The world of F1 will hear Mercedes' 'megaphone' exhaust for the first time early on Wednesday.

The first images of the metre-long, trumpet-like attachment have already emerged, and one of the first to see the volume-boosting device was Bild correspondent Nicola Pohl.

"It is extremely light, about 1.5 kilos," she said, claiming it is made of "mystery" materials. "Before the funnel end there is a small hole."

It will be fitted to Nico Rosberg's Mercedes when the car is fired up on Wednesday morning at the post-Spanish grand prix test.

Some are looking forward to hearing a 'loud' formula one car once again, following widespread criticism of the milder tone of this year's turbo V6 engines.

Others are not happy F1 is heading down the road of making its highly-sophisticated and 'green' new engines artificially loud.

"It's crazy to talk about making a formula one car louder," former McLaren and Ferrari driver Gerhard Berger told APA news agency.

"The whole discussion is just nonsense."

The governing FIA, however, is so serious it has engaged sound experts to work on the solution with F1's three engine makers Mercedes, Ferrari and Renault.

"The FIA have some acoustic consultants who have visited us and have had access to our existing dyno test results, including sound measurements," said Renault's Rob White.

But earlier, White's boss Jean-Michel Jalinier insisted F1 should not be ashamed of its more efficient - and therefore quieter - engine technology.

"You just have to move with the times," he argued, "and it is no longer the time for a V10 or V8 using 60 litres of fuel every 100 kilometres."

Some believe the more docile noise produced by a F1 car in 2014 is a tribute to its brand new and impressive technology.

"It (the 2014 'power unit') uses less energy," said White. "It does so more efficiently so there's less falling out of the back as noise.

"I don't sign up to the opinion they sound horrible. Instead, I feel there is a positive message that has kind of got drowned out."

White told the Daily Mail he is not closing his ears to the calls for more noise, but there are paddock rumblings that Mercedes' rivals are sceptical the 'megaphone' exhaust might add performance to the German team's already-dominant car.

"My short to medium term concern is we mustn't be put in a situation where we take a performance hit relative to our competitors, directly or indirectly as a result of this subject," he admitted.