Until recently they were dismissed by serious book lovers, but the rise of podcasting and mobile phones has created a huge demand for audiobooks.

At the Frankfurt book fair, a chunk of Exhibit Hall three contains no books at all. Instead the area is dedicated to audiobooks, podcasting and the companies making those mediums thrive.

This year's event has become a key date in the calendar for publishers and book houses across Europe, with a keynote speech by the 2018 Nobel Prize for Literature winner, Olga Tokarczuk. 

Many attendees, veterans of the industry, cite the convenience of using ears over eyes.

"I know people, they like to do it because they can do other things and listen. For their travels. A long time in the car, it can be boring to do nothing," said Berte Wulf-Hepperson, a librarian from the small town of Rheinbach.

But for many in today's tech-driven world, audio has simply become the only way to "read."

Zebralution, a German firm specializing in audio book marketing says publishers are starting to get the message.

They have understood there's a young generation coming up who have never bought a CD, never bought a download," said Zebralution CEO Kurt Theilen. "Their world is Spotify and Netflix and all the others."

The trend is rising across Europe. The UK Publishers Association said sales of audiobooks rose 43 percent last year, while print edition sales lost ground. 

In Sweden, Julian Lundsgaard, the CEO of Swann Studio, and audiobook production and distribution company, said around half of literature is now consumed in audiobook form.

In the US, the Audio Publishers Association said revenue from sales hit $94 million in 2018, up almost a quarter on the previous year.  

However, some attending said they will never be able to give up the rustle of the page and the smell of fresh ink.

"My friend and I actually only started to listen to [an audiobook] here," said Lene Kumpf, a seller of antique books. "But we didn't like it, so we stopped after 30 seconds."

Nonetheless, the profile of the audiobook is on the rise. Adaptations of highly anticipated new releases frequently boast voice overs by famous actors.

Ann Dowd, who starred as Aunt Lydia in the recent television adaptation of The Handmaid's Tale features on Amazon's audiobook version of Margaret Atwood's Booker prize winning sequel, The Testaments. on the company's Audible platform.   

In today's busy world, where many would still like to say they have found time to "read" weighty classics such as Crime and Punishment or Anna Karenina, audiobook sales appear to have some way to go.