A person who consistently feels the need to hear himself or herself talk, usually burdening their personal information on others. Not to be confused with "attention junky."
A hear-me hoar can be recognized for his/her unnecessary outbursts, causing a conversation to revolve around him/her.
Here I am, trying to give a presentation to my business associates, when Micky-G turns into a hear-me hoar and tells everyone how his daughter farted in her bath water.