Is there a legal requirement to have an audio engineer title on a business card? -

in addition to the above question, is it legal to use the term Audio engineer on a business card if you have no degree specifically stating engineer? for example, a person who designs audio for a living, can they list themselves as an audio engineer? where does the line blur / cross over?

Technically you can put anything you want on your business cards.It s up to you to draw the line at how much you d be lying to clients when you hand them the card.