An estimated 2.3 percent of the U.S. population—7.3 million people—have some form of visual disability ranging from impaired vision to total blindness. In order to enjoy access to websites and other digital media, many people with visual impairments rely on assistive technologies such as braille displays and screen readers
We’ve discussed screen readers in previous articles here at the Bureau of Internet Accessibility. However, with the June release of the updated Web Content Accessibility Guidelines, WCAG 2.1, it’s the perfect time to look back on what web developers should already know about screen readers, and what you should know moving forward.
What Are Screen Readers?
A “screen reader” is a software application that converts the text displayed on a computer screen into synthesized speech. Text-to-speech capabilities are a vital component of AI assistants such as Apple’s Siri and Amazon’s Alexa, which “talk” with users by converting their replies into digital speech. Screen readers are a specific use case of text-to-speech technology that improve accessibility for people with visual disabilities.
These days the market offers many options for screen readers. Some are intended for use with different operating systems and applications; some are free and open source; others are commercial software. A few of the most popular screen readers are JAWS, NVDA, ZoomText for Windows and VoiceOver for Apple products.
How Do Screen Readers Work?
Screen readers are able to look for and process any kind of text that is displayed on the screen of a computer or mobile device, including website content, icon labels, documents, spreadsheets, file menus and more.
Once it identifies this text, the screen reader speaks it out loud at the user’s request, pausing at punctuation such as periods, commas, and exclamation marks. The software also reads the title of web pages and the alternative text captions for any images on the page.
Meanwhile, the user can choose to repeat a given word or passage, search for a given string of characters, or adjust settings such as the speed and volume of the speech.
Screen Readers and the WCAG
The Web Content Accessibility Guidelines are the most widely recognized web accessibility standard. The latest version, WCAG 2.1, added a variety of new guidelines to the existing standard. Several relate to screen reader use:
- Non-textual content should have a “text alternative.” For example, images should have descriptive embedded captions so that screen readers can inform users with visual disabilities about the contents of the image.
- The human language of each web page can be “programmatically determined” by a software application. This is important so that the screen reader knows the correct pronunciation for the words on the page.
- The human language of each passage or phrase on the web page can be programmatically determined. If a web page contains words, phrases, or texts in a foreign language, then the page must indicate this to the screen reader so that it pronounces these parts in the correct language.
What Web Developers Should Know About Screen Readers
- To meet WCAG guideline 1.1, developers should use the alt attribute in HTML tags. For example, an image of pancakes may have alternative text such as: <img src="pancakes.jpg" alt="A stack of pancakes">.
- To meet WCAG guidelines 3.1.1 and 3.1.2, developers should use the lang attribute in HTML tags. For example, if the main language of a page is English, the page’s HTML file should start with the tag <html lang="en">.
By accommodating screen readers, you’ll go a long way in making your website more accessible to millions of people with a visual disability. For more information about how you can comply with accessibility standards, follow the BoIA blog for the latest news and updates, or contact us for a free consultation.