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Nytt Operahus , Oslo, Norway

The glass dome is 70m in diameter and 35m high.

The acoustics of the new home of Den Norske Opera, the Norwegian national opera company, required a highly reverberant sound.

The acoustic designers had to strike a balance between the clarity of the sung words and the reverberation of orchestral music. Arup, working with local acoustic consultants Brekke Strand, provided an acoustic design for the main auditorium that achieved this balance.

As well as a main auditorium – the Store Sal – the 1,400-seat opera house contains a second, flexible format auditorium – the Lille Sal – and rehearsal spaces, as well as production and administrative facilities.

In addition to the acoustic design for the main auditorium, the Arup team brought its international opera house experience to bear on controlling noise from theatre equipment and other aspects of the venue’s acoustic design.

Arup's team worked closely with Oslo-based architect Snøhetta to make sure the opera house, which seems to rise from the Oslo Fjord like an iceberg, sounds as good as it looks.

Many older opera houses have short reverberation times which make sung words sound clear but the orchestra sound dry. However, modern opera houses tend to be more reverberant, to produce a more concert-like orchestral sound. This balance is what Arup’s client wanted for its Oslo home.

Adopting a novel auditorium cross-section – narrow at low level and wider above – helped to achieve the specified long reverberation time of at least 1.7 seconds. To arrive at this design, the Arup team used extensive computer and physical scale modelling of the auditorium and assessed design decisions using SoundLab, an innovative design tool developed by the firm.

SoundLab produces an accurate 3D sound experience that allows clients, users, architects and designers to listen to music in the proposed design and compare the sound quality against different world-class auditoria. It even gives the option of listening from different seats in the virtual auditorium.

Raj Patel discusses how the SoundLab is used to listen to performing arts spaces before they are built.