Fizzing and buzzing is an expression I like to use to describe annoying fret rattle.
It can be caused by several factors and will compromise the playability and sound of the guitar.
On Acoustic, Electric and Bass Guitars fret rattle is usually the result of the following:
An action that is too low: This would be remedied by raising the action at either the nut or the bridge-saddle.
The internal truss rod is over tightened: By slackening the truss rod it would allow the string to vibrate without contact with the frets. How to adjust
Uneven fret wear along the fingerboard: This is a general wear and tear problem and is solved by honing the fret tops to a uniform height and then reprofiling the frets to recreate the correct shape. This process can be repeated several times before the frets have to be replaced.