes this advice:

“Don’t make flash judgments,” Leo Beranek said in a recent interview from Boston, where he sits on the board of directors of Symphony Hall. “Take it easy. It’s always possible to make adjustments.”