Grounding of Dedicated lines

Hi everybody, this question is for any of you EEs out there or anybody who has been confronted with my situation.
Several years ago when I built my house, I included a dedicated audio room with three dedicated lines in the equipment/component room which is located at one end of the listening room. These lines are grounded to the house bus bar at the breaker /switch panel. I have read recently that the dedicated lines should be grounded at the house mains ground rod at the meter box.
My question is 1. how important is this anyway, 2. since the house is built,what would be the most efficient way to do it, and 3. what sonic benefits would I gain by regrounding?
The equipment room has access to an open area on the other side of one wall that has an earthern floor in which a ground rod could be driven into the earth. This space is underneath part of the house and is accessable from the outside by a door.
I would appreciate any comments , suggestions or instructions.
Thanks very much.
The way your dedicated branch circuit equipment grounds are now wired is the correct way.
Recently I a dedicated room with dedicated lines and my electrician did what you did for grounding. So I suppose it should be the correct way to do grounding
You will not gain any sonic benefits from altering your present grounding setup. And, yes, I am an EE.
Thanks all for your confirmation that my current method of grounding is correct.
I really do appreciate your comments.