Noise measurements conducted on npn bipolar transistors have revealed that the emitter-edge dislocations give rise to both 1/f and g-r noise, the resulting noise increasing with the number of dislocations. In dislocated devices, an alpha of approx. 1. 8 multiplied by 10** minus **4 has been found which accounts for the base 1/f noise as mobility-fluctuation noise. A 1/f**2 burst noise spectrum was observed when dislocations are clustered.