Ozy,
Perhaps I can help here. Some while back, I was closely involved with F-35 noise studies (all variants).
Of course perceived noise (i.e. the noise a person will hear) will be different for an F-35B hovering to an F-35A in the circuit. The F-35B will be close to the ground, the A will be a few hundred feet up. So, yes, a B in the hover will be noisier than an A in the circuit, as long as you are standing fairly close to the landing area.
The noise emitted from the main engine in the F-35 at max power is very nearly the same for all three types. For the F-35B in the hover, the main engine exhaust is actually delivering about 50% less thrust, as half of the engine power is being sent forward to the shaft driven fan. The noise signature around the jet during landing ops is higher than for the Harrier, but can be managed. I understand that sound insulation is being fitted under the F-35B deck landing areas, much as has been done for many years under CVNs' catapults.
The most severe noise issue with any F-35 variant is for the F-35C and the USN carrier flight deck catapult launch crew, who have to be close to the aircraft while it is at high power before launch. The F-35C's noise signature was found to be very close to 'legacy' jets like the Super Hornet, and was well mapped and understood, especially once the USN had carried out special trials in front of a Jet Blast Deflector (JBD).
For deck launch, F-35B noise is less of a problem than for the C, for much the same reason as landing - less energy is being generated by the very fast hot engine exhaust, and the forward lift fan exhaust is being directed at the deck, where it disperses rapidly.
The whole issue of F-35 noise has been very carefully addressed for many years, with BAE leading the effort in measuring and characterising the aircraft's external environment. This is complicated stuff and the team I worked with were absolutely world class - and recognised as such by their US counterparts.
The biggest problem with noise in the UK is not the aircraft, but the UK MoD's decision to impose limits for noise exposure set out by EU Noise and Vibration legislation. These are FAR more stringent than anything the US required, and have led to very extensive (and successful) efforts to protect QEC carrier flight deck crews.
Hope this helps a little
Best regards as ever to all those trying to keep the noise down,
Engines