Listening to a performer outdoors, the only sound you hear comes directly from the singer.
This direct sound is clear when you are close but becomes weaker and harder to understand the farther you are from it.
When you move indoors, other factors, like reflected sound and reverberation, can help increase a singer’s clarity, loudness and tone.
In an opera house, some of the sound from singing is directed away from the audience, say “up” to the ceiling. So hard surfaces overhead are designed to take some of that “unheard” sound and bounce it back to the audience.
This reflected sound merges with and makes the direct sound appear louder and easier to understand than it would be otherwise.
Here’s a look at some of the factors that will shape the sound in the Ellie Caulkins Opera House:
Direct sound
What you can see, you can hear. Line-of-sight sound comes directly from the singer to your ear.
Reflected sound
Sound bouncing off hard surfaces before you hear it, when combined with direct sound, makes a performance seem louder and clearer.
Reverberation
Some sound lingers, adding to the fullness, blend and sense of being in an unamplified musical space, rather than an amplified theater.
Sounds good
Strong, direct sound reaches a listener.
A strong reflection of the same sound reaches the listener within 50 milliseconds (1/20th of a second). The brain can merge these two sounds into one that is stronger but still very understandable.
A lingering cascade of increasingly weaker reflections gradually taper off about one and a half seconds after the direct sound. This reverb rounds out the sound and makes it more pleasent.
Merged reflection
Sounds bad
Direct sound is weakened or blocked before it reaches a listener.
A strong reflection of the same sound arrives after 80 milliseconds (which is still less than 1/10th of a second). The listener might hear it as a discrete echo that stands out from the smooth decay of sound.
The sound lingers too long and muddles the clarity.
Echo
The pit
The singers in the Ellie will use no amplification. In a concert, an unamplified singer can, with some exertion, be properly balanced with an orchestra on stage. An opera lasting hours would place severe strain on the singers unless the orchestra is muted in some way. This is done by placing the orchestra in a depressed area in front of the stageÑthe orchestra pit.
The Ellie Caulkins pit is split in two sections, each with its own hydraulic elevator. A large orchestra will set up on both sections, while a small orchestra (such as that used with Mozart or Rossini) can set up on only one section.
Both sections can be raised to floor level to hold additional rows of seating, or to stage level.
Some parts of the orchestra (like the loud brass sections) can be placed under the stage to further mute them. A movable wall under the stage, a first for any opera house, can adjust the space to achieve the perfect balance.
One elevator lowered for a small orchestra
Both elevators at seat level
Both elevators at stage level
Elevators at different heights can be used to blend quiet and loud parts of an orchestra.
Pipes and ducts
To reduce unwanted noise, plumbing and air ducts do not run through the walls that contain the opera house. Most pipes are routed through the space between the inner building (the opera house) and the outer shell.
Grates have been eliminated from the end of ducts to reduce noise. Instead, low-rev fans are used to drop cool air into the attic area directly over catwalks, which spread the air and block any remaining sound from the air system.
The ceiling
The ceiling is not solid but is a combination of hanging panels and openings into the attic.
Panels
The panels are designed to reflect sound down to the audience. The panels are made of gypsum (a mineral used in plaster, wall board and ornamental stone) reinforced with fiberglass thread. The panels are covered in wood veneer.
Attic
The openings into the attic effectively increase the hall’s volume for greater reverberance.
The walls
Reflective
The walls close to the stage are folded upÑlike an accordionÑto create a series of angles that reflect sound toward the center orchestra seats, those seats farthest from the ceiling reflectors. The accordion walls are made of several layers of gypsum boardÑmaking them very stiff and reflectiveÑand are tilted out over the floor so that sound from the stage doesn’t fly over the audience, but instead is deflected downward.
Absorbing
The walls farther from the stage (including the back walls) are covered in fabric to stop sound from creating too much reverb and bouncing back to the stage, which could interfere with the performance.
Blocking
A 12-inch thick concrete wall wraps around the seating area from floor to ceiling. This helps block outside noise from interfering with the performance.
The balconies
The balconies are not stacked like pancakes but designed like steps. This allows all seats to be exposed to reflected sounds and reverberation.
The stage
The opening of the stage, called the proscenium, is 55 feet wide, somewhat narrower than a concert hall. This allows for walls to be closer to the center orchestra audience, creating the proper sound reflections so important to the clarity of speech and song.
