The ‘Battle of the Sexes’ creative team went all out to replicate sound effects from the 1970s tennis match in the movie.
The biopic, which is based on the 1973 sporting event between Billie Jean King (Emma Stone) and Bobby Riggs (Steve Carrell), saw sound designer, editor and mixer Ai-Ling Lee purchase the old-fashioned wooden and aluminium tennis rackets with "gut material", which were used during the seventies, and record tennis hits made from the sporting equipment to ensure the competitive scenes were re-created as accurately as possible.
Speaking about the lengths she went to to ensure the production was as close to the iconic tournament as possible, Lee said: "I bought wood and aluminum rackets on eBay, almost like the ones used in the film, and recorded tennis hits with them. The old rackets are heavier compared to the graphite rackets nowadays, and the wood has a certain resonance. Even the strings in the rackets, I got them with gut material, which is closer to what they used back then.
"All these details contribute to slightly different-sounding tennis hits than the contemporary ones.
"And I varied the tennis hits with slices and lobs so you hear the soft and hard hits that are part of the strategy in the game."
And the creative mastermind – who was nominated for the Best Sound and Academy Award for Best Sound Mixing for ‘La La Land’ at the 89th Academy Awards – decided to make Steve’s footsteps "heavier" as he grew "more tired" during the competition.
She added: "I also made Bobby Riggs’ feet stomp heavier as he got more tired."
Lee has revealed she and fellow members on the sound team of the Fox Searchlight movie, Mildred Iatrou Morgan, Ron Bartlett and Doug Hemphill, found the ABC broadcast of the tournament , which they tuned into , to learn more about the noises made during the game.
And Lee told The Hollywood Reporter magazine that after extensive research they noticed female viewers cheered for King, while the majority of men supported Riggs.