A caller may not use or connect to a telephone line an automatic dialing-announcing device or deliver a prerecorded or synthesized voice message to a subscriber unless the subscriber has knowingly requested, consented to, permitted, or authorized receipt of the message or the message is immediately preceded by a live operator who obtains the subscriber’s consent before the message is delivered. This section and section 51-28-05 do not apply to a message from a public safety agency notifying a person of an emergency; a message from a school district to a student, a parent, or an employee; a message to a subscriber with whom the caller has a current business relationship; or a message advising an employee of a work schedule.