Is there a way to write content that screen readers will ignore?

Question

I've just been working on a page which needs to be accessible to both sighted and visually impaired users. Some elements of the content, just by the nature of relating only to visual elements, simply do not apply to people using screen readers. For example, a link opens an audio-visual presentation in a new window, but due to circumstances beyond my control, the window is awkwardly resized, so there's a message saying that you should resize the window so you can see everything better. Obviously this is useless information to someone who can't see it anyway.

Is there an accepted way to make screen readers ignore some content?

Answer 1

Halfway through writing the question I remembered where to look.

CSS can do this:

<span class="dontRead">Screen readers shouldn't read this</span>

.dontRead {
    speak: none;
}

Answer 2

CSS has those aural properties, but as they aren't implemented anywhere they are completely useless.