Good Morning Joan.
First, I can't answer your question about what this might be but I can tell you a couple of things that I have experienced. I have that swooshing sound in one ear occassionally and it seems to be getting more frequent. I just had it night before last and it just about made me crazy. I have no idea what it is but I am going to do some research and also talk to my neurologist about it. I have wondered if it is my "aura". I actually started getting a migraine several hours after the "swooshing". Your son describes it very accurately - it sounds like your blood pumping and you can hear it in your ear - it makes me crazy!
Also, I have a friend who's 12 year old daughter has been suffering terribly with headaches for approximately 9 months. She was originally diagnosed with the whol pseudo-tumor thing but no one pays much attention to the diagnosis. The neuro-opthamologist says she doesn't have the "true" signs of the pseudo-tumor. I believe the reason they diagnosed her with it is because one of her spinal taps (LP) came back with high pressure. Anyway, I don't put a lot of credit into that diagnosis. After having everything else ruled out, I truly believe she has migraines. She has been seen here in Atlanta and also at the Diamond Headache Clinic in Chicago. This is a child who was a competitive cheerleader, softball player, etc. before these headaches started. She is now not even able to attend school. It is so sad and nothing they try has worked. I will keep you updated and maybe between the two kids, we can find something. After reading about cluster migraines, (even though she doesn't fit the typical profile of being a 40 year old man), I believe her symptoms suggest that her headaches are cluster migraines. She has them every day, does not have the nausea or vomiting and can't lie down or sit still when she gets them. She wants to be sitting up and her legs move constantly. Her parents called the doctor in Chicago and requested home oxygen therapy for her to see if it would help. He prescribed it and they started it yesterday. For part of the day yesterday, her headache decreased but then by last night, it was severe again. So.....who knows if it will help.
Anyway, one thing you might consider if all of his tests come back normal, is trying to make your son an appointment with a Headache Clinic. I don't feel that a regular peds neurologist will be much help, but maybe....
Please keep us updated and I will let you know if I come across any answers for the whooshing noise or anything related to peds headaches..
DX: Migraines since June, 2006, kidney stones
RX: Daily - Verapamil, Trileptal
PRN: Relpax, Prednisone, Dilaudid, Lortab, Lidocaine Nasal Spray