Some devices allowed, but kept to minimum usage
Having cell phones in the workplace may not be bad, depending on the employer. Allowing calls to a minimum, in case the family member need to contact you.
Texting is also allowed in some companies.
Wearing headphones in the place of hearing protection is not permissable. The employee cannot hear with the music playing loud and cannot hear past the loud machinery. If they cannot hear you, then how are they to hear the machinery starting.
Computers allowed ONLY if being used for company business.