I don't think Shelob ever spoke in the book (though Gollum appeared to have some alliance with her, so maybe he at least figured out how to communicate with her), and I'm not sure if Ungoliant ever spoke to anyone but possibly Morgoth (who was a Valar and had near divine abilities, perhaps second only to Eru and maybe Manwe). The only one that I can recall hearing and understanding the spiders talk is Bilbo. Of note of interest is that not all the North Eastern creatures could be understandable to your average joe that knew just the Common Speech, as, though the language of the Wargs was translated for us, it appears that nobody in the company (maybe save Gandalf), understood exactly what they were saying. However, Bilbo DOES understand the spider children of Shelob. However, all of the time he is hearing and even talking to and taunting them, I believe, he is WEARING the Ring. (Could be wrong as I cannot recall every single word in that chapter.) So it's possible that the Ring gave him the ability to understand and talk to the Spiders of Mirkwood.