From text to speech for pleasure

Audiobooks: bringing literary works to all audiences

By Philippa Martin-King

Written works have been central to the culture of many civilizations for centuries. However, their main vehicle, print, has meant that they have not been accessible to all, the visually-impaired in particular. Audiobooks, which first appeared in the early 1930s on long-playing records, aimed initially at remedying this. Audiobooks are now reaching an ever wider audience thanks to the emergence of digital platforms and distribution channels. A recent IEC International Standard defines the file format requirements and structures for digital audiobook media.

Audiobooks are proving ever more popular Audiobooks are proving ever more popular

Not that new

While print form has been most commonly encountered, some works were recorded in very limited numbers as audio documents on wax cylinders as far back as the early 20th century. Audiobooks as such first appeared in the early 1930s, on LPs (long-playing records) initially aimed at the visually-impaired. In 1933 the American Foundation for the Blind developed the first long-playing record and player to provide books in audio format to people of all ages who had disabilities that prevented them from reading standard print books.

Beyond the visually impaired

Audiobooks on LPs later extended beyond the world of the visually-impaired to reach schools and libraries. The invention and widespread adoption of the compact audio cassette, in the mid to late 1960s, provided an ideal platform for audiobooks to reach the general public. Cassettes were tougher and easier to use than LPs and could be played while on the move and in cars. This led to the growing popularity of audiobooks, which now reach a wide public, young and adults alike.

Surveys show that US audiobook listeners are well-educated and avid readers. On average they read 15 print books a year compared with only 6 for people who don’t listen to audiobooks. Contrary to common perception, audiobooks are also drawing in young adults in large numbers; almost a quarter of listeners are between 18 and 24.

However, if audiobooks are now available for all audiences, the market is in no way global. Audiobooks are very popular in the US, where more than 6 200 were published in 2010 and where the total value of the industry in 2009 was estimated at USD 900 million, with sales of 20 million audiobooks that year. Audiobooks are also popular in the United Kingdom, Germany, Poland and the Nordic countries (more than 10% of the overall book market), but are virtually non-existent in French-speaking countries (accounting for just 0,7% of France’s book market in 2008, although the figure is growing) .

Evolving formats bring the end of the physical medium

The introduction of digital audio and of its initial storage mechanism, the CD (compact disc), didn’t lead to the immediate demise of the compact cassette as the most popular platform for audiobooks. CDs may have superior audio quality, but compact cassettes remain in the same position when stopped, making it possible to resume listening later from the same point. Audiobooks on CD only became more popular after CD players widely replaced their audio cassette counterparts, in particular in cars where most audiobook listening is done.

The migration of digital audio files from a set physical medium (CD) to online electronic distribution had a momentous impact for the music industry and for audiobooks as well. The files are now available in a number of distinctive formats that can be played on different devices. In the biggest market, downloads are quickly catching up with CDs, which until now have constituted the primary source of audiobooks, with compact cassettes now representing only approximately 1% of total sales .

The need for standards

The need to define the audiobook electronic file format structure to ensure compatibility with music industry and multimedia standards, as well as how to present and navigate an audiobook effectively, led TA (Technical Area) 10: Multimedia e-publishing and e-book technologies, of TC (technical committee) 100: Audio, video and multimedia systems and equipment, to prepare an International Standard.

IEC 62571, Digital audiobook file format and player requirements, was published in early 2011. It "defines requirements and provides recommendations to publishers, software developers, content providers, and hardware manufacturers for the data structure, usability requirements, playback systems and delivery systems for audiobooks in digital file format."

Broad definition, complex structure

IEC 62571 describes the term audiobook "as any audio file or collection of audio files of primarily spoken word content that are played in a linear or specified order. Therefore, spoken word audio with occasional music, a narration of newspaper articles, or other similar spoken word audio is assimilated to audiobooks in this standard."

As digital audiobooks and their associated characteristics predate publication of this International Standard, TA 10 presents IEC 62571 as "a compilation standard that straddles early binary architectures represented by earlier versions of ANSI (American National Standards Institute) CEA-2003 [standard], and newer XML architectures."

The standard defines the audiobook player and file format structure requirements and specifications. It also describes and lists extensively the complex characteristics of tags, metadata and other information that apply to audiobooks and are required to describe the content, author, narrator, to give copyright and other information, and to navigate through the playlist.

"Creating the best listening experience"

If e-books and e-readers have become a global phenomenon, the lesser known audiobooks are also experiencing healthy growth in certain markets. TA 10 aims at contributing to this success. Its stated goal in preparing IEC 62571 was "to create a broad, extensible standard for audiobook publishers, audiobook device manufacturers, and audiobook software developers in order to create the best listening experience for the audiobook consumer."

Audiobooks are proving ever more popular Audiobooks are proving ever more popular
The first audiobooks were recorded on LPs The first audiobooks were recorded on LPs
Analogue to digital: listening to audiobooks anywhere with an MP3 player (Photo: Sandisk). Analogue to digital: listening to audiobooks anywhere with an MP3 player (Photo: Sandisk).