Article

How Screen Readers Read Content

by WebAIM

This section presents a list of ways that screen readers read and pronounce content. It is not an exhaustive list, by any means, but it will help developers understand screen readers a little better. Most developers will not need or be interested in more information than what is presented here, but those who are interested should consider either buying full versions of the various screen readers or else downloading trial versions.

• Screen readers pause for periods, semi-colons, commas, question marks, and explanation points.
• Screen readers generally pause at the end of paragraphs.
• Screen readers try to pronounce acronyms and nonsensical words if they have sufficient vowels/consonants to be pronounceable; otherwise, they spell out the letters. For example, NASA is pronounced as a word, whereas NSF is pronounced as "N. S. F." The acronym URL is pronounced "earl," even though most humans say "U. R. L." The acronym SQL is not pronounced "sequel" by screen readers even though some humans pronounce it that way; screen readers say "S. Q. L."
• Screen reader users can pause if they didn´t understand a word, and go back to listen to it; they can even have the screen reader read words letter by letter. When reading words letter by letter, JAWS distinguishes between upper case and lower case letters by shouting/emphasizing the upper case letters.
• Screen readers read letters out loud as you type them, but say "star" or "asterisk" for password fields.
• Screen readers announce the page title (the <title> attribute in the HTML markup).
• Screen readers will read the alt text of images, if alt text is present. JAWS precedes the alt text with the word "graphic." If the image is a link, JAWS precedes the alt text with "graphic link."
• Screen readers ignore images without alt text and say nothing, but users can set their preferences to read the file name.
• If the image without alt text is a link, screen readers will generally read the link destination (the href attribute in the HTML markup).
• Earlier versions of JAWS do not pause after reading link text, but JAWS 6 does pause, helping listeners audibly distinguish between the link text and the text after the link. When an image and text are included in the same link, there is no pause between them.
• Screen readers read the alt text for image map hot spots, but not necessarily in the visual location where the image occurs. In terms of HTML validity, the hot spots (<area> tags) do not have to be adjacent to the image in the HTML markup (the <img> tag), but developers should not separate them in the markup. If the image and its hot spots are separated in the markup, JAWS will read the alt text for the hot spots out of order with the rest of the document.
• Screen readers can announce headings. JAWS, for example, precedes <h1> headings with "heading level 1."
• Some screen readers announce the number of links on a page as soon as the page finishes loading in the browser.
• JAWS says "same page link" if the link destination is on the same page as the link itself.
• Screen readers in table navigation mode (users have to activate this mode) inform the user how many rows and columns are in a table.
• Users can navigate in any direction from cell to cell in table navigation mode. If the table is marked up correctly, the screen reader will read the column and/or row heading as the user enters each new cell.
• Screen readers inform users when they have entered into a form. Users have the option to enter form navigation mode.
• Recent versions of screen readers can switch languages on the fly if a page or part of a page is marked as a different language. For example, if a Spanish phrase appears in an English page, the screen reader can switch to Spanish pronunciation if the phrase is marked as a Spanish phrase: <span lang="es">Viva la patria</span>.
• Most screen readers pronounce words correctly in almost every instance, but occasionally they misinterpret the difference between homographs (words that are spelled the same but which have different meanings and/or pronunciation). For example, the word read can be pronounced "reed" or "red," depending on the context: "I must read the newspaper " vs. "I have read the newspaper." A sentence such as "I read the newspaper every day" is actually ambiguous to all readers—humans and screen readers alike. It could mean that the writer reads the newspaper every day or that the writer used to read the newspaper every day. Depending on what the writer meant to say, the word read in that sentence could be pronounced either "reed" or "red." The word content is another example: "I feel content " (meaning happy, with the emphasis on the second syllable [con-TENT]) vs. "Skip to main content" (meaning the subject matter, with the emphasis on the fist syllable [CON-tent]).
• Screen readers read most punctuation by default, such as parentheses, dashes, asterisks, and so on, but not all screen readers choose to read the same pieces of punctuation. Some do not read asterisks by default, for example. Periods, commas, and colons are usually not read out loud, but screen readers generally pause after each. Users can set their preferences so that screen readers read every punctuation mark and character.

posted on Jun 6, 2007

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