Why does the feed sound like jackhammer

[Bublovely]

The scanner sounds like a jackhammer is this because they are switching to digital?? Sometimes it sounds like they have the mic keyed on but it goes away when a call comes in the scanner

 

[mule1075]

The scanner sounds like a jackhammer is this because they are switching to digital?? Sometimes it sounds like they have the mic keyed on but it goes away when a call comes in the scanner

Well what feed? That would help for a start.