How do you let things go through one ear and out the other?

My brother comes to us with his marital problems. We give him solutions as we see fit. He tries some, dismisses others. But he still comes for venting sessions. Today, he actually admitted that since we cant give him any workable solutions to his marital woes, then what he's doing is just venting. So how do I just hear what he has to say, but process it as blah, blah, blah? I mean, he's just venting, so this is all I need to do right? Same goes with my mom, she tells me about her life, n how she wishes it were different, or how I suck as a daughter and human, and how I would've still had a husband if I were a lady in the street n a freak in the sheets. This, after three yrs...u know, when it's been beyond repairable for some time now? So I'd also like it to b blah, blah, blah. Because I'm at a point where I care what they say, n want to respond, but know that my opinions on anything make NO difference to them...I'm just a sounding board. Thanks for any n all constructive criticsm. No, I cant move out. If ur gonna b nasty, please get ur two points for writing ur two cents elsewhere. thank you.