Anyone heard these weird noises while scanning?

[sergentslaughter]

While I'm scanning, no matter if it's 2m, 1.25m or even 800mhz trunking, there's always this oddball noise that sounds like a cross between gun fire and a diesel engine running. At first I thought it was just control channels because I was solely 800mhz with a PRO-94 but I've been using lower VHF freq's and hearing it as well. I cannot figure out what the heck the noise is, now I have a BC996XT and a BC396XT and the same noise is still there so it isn't Digital nor is it a Control Channel. Can anyone offer me an explanation?

 

[bryan_herbert]

Can you provide an audio sample?

 

[mmckenna]

There are more digital protocols than you can shake a stick at, and more than what your scanner will decode.

What you describe is classic "digital" noise. On the ham bands, you could be hearing D-Star, C4FM, P25, MotoTrbo, NXDN, etc. Outside the ham bands, you could be hearing NXDN, MotoTrbo, TETRA, etc. Those are not limited to any specific band.
As for control channels, there are different kinds depending on the mode, and again, your scanner will not necessarily decode them.
Other than P25, there are no off the shelf scanners that will decode those. So, what your scanner does is just pump them out as analog, and you hear exactly what you are describing.
If you were to post your location and which frequencies you are hearing this on, likely someone could tell you exactly what they are.