Sound ideas

Acoustics are key to the success of most performance venues, but there is no single best acoustic for all performing arts. What is an appropriate acoustic for a particular performance depends on the art form, and even the particular work. What are considered excellent acoustics for a symphony concert are different from what is considered excellent for drama, and that is different from excellence for opera. If a venue will be used for a range of different arts or repertoires, good sound for one may not be good for another. The acoustics should support the artistic intentions. What is to be communicated through the sound? Pure information, as in a lecture, or the colour, emotion, rhythm, texture and dynamics of classical music? In drama both are important – the room should transmit the actor’s words and emotion clearly to the furthest seat. In amplified concerts the acoustic is important too – the room must ‘disappear’ to leave only the sound of the loudspeakers.

Architects of sound
Architecture has evolved over the years along with the art forms that inhabit buildings. The early history of music was intertwined with the history of architecture and the Church. Composers wrote music for spaces they knew, either vaguely or specifically. As architects and engineers developed structures that could span farther, we began to see wider theatres and concert halls, larger seat counts, deep balconies. After many decades of ‘bigger is better’, and a precipitous drop in acoustic quality in the post-war years, we began to understand why smaller is better, and to prioritise acoustic quality. In order to achieve acoustics well matched to the artistic programme and quality aspirations, the first step is to install committed leadership from the start of a design process from the top of the arts organisation. The client teams for the Sage Gateshead and Birmingham Symphony Hall were committed to acoustic excellence from the start, and kept their collective eyes on the target. The second step is to assemble a design team that will really respect acoustics priorities. We have found that the owner’s functional priorities (including acoustics) are best maintained when the architect, theatre consultant, acoustician and cost consultant are all retained separately by the owner. A collaborative team is essential, and if the members of the team are respectful of each other’s interests, the project can move smoothly toward a design that has acoustic excellence at its core. The third step is to know what you want to achieve – what qualities of sound for what types of event. The acoustician should be able to comprehend and communicate the goals, and should be able to ‘hear’ the sound that is intended, much as a good architect can ‘see’ the finished building in their mind’s eye.
With these as a starting point, an acoustician with technical skill, design talent and consulting expertise will guide the architect and theatre planner toward a design that promotes good sound for the particular uses. In this highly technological era, live listening preference has been influenced by recorded and broadcast sound. Ironically, the sound picked up by an overhead microphone, or many microphones, is not a sound that can be heard at any one place in the hall. However, people have become familiar with the simultaneous clarity and resonance of classical music recordings, and now prefer these to the actual sound in an excellent hall. This shift in aspiration has found its way into theatre and concert hall designs of recent years, notably the Symphony Hall in Birmingham and the Sage Gateshead.
The shape of things to come
At its best, the architecture of a theatre can project the intelligibility of the spoken word. It can project the actors’ energy to the entire audience, conveying the emotion and drawing the performers and audience into the drama together. In thrust and in-the-round formats the challenge is to project in all directions, nearly simultaneously. The room design can play a supporting role by reflecting sound to the opposite side of the room, but the main onus is on the actors and director to generate presence, energy and sound in all directions. Unamplified instrumental music is most successful in spaces that gather the sound from all around the instruments and feed it in to the audience. Excellent rooms for music put the performers and audience in the same sound space, without a proscenium arch (as in traditional theatre) or any other architecture to separate the performers and audience. The shape of a concert hall is tremendously important because the geometry delivers the sound to the listeners, and the directions from which the sound arrives influence the quality, especially the sense of envelopment and connection to the performer. Theatre and music spaces have some important challenges in common. In live performance of either type smaller is better. In a smaller auditorium the sound can be stronger, and so an actor or musician can deliver greater acoustic impact. The further the walls and ceiling are from the performers and audience, the quieter the sound, and the less the impact of the fortissimo. The larger the audience, the more sound is absorbed. In a large hall, our philosophy is to preserve the sound energy as much as possible to maximise the sonic impact.
Sound examples
In 2006, the Four Seasons Centre opened in Toronto as the new home of the Canadian Opera Company (COC), to outstanding reviews for its acoustics. The commitment of General Director, the late Richard Bradshaw, was a key ingredient. The COC limited the seat count to 2,000 in the interest of acoustic excellence, and it was possible in this context to develop an orchestra pit and the size and shape of the proscenium to support both the strength of the singers and the warmth of the orchestra. Toronto is proud of its new opera house, and proud that quality did not have to cost the earth. Menuhin Hall at the Yehudi Menuhin School in Surrey has quickly gained a reputation for acoustic excellence. Two significant contributors to this success were the involvement of the headmaster and the chairman of the governors, and a brief that specified the best possible hall for students of strings and piano on a tight budget. The design included a very high ceiling, parallel walls, a wrap-around balcony and heavy timber finishes. As a result the room caresses the sound of the strings and helps the students project their individual personalities.