1. A method for generating a noise reference signal, the method comprising: receiving a first input signal; receiving a second input signal, wherein the second input signal is different from the first input signal; performing, using processing equipment, a continuous wavelet transform of the first input signal to produce a first transformed input signal; performing, using processing equipment, a continuous wavelet transform of the second input signal to produce a second transformed input signal; generating, using processing equipment, a first scalogram from the first transformed input signal; generating, using processing equipment, a second scalogram from the second transformed input signal, wherein the first scalogram is generated based at least in part on the second scalogram; identifying, using processing equipment, regions in the first scalogram that exceed a predetermined threshold; and performing, using processing equipment, an inverse continuous wavelet transform on at least part of the first transformed input signal, based at least in part on the identified regions, to generate the noise reference signal.