Eleven Categories of Line Noise
 
 
- 1. White noise or Gaussian noise (background hiss or static on radios and telephones) 
- 
- is caused by the thermal agitation of electrons and therefore is inescapable. 
- is treated by increasing the strength of the electrical signal = increasing the signal noise ratio
 
- 2. Impulse noise (also called spikes) 
- 
- is the primary source of errors in data communications
- is heard as a click or a crackling noise 
- can last as long as 1/100 of a second
- does not affect voice communications but can cause a burst error in data transmission