The ariaAtomic property of the Element interface reflects the value of the aria-atomic attribute, which indicates whether assistive technologies will present all, or only parts of, the changed region based on the change notifications defined by the aria-relevant attribute.

A string with one of the following values:

"false"

Assistive technologies will present only the changed node or nodes.

"true"

Assistive technologies will present the entire changed region as a whole, including the author-defined label if one exists.

In this example the aria-atomic attribute on the element with an ID of "clock" is set to "true". Using ariaAtomic we update the value to "false".

<div id="clock" role="timer" aria-live="polite" aria-atomic="true"></div>

let el = document.getElementById("clock");
console.log(el.ariaAtomic); // true
el.ariaAtomic = "false";
console.log(el.ariaAtomic); // false