[App_rpt-users] Noise reduction on receive audio from Allstar

Folks, I notice that when hams are noisy into their Allstar node or the repeater connected to the Allstar node, the noise on their signal seems to be higher pitch and accentuated. Some folks are always noisy and therefore difficult to copy. Does anyone else have this problem, and has anyone reduced the noise with either software running on the server or some hardware inserted in between the audio from the URI or CM108 dongle to the transmitter? I was thinking a DSP audio filter (more expensive than my whole node). 73, Eric 4Z5UG