Thermal noise versus signal amplification. The thermal noise spectrum signal of the eight individual sensors is plotted from 0 – 18 kHz. The individual spectra were overlaid and were matching each other (the signal of the eighth sensor (blue) is masking the other individuals underneath). Applying the Savitzki-Golay filter allowed clearer extraction of the frequency information (in red) and to remove high frequency noise . Signal amplification using the Stanford instruments SR560 digitisers ranged up to 5000 fold. The vertical input range of the boosted signal was then precisely set with the 8-bit digitizer board. No additional spectral features appeared within the log scale in the y-axis.