When Charles Garnier designed the Paris Opera in the 1870’s, he said that architecting the acoustics of a room was a “bizarre science.” Garnier compared the acoustician to an acrobat “who closes his eyes and clings to the ropes of an ascending balloon.”
More than a century later, how sound moves through a room is still sometimes a mystery.
At the spherical Mapparium, a so-called “whispering gallery” in Boston, sound sometimes behaves in strange ways. In some parts of the room sound seems to come from strange directions and it appears to double in volume if two people stand precisely two meters from the room’s center. Nobody is precisely sure why.
The Disney Concert Hall in Los Angeles is considered one of the finest acoustic spaces in the world, its sound architecture hailed as “perfect.” Yet when the acoustician behind it, Yasuhisa Toyota, was asked how he achieved that perfection, he said that after making small models to test sounds and make adjustments, “all we can do is just pray.”
Architectural acoustics as a discipline was founded at the end on the 19th century, when a young Harvard physics professor named Wallace Clement Sabine sought to understand why the students in a new lecture hall could never understand what their professors were saying. Sabine discovered there was too much reverberation. If one syllable was spoken too quickly after another, their sounds would collide as they bounced off the ceiling, the floors, the walls, the furniture and people in the room. He proposed a solution: adding sound-absorbing materials to the walls. Afterwards, at long last, the students could hear.