A person needs to hear a new information at least three times before it registers into his/her mind for immediate recollection.
This has been taught over and over again to us and you can test it by saying aloud a new name you come across three times conciously.
A sharp individual can catch it the first time. Some people will never learn it by hearing it, and must see it (visual learners). Others learn through doing it themselves. People are wired differently, so one can't make a blanket statement about what will work and what won't.