Assistive Technology Series: Screen Readers

One important key factor to having an accessible web page or document is for users that use a screen reading software. According to the United States Census Bureau there is approximately 8.1 million people that have difficulty seeing. Accessible websites and documents go beyond colors, text, and images. A screen reader is a generic term for a program that assists people who are blind or have low vision use a computer. A screen reader will do as it says, it will read the content on a page and speak the content to the user.

The Basics

When it comes down to it, a screen reading software is loaded on to a computer and works with the Operating System to provide information about icons, menus, dialogue boxes, files and folders. Anything you can think of that a computer does, will provide feedback to the user who is blind or has low vision through speech or Braille. The technical term that a screen reader will use is ‘Text-To-Speech (TTS) engine’. The Text-To-Speech engine will translate any on-screen information from the computer into speech that can be heard through either headphones or speakers. Many newer computers come with TTS built into their Operating Systems already. It also comes packaged with a purchased screen reading software. Many have the option of customizing the voice and speed of reading to the user’s preference.

Screen readers also have the capability to exchange information from the computer and turn it into Braille. Braille is a system of touch reading and writing in which raised dots represent the letters of the alphabet. A screen reading software will need an external hardware device, known as a refreshable Braille display, to present the digital information to the blind user. A typical refreshable Braille display contains one or more rows of cells that can be formed into the shape of a Braille character. As you navigate through information on a computer the Braille characters on the display change. This is most often used in conjunction with the Text-To-Speech.

The Screen Reader is Installed, Now what?...

It is common for a computer-user who uses a screen reader to not use a mouse. Each individual screen reader is a little different. They use a wide variety of keyboard commands in order to carry out different tasks. For example, when a user would like to read only a specific part of a document or when navigating the menu on a website. Other tasks include opening a specific file that lives in a folder on the desktop or managing a library of digital music. It’s important to note that most Operating Systems come with their own set of keyboard commands to allow a user that only uses a keyboard to navigate a computer with ease.

The screen reader will default to using the primary language of the operating system installed on the computer. Most screen readers will also support a few common languages. As part of having an accessible document, it is important to label the primary language of your document when you save it. This makes it easier for a screen reader to pick up on.

When a screen reader drives up on a graphic or image with alternative text, it will identify it as a graphic first, and then relay the text description through TTS or Braille. A well-structured web page that contains headings, lists, paragraphs, and alternative text will make the job of the screen reader much easier. A screen reader will look at the code of a web page and make certain key commands available. For example, if a table appears on a web page, the screen reader will look for column and row headings and relay that information to the user. There is also a set of quick navigation keys specific to the screen reader for moving through a web page. For instance, a key command that will help a user move through lists, headings, images, and links at a faster pace.

Each screen reader uses a different series of commands, so most people will tend to choose a screen reader and stick with it, as the task of learning many new keyboard commands can be a challenge.