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There are a range of different formats - each with different accessibility credentials. Readers might prefer familiar formats (like Word), or formats that offer more portability across devices (like html or PDF). For readers with disabilities the flexibility of the format is very important so EPUB is attractive but no single format guarantees accessibility.


DAISY (Digital Accessible Information SYstem) is a specialised standard format for delivering accessible text for the print impaired. It is essentially an XML-based ebook format that can incorporate both text and audio. It usually includes navigation features not commonly found in standard audiobooks. Most commonly, these navigation features include full-text searching and page navigation. They may also include footnotes, indexes, and tables of contents. 

DAISY books may include:

  • both text and audio: These titles permit full-text searching, and are the ones most commonly produced by NNELS. These titles use synthetic narration and can be identified by the narrator beginning with the word "Apple", as in "Apple Alex" or "Apple Samantha", or "Scansoft", as in "Scansoft Daniel". Some software or devices ignore the pre-made audio in favour of built-in text-to-speech features.
  • audio only: Navigation is typically limited to chapter and section navigation and there is no full-text searching. These titles are produced by NNELS using live narration.
  • text only: The software or device will use text-to-speech capabilities. Text-only DAISY is rare in the NNELS collection and is usually identified as such on the title details page.

NNELS produces two kinds of DAISY books: DAISY 2.02 and DAISY 3 (full-text and audio). DAISY 2.02 is an older standard and these books work with older DAISY players. DAISY 3 books are most likely to work with newer devices.

DAISY can be burned to CDs (see our Burn a DAISY disc tutorial) and unlike traditional audiobooks which can be on 10 or more CDs, the contents of DAISY audiobooks usually fit onto a single CD (so long as they are burned as "data" rather than "audio" or "music"), making them easy to handle by people who can't read the CD numbers of traditional audiobooks. While we do not produce CDs, please speak with your public library if you require titles in this format.

DAISY books can also be played on almost any computer or device using apps or software, and transferred between devices using USB sticks and SD cards

MP3 Audio

Many live narration audiobooks in NNELS are in MP3 format, and all MP3 audiobooks in NNELS are produced using live narration. Most MP3 audiobooks will also contain one or more playlist files to ensure the tracks play in the correct order. They do not contain special navigation features or permit full-text searching.

MP3 audiobooks are compatible with almost any computer or device. They can also be played on an MP3 player, or any other device that can play audio files.

MP3 can also be burned onto a CD in the same way a DAISY book can, and DAISY players can play an MP3 audiobook.

Most newer CD players will play MP3 audiobooks, which will usually fit onto a single CD so long as they are burned as "data" CDs. Books that are larger than 700 MB will require more than one CD.

Older CD players may not work with MP3 audiobooks, and for these players, burn CDs as "audio" instead of "data". When creating "audio" CDs, the audiobook will likely not fit onto a single disc unless it is less than 80 minutes long. The number of CDs required is determined by the length of each track, and most blank CDs can accomodate 80 minutes of playing time. Therefore, these audiobooks need to be burned in batches of 80-minutes or less. Please call or write to us if you have questions (that's what we're here for).

All DAISY titles in NNELS contain MP3 audio files, so it is possible to create MP3 or traditional audiobooks from DAISY books. Please see the forum post on providing MP3 when only DAISY is available for more information.


Electronic text or e-text, may be found in a variety of formats, including RTF, DOC, DOCX, and HTML.

NNELS often publishes titles in DOCX format Word is a popular format with users, as it is familiar, it has 500% magnification with reflow, can change foreground and background colours easily and is amenable to text to speechThat said, if you need a book that is not in a format you can use, please let us know so we can create it for you and add it to our collection.

All synthetic-narration DAISY books in NNELS contain a full-text version of the book, typically the "contents.html" file. To customize the display, this HTML file can be opened with word processing programs or browsers and manipulated from there (e.g. change font, size, spacing, margins, etc.).


EPUB is increasingly seen as a format that is suitable for both commercial exploitation and meeting accessibility needs. In its latest upgrade, EPUB 3 has embraced all accessibility features present in the DAISY standard. A reflowable EPUB with table of contents (TOC) and image descriptions can be read on a range of devices with text-to-speech and magnification if required by the user. EPUB is a HTML-based, platform-independent ebook format, which is highly adaptable and can offer the greatest accessibility to readers from a mainstream product. 

EPUB 2 and EPUB 3 are available for some titles, usually when contributed by, or purchased from, a publisher. 

NNELS produces EPUB 3 with audio (or "media overlays"). These books contain sound files so that the text includes synchronized audio narration (synthetic narration only), similar to DAISY books. For systems that do not support the audio overlays, the EPUB files with media overlays work as regular EPUB books and will be readable with any software that supports EPUB. 

EPUB format can be read by almost all reading software, such as: newer DAISY players, Kurzweil, Read and Write Gold, Kobo eReader, Blackberry Playbook, Apple's iBooks app, Barnes and Noble Nook, Sony Reader, Adobe Digital Editions. The only notable device lacking integrated support for the EPUB format is the Amazon Kindle, although there has recently been speculation that the Kindle will soon support this format. Because an EPUB is HTML-based, screenreader users can easily access a structured web document through a browser; however, different browsers have different accessibilty features.

For analysis of reading systems and how well they support EPUB 3 with Media Overlays, please see the EPUBTest website. We use the latest version of Adobe Digital Editions, which works well.


PDF is typically requested when a reader would like the digital copy to look exactly like the print book. 

PDF is still a common file format for publishing, and most of the PDF files in NNELS come directly from publishers. The level of accessibility for PDFs provided in NNELS varies. Publisher-provided PDF files may not always work well with assistive technology due to fewer accessibility options with text reflow and navigation often being absent.

Our PDF files should always be text-readable, allowing text-to-speech reading, but it is common for us to change PDF files to a different format at the request of a reader.

Other Formats

NNELS can provide e-text in RTF or any other e-text format to be used with refreshable Braille devices, or Braillers.

We encourage Large Print users to make use of our e-text (where text can be enlarged).

You may find BRF (Braille Ready File) and other formats in the NNELS collection that we have acquired but generally do not produce. BRF is a standard format that renders contracted UEB Braille code onto a Braille display.

If you need a specific format not listed, or need a format with certain specifications and it is not already available, please request it and we will do what we can.