  The bubble nucleation process in superheated droplet detector (SDD) is
associated with the emission of an acoustic pulse that can be detected by an
acoustic sensor. We have studied the neutron and gamma-ray induced nucleation
events in a SDD with the active liquid R-12 (CCl2F2, b.p. -29.8oC) using a
condenser microphone sensor. A comparative study in the low frequency region (~
0-10kHz) for the neutron and gamma-ray induced nucleation is presented here.
From the analysis of the waveforms we observe a significant difference between
the neutron and gamma-ray induced acoustic events.
