Most distinctive are the Chris Kings with their "killer bee" buzz... Routine maintenance and lubrication with Chris King's lube can minimize the buzz.
Phil Woods can also get your attention, particularly on newer models where stronger springs were used. However, it's a more conventional pawl/ratchet sound. Again, routine cleaning and relubrication -- I use Phil Wood's green waterproof grease, no thinning -- will make them whisper quiet. I believe Phil Wood still thins their waterproof grease with some of their tennacious oil as the OEM lube.
White Ind., Shimano, and Hadley all sound pretty normal to me. We've got the White's on one of our road tandems and I've had Shimano's HF07 & HF08's on prior machines. Hugi's used to go BANG but they've purporedly redesigned the entire engagement mechanism such that they are no longer prone to failure and fall into the normal sounding hub grouping.