Why are websites trying to talk at me?

I examined that Dell link and speech synthesis is used in the "Virtual Assistant" on-page chat widget. There's a feature check to see if it's available so it shouldn't trigger the way it does for you, that may be a browser issue.

a lot of that may be TTS accessibility features.I know Ubuntu, among others, used to ship Firefox without modules it defaulted into, so it would complain harmlessly and bring up an annoying pop-up-blocked style modal when the TTS module/engine was missing.(they may still do this, but i'm not up to date.)

Maybe nobody else was listening?