The Sydney Opera House will undergo a multi-million-dollar overhaul, with an emphasis on improving its acoustics, once described as worse than an aircraft hangar, officials said last week.

The Aus$247 million ($190 million) revamp is the biggest since Australia’s most recognizable building opened in 1973 and includes other upgrades to the main concert hall and the foyer, along with a new function center.

Describing the landmark as a “symbol of modern Australia”, New South Wales state deputy Premier Troy Grant said the renovations were necessary to help the Opera House – the country’s busiest performing arts center – meet demand.

The refurbishments in the concert hall will involve the installation of a new acoustic ceiling, specially designed acoustic reflectors, automated draping, and a 3D surround-sound system.

The second-largest performance space, the Joan Sutherland Theatre, is also being redeveloped.

There has long been criticism of the acoustics of the concert hall, which is located inside the largest roof sail of the Opera House.

US actor John Malkovich in 2014 said the acoustics were so hideous they “would do an airplane hangar a disservice”.

“It’s lovely to drive by on a motor boat and it has a very nice crew, and very capable, but the acoustics are hideous,” the American star told a local newspaper then.

In 1999, Sydney Symphony Orchestra chief conductor Edo de Waart threatened to boycott the venue during the 2000 Olympics, calling its acoustic reflectors “a joke”.

“The doughnuts (clear, circular reflectors above the platform) are a joke. They might as well be toilet seats. They do nothing whatsoever,” de Waart told the ABC then about his frustrations, which were shared by his predecessors.

“It’s very frustrating. You get no help from this hall. It actually takes away from the sound the orchestra makes.”

Danish architect Jorn Utzon began work on the harborside structure in 1957 but quit the project in 1966 during construction following a storm of controversy over budget blow-outs and his artistic vision.

Changes to the interior design after Utzon departed left the building – which was placed on the UNESCO World Heritage list in 2007 – with acoustics criticized as inadequate for international opera standards.

Sydney Symphony Orchestra’s managing director Rory Jeffes said his musicians were excited about the improvements, adding they would deliver the “true ambitions” of the original creators.

The concert hall revamp is expected to start in mid-2019 and last for 18 months.