Several thoughts, valve are susceptible to several things, microphonicsm RF and induced Electro Magnetic hum from EMF. 6922 valves are quite notorious for microphonics. this is basically caused by vibrations in the valve usually caused by loud air born vibration(music) most common in guitar amps, however as valves get older they can become more susceptible to this I believe.
The whooshing sound(ocean waves) you describe I have also experienced, I spent a great deal of time trying to completely eradicate this, swapping valves and checking earths, sometimes it would be worse than others, I went through the process of switching off and unplugging every other piece of equipment in the house in case it was and earth loop/feedback issue, whatever I tried I could not completely eradicate it.
However for the past 2 weeks I have been trying out various cables in my system to see if I can get an improvement in sound and presentation, yes I know that age old arguments is a cable is a cable, but I know from experience that different types of cables, material and construction, can cause tonal changes to a system and how music is presented. You may scoff but it is true.
Anyway back to your problem, as a result of cable swapping I came across two different issues, firstly when I put in a quite expensive cable I was trialing between the phono stage amp and the pre-amp, this caused a hum and you could see the speaker drivers moving at a 50hz frequency if you turned it up, swap the cables for some others and no issues. I came to the conclusion the cables are susceptible to induced mains pick up, I tried moving all mains leads as far away from then as possible but no joy, the cable works fine from pre-amp to power amp and no hum.
Next I wanted to use a very short Chord Anthem Reference cable from my phono stage to my pre-amp to do this I had to move my phono stag amp up 2 shelves, and re-route a load of other cables. The instant I switched on the original whooshing sound(ocean waves) was completely gone and I had a silent sound floor, this is quite import to get the best atoning experience from a system. The difference is quite significant and well worth the effort.
So my advice would be first mover the phono stage as far away from all other equipment and mains leads as you can, and see if the whooshing sound(ocean waves) goes or gets less, also try several different interconnects from other manufacturers and see if they improve matters, you want a good well shield one. As others have said check and play around with earths, and last of all try a pair of different valves.
Good luck.