HI, don't know you but I am SWL_ing over long QRL afternoons with the KIWI and many times the tuned channel gets empty.
That noise makes me sleep :\"> ..... but also in between CW long pauses the noise disturbs.
Please do not say : MUTE the browser audio ... now I make already so.
A simple software routine could reduce the empty channel noise to a barely audible noise like when listening to a CW station
and between the characters the noise level is almost zero.
Somewhere it is called :SQUELCH...my old FT1000 has it.
SIMPLE no ?