Somebody doesn't neccessarily have to be a professional teacher or have a teaching degree to be able to transfer or pass on some kind of knowledge or experience. If your message, text or ad have something to be learned, that you might need to resort to a pedagogic voice.
According to a standard dictionary definiton, pedagocical is a term that relates to anything that is befitting a teacher or education. A parent has something education or pedagocic to tell his child a group of new workers at a company need to acquaint themselves to their working conditions, and there are numerous other situations that can benefit from a use of a pedagogic voice.
Of course, any audience that needs to hear an educational or instructional text or message can benefit from a pedagogic voice. As far as an age group is concerned, it can be a group of kindergarten children, students at any educational level, up, to a group of senior citizens that has to be accustomed to daily life at an advanced age. Practically any type of an audience that has to, or wants to listen to an educationa/instructional message/text will probably react more favorably if it hears it from a pedagogic voice.
A pedagogic voice is usually in the mid - range, highly articulate and pronounces its words clearly so that each can be fully understood. It speaks in mid-tempo and exudes knowledge and experience that makes the audience that listens to it believe in what the voice has to say. It sounds like a voice that the audience can trust is giving them the best possible information.