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

September 21, 1986|ALLAN JALON | Allan Jalon is a Times staff writer. and

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 \o7 do \f7 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.

\o7 Architects and Acousticians \f7 "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.

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