  We experimentally investigate a partially shrouded sonic jet exiting from a
planar nozzle with a solid wall on one side at two different nozzle pressure
ratio ($\zeta=4$ and $5$). We experimentally show for the first time that the
inherent jet unsteadiness from the shock-induced flow separation on the wall
and the emitted noise in the far-field is strongly coupled. The partially
shrouded jet's lateral free expansion is also identified to be complicated,
three-dimensional, and the produced noise is directional. The emitted acoustic
pulses from the flapping-jet, the radiated noise from the shock-induced
separation on the wall, and the shock-shear layer interaction on the other side
of the wall are responsible for the generated acoustic disturbances. The
non-uniform aeroacoustic forcing on the top and bottom portion of the partially
wall-bounded jet shear layer leads to a self-sustained jet oscillation and a
discrete sound emission.
