bleatchild
The type of person who whines and whinges away very loudly in public about something that is utterly irrelevant to everybody in the vicinity. The person whose type of loud whiny voice you just cannot escape from - particularly if you trying to enjoy a meal in a nice restaurant, or if you are on a train journey, or somewhere quiet just trying to read a good book. The 'bleatchild' arrives and his or her voice then infects everyone's personal space for yards and yards around.
"That irritating bleatchild sitting four tables away from us is really going to spoil my meal - are you okay if we just walk out now before ordering? I just can't stand that type of voice!"