Figure 2
Mechanical tests comparing the viscoelastic foam substrate and silicone13. (a) Stress-Strain curve for viscoelastic foam cylinders of varying density. (b) EEG signal captured with the foam-based earplug from the ear canal of a person with strong blood vessel pulsation, observe no pulsation in the recorded EEG. (c) Stress-Strain curve for silicone cylinders of varying hardness. (d) EEG signal captured using the silicone-based earplug from the ear canal of the same person with strong blood vessel pulsation, observe strong contamination of the EEG with pulsatile artifacts, indicated by red crosses.
