Audiobook sales rose 20% in the US last year, according to the Audio Publishers Association (APA).
According to an annual survey of industry trends by the APA, sales of audiobooks reached $1.78bn (£1.22bn) last year, up by one fifth in 2014. By volume, unit sales leapt up even further by 24% year-on-year, according to Publishers Weekly.
The sales rise coincides with increases to publishers' output, with audiobook production soaring 37% to 35,574 titles coming from the 20 US publishers taking part in the APA’s survey.
Altogether sales of adult audiobooks accounted for 90% of overall audiobook sales, with fiction the most popular category.
In the UK, audiobook sales rose by 27% in 2015, according to Nielsen Book UK, The Bookseller has previously reported, with the format now accounting for 3% of book purchases by volume of the book market.