Mario Illien says it is possible tweaks to the current generation of turbo V6 cars can produce a louder sound for Formula One.
The most controversial aspect of the new 'power unit' regulations, introduced last year, is their mild tone in comparison to the screaming V8 and V10s of the past.
Bernie Ecclestone is still pushing hard for changes, and while some solutions were studied and trialled in 2014, the sport will enter a second season in 2015 with the same quieter sound.
But Mario Illien, the famous F1 engine designer who is now working with Renault and Red Bull, has told Germany's Auto Motor und Sport that there are some possible solutions that could make the basic V6 layout louder.
Could be louder, easily
He said the biggest problem is the way the engines' 'wastegate' is currently laid out.
"It does not blow into the atmosphere, but into the exhaust, which is very long and quite thick and the sound is lost," Illien said.
He said if another valve exits separately, "the sound that the engine makes would go directly to the outside and you'd hear it a lot better", Illien predicted.
He cautioned, however, that his solution would only produce more noise in certain 'phases' of the power unit operation, such as when the battery charge is full.
"In the race, the benefit would be less," he admitted.
Wastegate positioning mandated by FIA
Illien also said the current regulations prescribe the position of the wastegate, speculating: "The FIA was probably concerned it would (otherwise) be used for some aerodynamic tricks".
He also said a shorter exhaust would help, while the typical turbo whistle would be louder in F1 if a bi-turbo was introduced.
And Illien said that if the current maximum fuel-flow rate was increased, the sound of the engine would also be turned up.