The phrase "to hear of" means to become aware or informed about something through word-of-mouth, rumor, news reports, etc. It can also mean to learn about something indirectly, rather than firsthand experience.
After all, I've never heard of someone NOT getting an interview opportunity because they sent a cover letter and they went above - and - beyond the requirements. (feather-communications.com)
I have to say... i never searched in my own country but never ever heard of something like it here! (chefambershea.com)
Some of these items I had never even heard of before so I was excited to get to try them out! (mamato5blessings.com)