Unless I am mistaken (and I frequently am) a big reason is the engine.
It appears to be a straight-pipe turbojet where most newer designs have a fan and bypass configuration.
Turbojets are almost categorically louder than even low-bypass fanjets. On many aircraft this is especially pronounced at and near idle power. The early DH
or Hawker 125 was seemingly louder on taxi than it was on the takeoff roll.
Happiness is not seeing another trite Ste. Maarten photo all week long.