bq. This is not a line of thinking I wish to see furthered in any modern web builds.
I agree it isn’t ideal, but offscreen positioning is the only reliable way to visually hide content without making it inaccessible to assistive technologies. Perhaps that will change in the future, but it’s what works best now.
bq. When “˜accessibly-hidden’ is added via JQuery is it changing the state of display: none and adding text-indent and/or positioning CSS to achieve the same effect? Why is the slideDown(0) in the hiding portion of the code?
The “accessibly-hidden” @class@ simply hides the content by positioning it off-screen. When jQuery applies that @class@, the content is hidden from view and the @slideUp@ (which originally hid the content by adjusting the element’s height before setting @display:none@) can be reversed (thereby removing the @display:none@ CSS property jQuery had applied). It’s kind of like sleight of hand.
The steps are reversed when a user goes to expand the element again.
bq. Excuse my ignorance but are these software readers or actual devices? if it’s hardware, are there emulators available?
In some cases, they are software (such as screen readers like the excellent NVDA catchmyfame mentioned). In other cases, they are a hardware/software combination (e.g. a braille printer or touch-feedback device). I am not aware of emulators for hardware-based assistive technologies. I don’t think they’re often needed; most hardware-based assistive tech has a direct equivalency to more common input devices (e.g. mouse, keyboard, etc.) and output devices (e.g. printers, speakers, etc.).
Would I program visual effects for blind people?