I guess it depends on the library. In our locale, one is adamant even about breathing to loudly, another is OK with a little conversation but asks that cell calls be taken outside. I was embarrassed one day, out in the hall at another library, to be asked to keep it down as I explained to someone about the use of the computer. I expect someone had complained. Quite reasonable, I felt. We had being going on a while as she was so excited about watching me use my laptop and wanted to know everything. So each seems top be different - like the people who work in them, and use them.