It is easy to decrease the volume of the bleep that you hear when you press any buttons on the HR2510, just locate the brown wire at pin 4 of J302, to completely shut off the bleep cut the wire, to just reduce its volume at a resistor in series with the wire, according to the person that sent me this mod a 150KOhm worked nicely, but you may need to experiment to get the level you require.

Thank you to moslef for sending me this info, and RogerBird for knowing the answer !