What is this symbol on my Blackberry Pearl?

I have a question about a symbol on my Blackberry Pearl 8130...?

• In the upper right hand corner there is what looks like a flag. It is blue on the bottom and black on the top with stars going diagonally down starting at the upper left hand corner down to the lower right. This only appears when I make or receive a phone call. I can't find my manual and I've searched over and over online for the answer and I can't find it. Does anyone know what this thing is??? I'm concerned I'll be charged for something when I talk on the phone b/c I inadvertently activated something that doesn't need to be on.

• Answer:

  I think that it is the In-Call sound enhancement/boost, like an equalizer. To change it or remove it, hit the menu key, select enhance call audio and select the one you want. The normal setting should take the icon away while in calls.