An FIA source told Germany's Auto Motor und Sport: "There is nothing in the promoter contracts prescribing a minimal decibel level."
The source also scoffed at Walker's suggestion the issue drove fans away from Albert Park.
"Those who did not come have not yet heard the engines," he exclaimed.
However, it remains a possibility the new low volume of F1 could have contractual consequences.
Sepang circuit boss Razlan Razali told the local New Straits Times newspaper that the engines will surely "affect the atmosphere of the race".
"So we'll want to see more of how this issue develops," he added. Malaysia's F1 contract expires after the 2015 race.
Reigning world champion Sebastian Vettel turned up the volume even more when on Friday he crassly described the sound of the 2014 cars as "shit".
"And batteries should be where they belong, in a mobile phone," he is quoted by the German news agency SID.
Red Bull might at least have a solution to the noise problem.
"If we change the turbo blades, it will sound better," team director Dr Helmut Marko said.
Williams' Felipe Massa, however, thinks F1 simply needs to get used to its new guise -- again.
"Years ago, when they made the decision to change the engine (for 2014), the first thing everyone said was that the sound will be different," he is quoted by Brazil's Globo.
"Now it's too late. They can try anything, but it's impossible to make them sound like a V8.
"Instead they thought it was the right direction to go with the new technology, so that's how things are now," added Massa.