You are a college professor. They are college students. In your syllabus, declare that only four-function calculators will be allowed during exams, and that you will be happy to provide said devices. Disallow all other electronic devices to be visible during an exam. If they took notes on a laptop, they should print them out before the exam.
This doesn't need to be a conversation about Faraday cages and the legality of blocking wireless signals. You are not expected to babysit your students--both you and they will enjoy being treated like adults, having been given clear guidelines and expectations at the start of the semester. Your efforts to accommodate your students are thoughtful and speak of good intentions, but there's no reason why the notes of a student for whom English is not a primary language cannot include a description of a difficult concept in their native language--especially if the potential need for that kind of information is called out in your syllabus.
Good luck, though. I mean it.