Which radio are you using? You might have to tweak the AGC a little to clear things up. The nature of digital, also, there will always be some transmissions that make the troopers sound underwater.
Do you have the latest firmware download from Uniden came out about a month ago??? If not there is a uniden scanner forum on Radio Reference. They will direct you in there on how to get and upload the lastest firmware. There have been some updates that help. Also how is your signal strength? Low signal strength will do strange things. Sometimes just changing the radio's location slightly helps if you are able do that.