Alt Text For Fractions

I need to create a font of nut fractions with our own alt text. So, 1/2 would be read as “one half” by a screen reader, rather than “one slash two”. Or 1/4 as “one fourth”. How do I set this up in Glyphs?

Thank you!

oneoverfour

I’m not sure if screen readers apply opentype features. I suspect that they only look at the underlying characters. In that case, you can’t do anything from within the font.
There are some fractions encoded in Unicode. If those are used in the text, the screen reader might pick it up.